326 M. A. Schneider's Contributions to the 



in the form of a small knob, until at last the filiform portion en- 

 tirely disappears, and in place of the filaments, two vesicles are 

 seen at the anterior extremity of the investing membrane (fig. 15). 

 I have observed a similar contractibility of the substance of the 

 filaments in a Bodo which is most nearly allied to Bodo grandis, 

 Ehrbg. As this possesses not three filaments only, as seen by 

 Focke (Ehrbg. p. 34), but often as many as five, the vesicles pro- 

 duced in this manner cannot easily be overlooked. I cannot 

 however state with certainty, whether all the individuals which 

 undergo this change invest themselves with cysts. When in- 

 fusions containing Polytoma are dried slowly, individuals with 

 the vesicles just described are found in the deposit, but no cysts, 

 and it is not impossible that such individuals may assist in the 

 continuation of the species in some other way. 



Nearly allied to Polytoma is the Chlorogonium euclilorum of 

 Ehrenberg *, which consists of a firm, transparent, fusiform in- 

 vesting membrane, with which I was not able to obtain any re- 

 action for cellulose. Its interior is filled with a homogeneous 

 green mass, which is generally somewhat rounded behind ; the 

 green colour disappears in front, where the mass is distinctly 

 connected with the filaments inserted in the apex. In the middle 

 there is a transparent, round nucleus, the reddish halo sur- 

 rounding which is extended in a spindle shape towards the two 

 extremities. The surface of the green mass is completely covered 

 with reddish spots (as many as twelve), but none of these are of 

 such a fine red colour as the eye-spot of Euglena. 



Ehrenberg describes Chlorogonium as possessing an eye; he 

 says, — " The eye of Chlorogonium is very distinctly marked, but 

 very minute, so that it may easily be overlooked.^' Unfortu- 

 nately during my observations upon this creature I had not 

 Ehrenberg's work at hand ; I cannot however call to mind that 

 one of the reddish spots was unusually distinct. I could not 

 discover a contractile space ; but if this were no larger than in 

 Polytoma, it would require uncommon acuteness of vision to 

 distinguish it from the non-contractile reddish spots. Divi- 

 sion takes place in the interior of the investing membrane, in 

 exactly the same manner as in Polytoma. The number of indi- 

 viduals produced is never less than four, but often as many as 

 thirty-two — in the latter case they are very small, but always 

 resemble the parent in other respects. A spherical state of rest 

 also occurs. It appears that when the requisite conditions are 

 present, the young proceeding from the division of the parent 

 pass into this state immediately after they are set free; their 

 soft investing membrane probably rendering them fitter for this 



* P. Ill tab. VII. fi^'. xvii. 



