OF THE SALPiE. 51 



latter mode of grouping is quite unintelligible and inex- 

 plicable under tlie hypothesis of M. Edwards. 



It occius to me that the regular grouping of indivi- 

 duals in Botrijllm, &c., bears the greatest resemblance 

 mth the catenation of the SalpcB, and may best be com- 

 pared with it ; and I consequently consider, until obser- 

 vation proves the contrary, this grouping to be a foetal 

 condition, and assume that the Botrylli are born in this 

 state of organic connexion. In accordance with this sup- 

 position, I am inclined to consider the sohtary Ascidice, 

 whose development into perfect animals has been so 

 beautifully shown by M. Edwards, to be the animals 

 which produce the aggregated ones, just as the solitary 

 SaljOiB bring forth Sal^a-chains. It may be sufficient to 

 have expressed this opinion, since observations are wanting 

 to enable our advancing fm^ther in this direction than to 

 a probable hypothesis. 



I now proceed to another class of the animal kingdom, 

 the Entozoa, with respect to some of which I can rely 

 upon observations which will serve to illustrate some of 

 their relations, which have been hitherto obscure. 



