268 ORDER FLAGELLATA-PANTOSTOMATA. 



the groups of monads or so-called " zoogonidia." This would necessarily be the case 

 if Anthophysa was a plant ; on the contrary, however, the stem here, and in all the 

 true animal forms, is produced secondarily from the bodies of the animalcules, and 

 in the present instance in a highly interesting manner. Both Dujardin and Cohn 

 are among those who at an early date decided, on the grounds just stated, upon 

 the animal nature of this organism. Still more recently this type has been made 

 the subject of investigation by Professor H. James-Clark.* As in the z-di-atoi Monas 

 {Oikouwnas), Codosiga, and other Flagellate types treated of in his memoir, that 

 authority advocates for this animalcule the possession of a distinct mouth, and goes 

 so far as to indicate in his accompanying figures the exact position of the supposed 

 oral aperture, namely, on the anterior truncate edge immediately beneath the rostrum 

 or projecting lip-like border, and at the base of the two flagella. There is no doubt 

 that more frequently than otherwise the food-particles thrown back by the action of 

 the flagella do impinge upon this anterior truncate border, and are thus engulfed 

 somewhere near the point just indicated. Prolonged observation on the part of 

 the author has nevertheless elicited that not unfrequently the food-particles strike 

 against other portions of the surface of the body, and are then immediately entrapped 

 by an outflowing film of sarcode in a manner similar to that recorded in this 

 treatise of Oikononas, Spumella^ F/iyso?nonas, AmJ>himonas^ and numerous other 

 Pantostomata. 



Although advancing so strong, but undoubtedly mistaken an opinion upon the 

 food-assimilating function oi AntJwphysa vegetans, Professor Clark is altogether silent 

 respecting the opposite and compensating function, of the rejection or evacuation 

 of the digested refuse. Neither has that authority been altogether felicitous in his 

 interpretation concerning the nature and development of the supporting pedicle, which, 

 as presently shown, is intimately connected with the process of defecation. Upon this 

 latter point he thus expresses himself: "As to the development of the stem, I 

 think it quite certain that it grows out of the posterior end of the body. The best proof 

 of this is that I have frequently found a monad nearly sessile upon a clear spot, and 

 attached by a very short, faint, film-like thread. From this size upward, I have no 

 difficulty in finding abundant examples as gradually increasing in diameter as they 

 did in length ; this furnishing a pretty strofig evidence that the stem grotvs under the 

 influence of its oiun inflate powers, and is not therefore a deposit emanating fro7n the body 

 of the monad, except perhaps, as far as it may be nourished by a fluid circulating 

 within its hollow core." Professor James-Clark was much mistaken in thus ascribing 

 to the stem of Aiithophysa an innate power of growth independent from that of the 

 bodies of the monads. The function of getting rid of waste and digested particles 

 and that of building up the pedicle are in flict co-ordinate ; this supporting stem 

 being almost entirely composed of the food-particles cast out from the parenchyma 

 or endoplasm after the monads have extracted from them such nutritive qualities as 

 they possessed on their first inception. We have here indeed a phenomenon pre- 

 cisely parallel in kind, though differing slightly in degree, from what has been already 

 recorded on a previous page of Oikomonas obliquns, concerning which species it 

 was shown, that the food-particles were, after the extraction of their nutritive pro- 

 perties, passed out at the posterior extremity of the body, and accumulated in a 

 heap round the base of the pedicle. 



The more minute structure and actual mode of the growth of the stem of 

 Anthophysa vegetans, as ascertained by the author's recent investigations, may now 

 be considered. Under ordinary conditions this pedicle or zoodendrium is somewhat 

 flattened, tapering and narrowest at its fixed or proximal extremity, gradually 

 increasing in diameter as it approaches its junction with the terminal mulberry-like 

 group of monads. If the colony is an old one this pedicle is usually divided into 

 three or four branches, the extremity of each branch bearing its monad cluster. 

 The colour of the stem, where it has been formed some time, is a dark rusty brown 

 changing into amber colour, and finally becoming quite diaphanous as it approaches 



'Mem. Boston Sec. Nat. Hist./ vol. i., part 3, 1868. 



