鹅观草属三个种的形态变异与核型的研究

本文通过对鹅观草属的三个种:鹅观草(Roegneria kamoji Ohwi)、纤毛鹅观草(R. ciliars (Trin.) Nevski)和竖立鹅观草(R. japonensis(Honda)Keng)的形态学比较和核型分析研究了该三个种的系统关系。R. kamoji与R. ciliaris、R. japonensis形态上的差异明显,而后二个种差异甚小,难以进行划分。R. kamoji的核型公式为:2n=6x=42=30m+8sm+4SAT;R. ciliaris为:2n=4x=28=18m+6sm+4SAT;R. japonensis为:2n=4x=28=18m+6sm+4SAT。t-测验的结果表明R. ciliaris与R. japonensis的核型无显著差异。因此笔者认为R. ciliaris和R. japonensis应合并为一种系内的分类群。     

ESSENTIAL LEAF OILS IN REPRESENTATIVES OF THE AURANTIOIDEAE (RUTACEAE)

The distribution of essential leaf oils in representatives of 12 genera in the Aurantioideae has been studied by gas chromatography. Of the individual oil components, 40 were identified by retention times on two columns, augmentation, and some by IR spectrophotometry. Twelve groupings of components were established and these compared between the tribes Clauseneae and Citreae , among the subtribes clauseninae , balsamocitbinae , and citrinae , and between the “primitive” and the “near citrus group.” The essential oils conform to the botanical groupings, except for Pleiospermium in the citrinae and Murraya in the clauseneae. Fortunello crassifolia (Citbeae ), a possible garden hybrid, seems to be more closely related to the Clauseneae , the remote citroids, than to the near Citrus group. Atalantia also might be an intertribal hybrid with remote or other citroids. A specimen of Aeglopsis chevalieri (balsamocitbinae ) from Florida appears to be of hybrid origin with the parental source close to Citrus.     

PHENOLOGY OF THREE ANT SPECIES IN THE SOLOMON ISLANDS

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Seasonal variation in the composition of colonies is described, with particular reference to the incidence of sexual castes. The ant species are Oecophylla smaragdina F., Iridomyrmex cordatus Fr. Smith and Anoplolepis longipes Jerdon.     

THE CONCHOCELIS PHASE OF THREE SPECIES OF PORPHYRA IN CULTURE

The Conchocelis phases of Porphyra perforata f. patens, P. cuneiformis and P. nereocystis were cultured from spores in a sterile artificial medium at 12 C and with 25 ft-c illumination for 10 hr daily. The cultures showed differences in duration of the vegetative phase, sporulation, liberation of spores, and the return to the leafy phase. Morphological differences were also noticed. Since the 3 species were grown under identical conditions, it is inferred that these characteristics are probably different for the 3 species studied.     

STUDY OF THE ESSENTIAL LEAF OILS OF THE GENUS MONARDA (LABIATAE)

Vapor-phase chromatographic patterns obtained from the distilled essential oils of 20 taxa in the genus Monarda (Labiatae) are discussed. The influence of leaf tissue maturity, plant habitat, and oil storage upon the composition of the essential oils was investigated, as well as similarities of leaf and flower oils in the same plant. The taxa of the subgenus Cheilyctis have very similar chromatographic “fingerprints” which confirm their homogeneity. On the other hand, the polyploid subgenus Monarda has heterogeneous patterns of essential oil composition among its species. A population of M. fistulosa gave evidence of being a chemical race.     

THE DEVELOPMENT OF THE SENSILIUM OF THREE FLEA SPECIES

Abstract The result of a study on the internal structures during the development of sensilium and anal segment from first instar larva to adult of Leptopsylla segnis (Schinherr 1811), Monopsyllus anisus (Rothschild 1907) and Ctenocephalides felis felis (Bouche 1835) is reported and summarized as follows: (1) The development of the sensilium and anal segment of these fleas is essentially the same. (2) The first sensilium rudiment appears in the early third instar larva on the anterior one-second part of the tergite of the tenth abdominal segment, and in prepupa the eleventh abdominal segment which is composed of the dorsal and ventral anal lobes is formed, and in the pupa the sensilium and its frame are fully developed. (3) The differenced of opinions on the terminal segments of the flea are discussed.     

THE SEASONAL CYCLE OF PHLOEM DEVELOPMENT IN JUNIPERUS CALIFORNICA

In Juniperus californica, all sieve cells of the previous season's phloem growth increment overwinter in a mature state. Initiation of cambial activity begins in early March and, by the end of March, the oldest sieve cells that overwintered lose their contents and die. By mid-April, even the youngest sieve cells of the previous season's growth increment have lost their contents. The period of greatest cambial activity begins in the last half of April and continues through May. With the slowing of cambial activity in June, callose begins to collect on the sieve areas of the first-formed sieve cells of the new increment. By July, the cambium and phloem are in a dormant state. Initiation of phloem production precedes that of the xylem by about 1 month. Production of new xylem and phloem ceases simultaneously in July.     

STRUCTURE OF TRACHEIDS IN THREE SPECIES OF LYCOPODIUM

The structure of tracheids in Lycopodium lucidulum, L. clavatum, and L. tristachyum was studied with the light microscope. Protoxylem development is at least sometimes and possibly always mesarch in indeterminate axes of all three species. Centrifugally formed protoxylem elements are reticulate and discontinuities in the secondary walls of these elements are sometimes conspicuously bordered. Wall thickenings of first formed protoxylem elements consist mainly of indirectly connected rings. Late centripetally formed protoxylem elements and transitional elements have a reticulate secondary wall pattern. The narrowest metaxylem elements have circular bordered pits while in wider metaxylem elements pits are bordered and may vary from circular to scalariform. Pitting is uniseriate to triseriate in tracheids of all three species, and intermittent tetraseriate pitting was occasionally observed in L. lucidulum. Crassulae occur in tracheids of the three species, and in L. clavatum an additional framework, probably representing thickened compound middle lamella, is also present. Pits often appear helically arranged, and in all three species pits are connected by thin areas in the secondary wall. Macrofibrils approximately 0.5 μ wide were observed in tracheids of the three species. In L. clavatum the arrangement of macro-fibrils was predominantly bidirectional.     

OBSERVATIONAL LEARNING IN THREE SPECIES OF BIRDS

White-throated Sparrows Zonotrickia albicollis, Fork-tailed Flycatchers Muscivora tyrannus and Black-capped Chickadees Porta atricapillus were placed in experimental situations where they could watch a trained companion uncover a hidden mealworm. After a period of watching its companion find the concealed mealworm, the observer bird was isolated visually from the other bird. While in isolation the observer birds approached, touched and pecked at a hidden food tray significantly more often than control birds which had not had an opportunity to observe a trained companion. However, the experimental birds failed to learn from observation alone how to uncover the concealed mealworm. But if rewarded in the presence of the companion bird (by taking a mealworm from it or by uncovering a mealworm as a result of local enhancement), then the observer bird frequently did come to find the prey in isolation. It is suggested that the interaction between observational learning and a bird's reinforced socially facilitated experience could assist in the development and expansion of a bird's behavioural repertoire.     

三种烟草属植物的核型分析

本文对三种烟草属植物进行了核型分析。粘烟草Ｎｉｃｏｔｉａｎａｇｌｕｔｉｎｏｓａ为二倍体,其核型可简式为：２ｎ＝２４＝１０Ｍ＋１０ｍ＋４ｓｍ（２ＳＡＴ）;内索菲拉烟草Ｎ．ｎｅｓｏｐｈｉｌａ和斯托克通氏烟草Ｎ．ｓｔｏｃｋｔｏｎｉ可能均为双二倍体,其核型简式,前者为２ｎ＝４８＝６Ｍ＋２０ｍ（２ＳＡＴ）＋１８ｓｍ＋４ｓｔ,后者为２ｎ＝４８＝１４Ｍ＋１２ｍ＋１８ｓｍ＋４ｓｔ。此外,作者对供试材料的染色体基数、倍性及随体等问题进行了初步讨论。