578 THE MICROSCOPE. 



stitutes one of the chief points of interest in the organiza- 

 tion of TomoptcTisr 



^ot solely in this class, but in that of the Annelida 

 generally, does much interest attach to the developmental 

 period. Most of them come forth from the ^g^ in a con- 

 dition so closely resembling the cililated gemmules of 

 polypes, that competent observers have been known to 

 mistake them for animals of a lower class ; fortunately a 

 few hours' careful watching is sufficient to dispel the 

 illusory belief, and the embryonic globular sha^^eless 

 mass is seen soon to change its form ; segmentation takes 

 place, and the various internal organs become more and 

 more developed ; eye spots appear, and the young animal 

 assumes the likeness of its parent. 



The Actinotrocha, even in tbe adult state, in many parti- 

 culars resembles the "bipinnarian larva of the star-fish." 

 Its long body is surmounted by a head, or mouth, around 

 which is placed a number of ciliated ventacula : they are 

 not only employed for feeding purposes, but also for 

 enabling it to swim about ; and in this particular, accord- 

 ing to Dr. A. Schneider and other competent authorities, 

 it is quite remarkable.^ Dr. Carpenter tells us that he 

 has captured these free-swimming Annelids among other 

 marine, animals by the careful use of the " stick-net." 



,.t) See Ann. Nat. Hist. vol. ix. 1862, p. 4S6. 



