36 



HARDWICKE'S SCIENCE-GOSSIP. 



the study of which has been most interesting. I 

 have been enabled to follow them through the entire 

 circle of their life, and I trust, with the aid of the 

 accompanying sketches, to render the same plain 

 and interesting to the readers of Science-Gossip. 



cell, and they increased by fission to over thirty 

 in number by the end of June. On the 23rd 

 of July I observed some of them were with- 

 drawing their spines. Having seen the same thing 

 performed by the A. Sol, and knowing that this 



— -n 



Fig:. 13. Actinnphrys Eic/ikornii ; J, food at the edge of body and spines 

 crossed ; B, contractile vesicles; C, vacuoles containing food and digestive 

 matter. 



Actinophrys Mchhornii differs very materially from 

 A. Sol. It is generally much larger when full- 

 grown, of a whiter colour, and more translucent. 



Fig. 15. Spines partly withdrawn; D, 

 irregular inner circle. 



indicated a change about to take 

 place, I became much interested in 

 them, and was very desirous of 

 witnessing what these changes would 

 lead to, being persuaded that they 

 had to do with the preservation and 

 propagation of their species ; and, as 

 the reproduction of these animals is 

 very imperfectly known, and little 

 understood, any light thrown on the 

 subject must be of interest. I had 

 seen what is termed " conjugation " 

 take place several times. The process is this': 

 two Actinophryes approach each other; their spines 

 first meet and cross each other; but. soon the 



\ i « / 



Fig. 14. A. Eichhomii (conjugation). 



Its spines are more numerous, more flexible, and of 

 greater length ; some of them are more than twice 

 the diameter of the body. In the beginning of last 

 May I had six of the A. Eichhomii in a glass 



Fig. 16. The transparent state: G, the pellucid mantle; 

 H, capsules or ves cle ; /, spermatozoa escaping from 

 the capsule. 



surfaces of the two bodies,' touch, and they slowly 

 become fused into one mass, first of an oblong form 

 (fig. 14), and finally into one large round Actinophrys 



