Chambers's encyclopædia; a dictionary of universal knowledge . Fig. 1 (copied from Greenes Manual of Protozoa). a, b, c, (I, various species of gregarina ; e, pseudo-navicula;; /, younger stage of a; jr, various psoiospermia. attach themselves to the surfaces on which theyare generally found. Anatomically, the G. consistof an extensible transparent membrane enclosinga granular mass, in which we observe a nucleussurrounded by a clear space. See Cells. Theseorganisms are colourless ; their locomotive powersseem very limited ; and they have neither mouthnor feet. On carefully watching them imder
Chambers's encyclopædia; a dictionary of universal knowledge . Fig. 1 (copied from Greenes Manual of Protozoa). a, b, c, (I, various species of gregarina ; e, pseudo-navicula;; /, younger stage of a; jr, various psoiospermia. attach themselves to the surfaces on which theyare generally found. Anatomically, the G. consistof an extensible transparent membrane enclosinga granular mass, in which we observe a nucleussurrounded by a clear space. See Cells. Theseorganisms are colourless ; their locomotive powersseem very limited ; and they have neither mouthnor feet. On carefully watching them imder the micro-scope, we observe two of them to come in surfaces in contact become flattened, and acyst or capsule soon forms around them andencloses them (see / and a in tig. 1). Numerousglobular vesicles are then produced in the interior,and these become ultimately metamorphosed intopecuHar bodies, which are termed pseudo-navicula;{a, e, in the fig.). The septum by which the twoG. were at first divided, finally disappears; the. Fig. 2 (copied from Greenes Manual of Protozoa). a, young amocbaj; b, older specimen ; c, a peculiar variety; I, a body resembling a nucleus. belonging to the Rhizopoda (q. v.), which at lengthdevelop themselves into young gregariuidse. Thecoalescence or conjugation of the G. is not posi-tively essential to the formation of ;,since they are sometimes seen to occiir within thebodies of single animals. We have followed, as we believe, the best autho-rities in placing the G. as adult forms of the groupof the Protozoa. There is, however, considerabledifference of opinion regarding the position theyought to occupy. Stein places tliem among theinfusoria, Leon Dufour, Leidig, Vogt, and others,place them under various divisions of the worms,while some have even held that they are vegetableforms. It is exceedingly probable that certain miniiteparasitic organisms, occurring both on and withinthe bodies of fishes, and to which the term
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