La Cellula: Aspetti Morfologici e Metabolici Dei Suoi Organuli

Abstract

The cell: morphologic and metabolic aspects of its organelles. — Some aspects of the mechanism of the chloroplasts movement induced by light, it has been studied in «Elodea canadensis» leaves. Red, yellow and blue light induce the movement of the chloroplasts. Green light does not promote the movement. 5.10—⁵M CMU completely inhibits cyclosis. Photosynthesis is required for cyclosis. ATP alone, does not Substitute photosynthesis, however in the presence of green light, 5.10—³M ATP, pH 6.5, promotes cyclosis movement. It has been concluded that light has dual role in promoting the movement in «Elodea» leaves: first, inducing photosynthesis and consequently the ATP production; second, light is necessary to start the movement exciting a photo-receptor, visualized like a System Controlling the induction-repression of enzymes. It has been postulated that ATP produced by illuminated chloroplasts, saturated a «SSS» system, connected with another System, «SAV», lowering the plasma viscosity; ATP in this action is not necessarily used as energetic Compound. Successively, by means an unknow photoreceptor, the mechano-enzyme-system, «SEM», promotes cyclosis utilizing ATP as energic source. The movement stop when ATP is exausted or immediately, in the presence of ATP, when the photoreceptor is not working, like happens in the dark.     

Fissazione di C14O2 in Colture di Tessuti Vegetali « in Vitro »

Abstract

C¹⁴O₂ fixation in plant tissues « in vitro ». — In the present work it has been examinated the autotrophic and heterotrophic CO₂ fixation of explants of « Helianthus tuberosus » « in vitro » and the photosyntetic efficiency of leaves produced from buds of « in vitro » explants of « Cichorium intybus » compared with that of mature leaves from normal plants of the same species. From our results it is evident that « in vitro » explants of « Helianthus tuberosus », grown, in the light, are able to autotrophically incorporate C¹⁴O₂; the distribution of the radioactivity into the various fractions shows a large influence of the light on the neutral fraction containing sugars (50% of the total radioactivity). In the chlorophyllous explants the dark CO₂ fixation is obviously of heterotrophic type: 97% of the total radioactivity is incorporated in amine acids (43%) and the organic acids (53%); on the other hand in the dark grown explants the radioactivity is differently distributed between amino acids (59%) and organic acids (39%). Mature leaves from normal plants and leaves produced from buds of « in vitro » explants of « Cichorium intybus » incorporate the same quantity of C¹⁴O₂ when expressed per mg of chlorophyll; the different distribution of the radioactivity in the neutral and acid fractions could be explained in terms of a different utilization pathway of the photosynthates in the two tissues.     

Attività Fotosintetica di Alghe Marine Nella Grotta Delle Viole (Isola S. Domino - Tremiti)

Abstract

Photosynthetic rates of some algae in the marine cave « Grotta delle Viole » (Is. S. Domino - Tremiti). — The « Grotta delle Viole » is one of the several marine caves located along the calcareous rocky southern littoral of the Island S. Domino (Tremiti) in the Adriatic Sea. Morphologically this cave is a tunnel, which connects the open littoral sea with a little bay. Availing of these environmental factors, we have chosen three stations to measure the photosyn-thetic yield, under completely natural conditions, of algae particularly important for some marine communities, described in an other paper (see, Pignatti S. et al. 1967). In station 1 (fig. 1) we have a biotope with strongly reduced light and in the neighbouring stations 2 and 3, two biotopes exposed to sun-light. We have studied three species living in dark places (« Peyssonelia » cfr. « harveyana », « Palmophyllum crassum » and « Pseudolithophyllum expansum » two of well lighted habitas (« Padina pavonia » and « Dictyota dichotoma » and one of intermediate place (« Codium difforme ») Some information on the optical conditions of the seawater have been obtained with a photoelectric cell, filters were used to measure the red and blue light penetration (Tab. 1, 2). This part of the Adriatic Sea is characterized by high penetration of blue light. In the cave this light is highly predominant. The photosynthetic rates were measured in natural conditions by determining the output in time O₂ using the Winkler method (Tab. 3) and the CO₂ changes by measuring pH-changes in short time intervals with an original method using a submarine incubation cell, of our design, equipped with the electrodes of a pH-meter and a spot-light galvanometer as measure instrument. The data obtained with the latter method have been statistically analized, their significance discussed and reported in Tab. 4. On the basis of the results, the species, which are confined in places with reduced light intensity, show a low but measurable photosynthetic surplus only in their natural habitats, transferred in high-light intensity they show a deficit. This fact can suggest the hypotheses: deactivation of the chlorophyll in green and blue light or competitive inhibition due to the presence of accessory pigments. The species of sunny habitats transferred in low-light intensity show an assimilatory deficit, that in this case, with great probability, is due to the progressive reduction of the photosynthetic process. These considerations explaine also the observed distributions of the species and of the algal communities (fig. 1), since each of them is connected with a light optimum. It seems important moreover to note that here, for the first time, data are given also on photosynthetic activity of Lithothamnia.     

Palmar ridge systems

A six — or seven — (fingers) «sites» system with sequential invading of interdigital ridge bundles agrees very well with actual data from literature. The palmridges of the left hand lag one «period» behind those of the right hands. Main line formulas and the regularities in their frequencies are to a large extent predictable and can be understood from the 7- «sites» model proposed in this publication.     

Azione della luce sulla crescita allo stadio di plantula di un mutante clorofilliano di Triticum durum Desf

Abstract

ACTION OF LIGHT ON SEEDLING GROWTH IN A YELLOW-GREEN MUTANT OF TRITICUM DURUM DESF. — Dry grains of Triticum durum cv. « Cappelli » and its radiation-induced yellow-green mutant were sown in sand in four environment, different for light conditions (daylight, artificial light, ultraviolet rays, darkness), having all the same temperature (23°C.). Seven days after sowing, the following data were registered: a) growth (in cm.) of the shoot and of the longest root; b) fresh weight (in gr.) of shoots and roots; c) water content of shoots and roots.

The following main results were obtained:

1. the yellow-green mutant always shows less growth and less weight increase than normal « Cappelli », with the exception of the seedlings grown at daylight, which have shorter shoots and longer roots than the normal « Cappelli » but the same weight:

2. artificial light, besides depressing the growth of the roots of the yellow-green mutant, which becomes green under these conditions, induces a remarkable decrease in the water content of the roots of the two wheats.

     

Sulla Presenza di Ificellarioli e di Conidi in Mieobionti Lichenici Coltivati in « Vitro ». Riassunto

Abstract

On the presence of « hyphycellariola » (swollen celles) and conidia in three lichenized fungi cultivated « in vitro ». — The Authors refer to the presence of « cellariola » (and « hyphycellariola ») found in pure cultures « in vitro » of the mycobiont of Xanthoria parietina and describe the morphology of conidia in the fungus isolated from Sarcogyne similis and Acarospora fuscata.

As far as the « cellariola » and « hyphycellariola » are concerned, it is the first note relative to the mycobionts of Lichens.

The Authors report the data of the utilized medium and the morphological observations.

This previous studies will be intensified by further research.     

Una Struttura Comparabile Con I Lomasomi Nelle Cellule Austoriali di Cuscuta Pentagona Engelm

Abstract

A structure comparable with the lomasomes in baustorial cells of « Cuscuta pentagona » Engelm. — Electron microscopic observations of haustorial cells in « Cuscuta pentagona » revealed to the A. the presence of some vesicular structures, outside the plasma membrane, comparable to the lomasomes of Moore and McAlear. The vesicles usually group in a bag of the plasma membrane and show an envelope consisting of unit membrane; their shape and size are variable and some of them are not well distinct while some others show ribosome-like bodies inside .In the examined cells the plasma membrane shows prominences which are in connection with the vesicle membrane, so that the A. thinks it possible the derivation of the vesicles from the peripherical cytoplasm. The function of these structures is not yet explained; they are only found in non photosyntetic cells, such as some Mycophyta, dark grown « Avena » coleoptiles and dodder's haustorial cells. The previously ultrastructural researchs on dodder have not pointed out lomasomes, which seem to be exclusive of the haustoria, so that it is possible to suppose a connection between the lomasome function and that of the haustoria.     

Insediamento e Diffusione di Buddleia Davidii Franch

Abstract

«Buddleya davidii» in «Valtellina» (North Italy), its settling and diffusion. — Vegetational areas where «Buddleya davidii» is naturalised in Valtellina are described and the subsequent phases are followed through 18 years.     

Der Neodarwinismus als axiomatisierbares deduktives System und das Problem der Anpassung und Selektion

In the last decade numerous evolutionary models have been proposed and intensively discussed. Surprisingly, the logical analysis of these different hypotheses is not of great importance in this debate. As a matter of fact, Neodarwinism is a consistent deductive system which is based on few but wellconfirmed axioms. Hence, very often, precise statements and definitions of standpoint can be made. This is exemplified by some repeatedly discussed models concerning the problems of Darwinian »adaptation« and »natural selection« 1. Following the logic of the Neodarwinian theory, extinction can only be the result of overspecialization if some very unusual assumptions are made. 2. The hypothesis of »punctuated equilibrium« GOULD 1982), the »effect hypothesis« (VRBA 1983) and the stochastic evolutionary model SCHOPF 1979) include elements which are logically inconsistent with the »modern synthesis«; they could be »true« only if at least one of the neodarwinian axioms (so far not disproved) is negated.     

Saxifraga Berica (Béguinot) D. A. Webb E Asplenium Lepidum Presl Sui Colli Berici

Abstract

«Saxifraga berica» (Béguinot) D. A. Webb and «Asplenium lepidum» Presl on the «Colli Berici». – We have identified a new association in the small caverns of the calcareous rocks in the hills of the north-eastern zone of the «Colli Berici», rising from the Italian plain near Vicenza. We have adopted for this association the name: ADIANTO-SAXIFRAGETUM BERICAE. This phytocoenose is characterized by the endemic «Saxifraga berica». We have found new stations of this remarkable plant and reported some features of this species to complete the diagnosis of D. A. Webb. In two station of this association we have found also the rare «Asplenium lepidum», new for this region.     

Phagnalon Metlesicsii Nova Sp. Aus Westsizilien,Mit Einem Überblick Über Die Gruppe Von Phagnalon Rupestre Im Mittelmeerraum

Abstract

«Phagnalon metlesicsii», a new species from Western Sicily, with a survey of the «Ph. rupestre» — group in the Mediterranean Region. — Phagnalon metlesicsii, a new species of the complex Ph. rupestre — Ph. graecum, is described. It is entirely glabrous and occurs in Western Sicily (M. Cofano) on vertical limestone rocks, nearly 200 mts. above the sea, in community with a flora particularly rich on endemics. The variability of the whole complex is discussed and some infraspecific taxa are proposed.     

Crepis Bursifolia L., Nuova Stabile Inquilina della Flora Ligustica della Riviera di Ponente

Abstract

«Crepis bursifolia » L., new permanent tenant of the flora in west ligurian coast. — The author declares the permanent presence of « Crepis bursifolia » L. in Liguria, and informs about new stations of this species along the western riviera. The relates, furthermore, the unfavourable results of his close investigation to verify the eventual presence of further station of « C. bursifolia » L. found by former researcher.     

Nuovi Dati Sulla Distribuzione Di Isoétes Malinvernianum in Lomellina

Abstract

New data on the distribution of « Isoëtes malinvernianum » in Lomellina. — The Author relates the discovery of many new stations of Isoëtes malinvernianum in Lomellina (Province of Pavia). Many observations carried out in these new localities and in the most part of the already recorded localities near Novara and Vercelli have allowed him to modify some convincements on the habitat of this well known endemism. So he reports that Isoëtes malinvernianum vegetates not only in the waters of « fontanile » but also in waters of the most different sources, that this species is not solitary but accompanied by many species as Callitriche palustris, Fontinalis antipyretica, Sagittaria sagittifolia, Vallisneria spiralis, Potamogeton crispa and few other species more. Isoëtes malinvernianum, besides, is not damaged by dredge works in the canals and is present not only in morainic soils and in the diluvial soils transformated in ferreto but also in the terraced flood named with old terms as « Terrazziano » or « Diluvium recente » and in the diluvial soils of the « Alluvium ». Now at least it is not possible to ascribe plant communities of which Isoëtes malinvernianum makes part to a well defined association.     

Studio Comparativo della Struttura e del Ciclo Biologico di Due Diatomee di Acqua Dolce: Navicula Minima Grun. E Navicula Seminulum Grun.: III. Esame Dei Caratteri di Navicula Minima Grun. E di Navicula Seminulum Grun

Abstract

Comparative study of the structure and of the biological cycle of two fresh water diatoms: « Navicula minima » Grun. and « Navicula seminulum » Grun. III. Examination of the characteristics of « N. minima » Grun. and « N. seminulum » Grun. — After studing separately the Navicula minima Grun. and the Navicula seminulum Grun. the various characteristics of the two have been compared and contrasted for purpose of classification. The form and dimentions of the frustules, the density and the structure of the streaks, the structure of the walls, the life circle, aspects of their growths, and some anomalies, most especially, as regards the streaks were examined. It was found the among such numerous characteristics, only one, that is, the presence of the streaks formed by double rows of pores in N. seminulum rather than of a simple file as in N. minima makes one thinks that, in spite of strong similarities existing between these two Naviculae, they are to be regarded as belonging to e different systematic classes. However, their actual positions in taxonomy May-June be defined by further research into the structures and the variabilities of the frustules of other species of Naviculae similar to those examined.     

La Vegetazione e L'ecologia Di Pratofiorito (Appennino Settentrionale)

Abstract

Ecology and vegetazion of mount Pratofiorito. — The author examines position, climatic conditions, geological nature and vegetation of Mount « Pratofiorito » in the Tuscan Appennine.

Mount Pratofiorito is a residue of secondary rocks and derived soil surrounded by tertiary and quaternary rocks and soil.

Its vegetations is actually constituted by grass-land and so it differs-from that of the neihbouring mountains which comprises the flora has been made. This list was then comparend with spades found in the adjacent beech and helm-oak zones.

From these comparisons one can deduce thath the meadow of « Graminaceae » and « Cyperaceae » growing on Mount Pratofiorito may bed considered as a grass-land resulting from the degradation of an arboreal zone, problably from a beech-wood.     

Sulla Terminologia dei Processi Apomittici

Summary

The Author observing the great disagreement of the terminology usually adopted for the apomictic phenomena, examines the whole series of the phenomena noted both in regards of the formation of the gametophyte and of the embryo. The forming of the gametophyte is fixed on the base of nature of its original cell, normally a haploid spore or »haplospore« (phenomenon of the »haplospory« following the regular meiosis), rarely a diploid spore or »diplospore« (phenomenon of the »diplospory« following the irregular meiosis, as for instance in the case of restitution nucleus, etc.). The original cell can be at least represented by the same cell that usually is the spore mother cell, whether for the outward causes, or for inward causes is lacking the usual reductional process. For the failure of the meiotic process, such a cell cannot be called »spore«.

A cell of the somatic tissue of the sporophyte can even become the original cell of the gametophyte always in case of the absence of the meiosis. These two last cases of apospory are respectively called: »somatic apospory« and »gonial apospory« (= germinal apospory) (Chiarugi 1926).

The formation of the embryo is fixed on the base of the nature of the fecundation. The principal phenomena of the fecundation are represented by the following cases: »amphigamy« (or eugamy, or gamy), »semigamy, »pseudogamy«, »apogamy« »parthenogenesis«. The A. uses the term »apogamy« both for the diploid eggs and for the haploid eggs in which the stimulation of the division is produced by the pollen-tube or by male nuclei, in absence of the gamy.

The term »parthenogenesis« is restricted to the division of the haploid or diploid eggs in which the stimulation is not caused by pollen-tube nor even for the great reason, by the male nuclei existing in it.     

On the phylogeny of human morality (ten years later)

Sociobiological explanation of altruism, through theories as such «kin selection», cannot reach the wealth of human morality; it is necessary to add some specific traits in order to explain the human way to ultrasociability. Some of them appear within the classical school of «moral sense», distinguishing between two different levels («motive to act» and «moral criterion») of moral phenomenon. Due to the complexity of criterion level, here we deal with a broad model of human moral phenomenon, proposing three different dominions («motive to act», «personal criterion», «collective values»), and trying to find possible phylogenetic roots of them through a cognitive approach.     

Le Piante e la Musica. Riassunto

Abstract

The Plants and the Music. — The valuable contribute that the Biology may offer to the scientific study of the « essence » of the Music is pointed out. The plants as Animals and as remotest ancestors of the humanity, contribute to form what the A. calls the « Promusic », that is the natural and necessary starting-point of the evolution of the Music, which is exclusive work of the man. The Plants particularly, although indirectly, showing wonderful instances of transformations and associations of simple in complex forms, as well of colours and scents, have certainly inspired to the Man the Harmony, which is just in Music the Art, unknown to the Ancients, in associating aesthetically sounds and timbres.     

Residui di vegetazione spontanea in Roma

Summary

The A. describes a large remainder of natural vegetation at the periphery of Rome on the «Monti Parioli». Mainly it is Quercus Ilex macchia — evergreen wood, which becomes on the septentrional declivities Quercus Ilex — Quercus lanuguinosa mixed wood; here among the shrubs some not typical mediterranean elements are contained.     

Ricerche Sulla Morfogenesi Dei Plastidi Clorofilliani

Abstract

Studies on chloroplast morphogenesis. The effect of sucrose feeding and light intensity on the plastids of etiolated plants. — The changes in the fine structure of the plastids of etiolated Bean plants, dipped into water or in various sucrose concentrations, for 24, or more, hours, and exposed to conditions of darkness and weak light, were studied at the electron microscope, and protochlorophyll, chlorophyll a and chlorophyll b contents were determined. When the etiolated plants are dipped into water or sucrose solutions, in the dark, rows of tubules and lamellae, often stacked and resembling small grana, are formed in the plastids. These structural changes of plastids of the plants exposed to conditions of darkness, where no protochlorophyll was converted to chlorophyll a, are quite similar to those described by several Authors for plants exposed to light conditions and thought to coincide with the protochlorophyll-chlorophyll transformation. Thus, the preservation of the « Kristallgitterstruktur » of the vesicular centers, or, instead, their transformation into a lapse cluster of tubules, does not seem to be related with protochlorophyll accumulation in them; indeed, an increase of protochlorophyll contents was observed both with the preservation of the crystalline structure, and with its transformation, and low protochlorophyll contents did not always coincide with the transformation of the vesicular centers. In the plants exposed to weak light (1 ft-c) there is chlorophyll a and b accumulation, and a more pronounced tendency toward stacking of tubules and lamellae. In the plants exposed to weak light, dipped into water or sucrose solutions, at the lowest concentrations, and for the shortest periods, the vesicular centers are transformed into clusters of tubules; but with higher sucrose concentrations, or longer dipping periods, their crystalline structure is preserved, just as if their preservation would depend only by an adeguate nutrients supply.

The arrangement of normal lamellae and the formation of grana connected by intergrana lamellae occur, anyhow, only when the etiolated plants are exposed to « high » light (630 ft-c). But chlorophyll accumulation is possible under « weak » light (and a stacking of tubules and lamellae, resembling small grana, also occurs), when sucrose is supplied. The achievement of the « normal », complete structure of the chloroplast is, therefore, here interpreted in the sense that it represents only the functional aspect of its organization, determined by a light intensity favorable to its photosyntetic activity, which is not directly necessary for the synthesis of the contistuents of the lamellar system (chlorophylls, phospholipids).