ARCHEll ON STEPIIANOSPHJERA PLUVIALIS (COHN). 169 



in general, so sweeping and comprehensive as to be totally unreasonable 

 and altogether untenable. 



I might, perhaps, have referred to one or two other cases, possibly 

 similar to those I have cited of an amoeboid condition of the protoplasm 

 within the vegetable cell. I say possibly similar ; for, as the records are 

 not sufficiently copious or exact, it does not seem at all certain whether 

 such may be really cases in point, or may be instances of the actual in- 

 gress from without of a true animal. Cienskowski' s observations* 

 show that his Monas parasitica can make its way into a vegetable cell 

 from without, as he witnessed it, through the cell-wall, within which it 

 puts on an amoeboid condition. I venture to imagine that it may be pos- 

 sible that some of Carter's cases may have been similar to that described 

 by Cienskowski, although I am not aware that the observations of the 

 latter have been confirmed by any other observer. 



In case observers should in future meet with vegetable cells show- 

 ing Amoeba-like structures within, special attention should therefore 

 be paid to this point, as to whether they are foreign intruding parasites, 

 or are really due to any phase or change of condition of the protoplasm 

 of the vegetable cell itself. There cannot be a question, however, as to 

 the accuracy of Dr. Hicks' and Professor Schenk's observations, and that 

 a parasite had nothing to do with the phenomena they describe. And 

 that the primordial cells themselves of Stephanosphaera actually became 

 temporarily changed as I have described, and not that they each be- 

 came the choice morsel of a burglarious Amoeba, is likewise beyond the 

 faintest shadow of a doubt. 



But, leaving out of view the Myxogastres, as well as any such cases 

 possibly but only conjecturally similar to the authenticated instances 

 here cited, I fancy it would not be difficult to find further examples, far 

 less pronounced and far less striking, it is true, than in Stephanosphaera, 

 Volvox, Moss, or Rhizidium, of that automatic contractility which in 

 these established cases makes itself so remarkable, as even to present 

 phenomena characteristic of a true Rhizopod. 



Let us take a look, for instance, at the figures of the zoospore of 

 (Edogonium at the moment of its escape from the parent-cell.f The 

 contents of a cell destined to become a zoospore become withdrawn 

 from the cell- wall, and somewhat contracted into a sub-elliptic figure ; 

 at one side there makes itself apparent a pale space, which is the place 

 whence afterwards is to originate a crown of cilia. The parent cell- 

 wall splits, and the zoospore makes its egress, often through a space 

 actually too small to allow it to pass without a modification of its form ; 

 and this, in such instances, is really what takes place. It may be said 



* Cienskowski, "Die Pseudogonidien," in Pringsheim's "Jahrbiicher fur wissen- 

 schaftliche Botanik;" Band I., 1857, pag. 371, t. xxiv., 2, 3, 4. 



f See the following, e. g. : Colin, " Untersuchungen iiber die mikroskopischen Algen 

 und Pilze," t. 20, Fig. 1, 2, 22, 23; Pringsheim's "Jahrbiicher fur wissenschaftliche 

 Botanilt," Band I., 1857, t. i., Fig. 13, 14, 15 ; Vaupell, " Iagttagelser over Befrugt- 

 ningen hos en Art af Slaegten Oedogoniuin," Fig. 4, 11, 12. 



