Le Genre Trimyema Lackey et les Caracteristiques Structurales des Ciliés Trichostomatida

SYNOPSIS. The longitudinal kineties of the holotrich ciliate Trimyema marinum each bear only three widely spaced cilia; but these cilia are located at identical horizontal levels so that they comprise three helicoidal ciliary bands running around the anterior pole of the organism. The two kineties whose cilia are found most anteriorad, located in a right dorso-lateral position on the body, are exceptional, however: they are prolonged anteriorly, bearing numerous short additional cilia.
These two "polykineties" wind clockwise around a kind of apical disc; their distal extremities continue to curve, dipping into a "prebuccal invagination" in which they may be said to constitute a vestibular ciliature.
In spite of its rather unique characteristics, the curious anatomy of this ciliate does conform to the organizational type recognized for holotrichs of the order Trichostomatida.     

Fine Structure of Trichomitus batrachorum (Perty)*

SYNOPSIS. Trichomitus batrachorum (Perty) shares with Trichomonadinae most of its fine-structural characteristics, especially those pertaining to the undulating membrane that consists of a high body fold, enclosing the loop-shaped, periodic marginal lamella, and of the recurrent flagellum applied to the fold. This flagellate has also certain structures, i.e. the costal base, comb-like organelle, and well developed marginal lamella, in common with Monocercomonas. It shares with Hypotrichomonas the costal base; large pelta; very fine fibers perpendicular to, and connecting the axostylar microtubules; structural details of the most proximal segment of the marginal lamella; and general relationships between dorsal body fold (poorly developed in Hypotrichomonas) and the recurrent flagellum. All these electronmicroscopic findings support the crucial position of Trichomitus in the evolutionary sequence Monocercomonas→Hypotrichomonas→Trichomitus→ Trichomonadinae suggested previously by lightmicroscopic observations. Further, Trichomitus shares with all Tritrichomonadinae the comb-like structure, not found either in Hypotrichomonas or Trichomonadinae; and it has in common with Tritrichomonas also the costa with Type A periodicity, being the only member of Trichomonadinae with this type of supporting organelle. It appears, therefore, that Trichomitus-type organisms represent an important link in the evolution of all Trichomonadidae from Monocercomonadidae.     

Reisen ins Wallis im Sommer 1852

Ohne Zusammenfassung     

Reisen ins Wallis im Sommer 1852

Ohne Zusammenfassung     

Reisen ins Wallis im Sommer 1852

Ohne Zusammenfassung     

Reisen ins Wallis im Sommer 1852

Ohne Zusammenfassung     

Reisen ins Wallis im Sommer 1852

Ohne Zusammenfassung     

Le Coincement,un processus ecologique

Résumé Le coincement (en anglais cornering, en allemand VerdrÄngung, en espagnol acuñación, en portugais acunhaÇÃo, en italien acantonazione) est un processus résultant du rétrécissement d'un gradient écologique qui entraíne une moindre satisfaction des exigences d'une espèce ou d'une biocénose tout entière. Ce rétrécissement peut avoir une origine physique ou biologique. Il cause un rajustement entre eux de l'exploitation de leur milieu commun par les membres de la biocénose. Il a comme effet un remaniement des positions écologiques des taxa en présence, qui peut aller jusqu'à l'élimination totale de certains d'entre eux. Le processus contraire, l'effusion, entraÎne une expansion ou une ascension dans l'ordre écologique de certains membres jusqu'ici subordonnés. Ce mécanisme paraÎt Être général et se manifeste à divers ordres de grandeur dans l'espace et dans le temps. Eminemment réversible, il peut, à l'occasion Être alternatif et on pourra rencontrer des espèces et des biocénoses entières qui sont conditionnées à l'alternance elle-mÊme plutÔt qu'au coincement ou à l'effusion.

---

Summary Cornering (in French coincement, in German VerdrÄngung, in Portuguese acunhaÇÃo, in Spanish acuñación, in Italian acantonazione) is a process resulting from the narrowing of an environmental gradient which induces a lesser fulfillment of the requirements of a species or of a whole biocenosis. Such a narrowing may have either a physical or a biological origin. It causes a mutual re-adjustment of the species involved in the exploitation of the total resources of their environment. It effects a shift in the ecological status of the taxa which may culminate in the total elimination of some. The opposite process, effusion, produces an expansion or a rise in the ecological order of certain heretofore subordinate members of the community. Such a mechanism appears to be quite generalized and is manifest at various orders of magnitude in space and time. Eminently reversible, it is even occasionally alternating and some species or communities may be conditioned more truly by such an alternation than by cornering or effusion.

---

Zusammenfassung VerdrÄngung (im Englischen cornering, im Französichen coincement, im Spanischen acuñación, im Italienischen acantonazione, im Portuguesischen acunhaÇÃo) ist ein resultierender Prozess einer Verengerung in der Abstufung der verschiedenen Umweltfaktore, die keine optimale Entwicklung einer Art oder einer Biozönose ermöglicht. Eine solche Verengerung kann sich sowohl auf physikalische wie auf biologische Ursachen gründen. Sie hat eine Ausnützung der hierdurch entstehenden Möglichkeiten durch die herumstehenden Arten zur Folge. Das Resultat ist eine Verschiebung in dem ökologischen Status der bisherigen Taxa, welche die vollstÄndige Elimination einiger deren zur Folge haben kann. Den entgegengesetzten Prozess nennt man im Englischen effusion; er führt zu einer Expansion oder zu einer ökologischen Rangordnungerhöhung einiger bis daher in der Biozönose nicht im Vordergrund tretenden Arten. Es stellt sich heraus, dass diesem Mechanismus eine ganz allgemeine Bedeutung zukommt, sowohl in Grösze, wie in Raum und Zeit. Im höchsten Grade umkehrbar, sogar gelegentlich abwechselnd, kann man Arten, sogar ganze Biozönosen finden, die mehr noch durch Abwechslung als durch VerdrÄngung oder effusion konditioniert sind.

---

---

Contribution No 1033 du Département de Botanique de l'Université du Michigan.

---

Actuellement directeur de l'Institut Botanique de l'Université de Montréal.     

A Proposed Organization of the Genus Blepharisma Perty and Description of Four New Species

SYNOPSIS. The following four subgenera. I based chiefly on the form of the macronucleus, are proposed for thr genus Blepharisma Perty 1852: 1) Compactum , having a single compact interphase macronucleus. Type species B Compactum hyalinum Perty. 2) Filijormis , having a vermiform or tubular elongate interphase macronuclcus. occasionally doubled or even fragmented in individuals. Type spcies B. (Filiformis) intermedium Bhandary. 3) Blepharisma , having an interphase macronucleus with two or more nodes usually connected by a very thin strand between the nodes. Type species B. (Blepharisma) Perisicinum Perty. 4) Halteroides , having an interphase macronucleus in two nodes connected by a thick strand. Type species B. (Halteroides) tropicum Bhandary. Differences between the subgenera also can be found in the size, pigmentation, presence or absence of cysts and conjugaion 26 species are presented.
While integradations between the subgenera and species exist, it is felt that separation of the four groups is warranted and may indicate possible evolutionary trends within the genus.