Propagation amoiig the Lower Animals. 153 



shape are visibly detaching themselves from the circumfe- 

 rence. Some resemble solid prisms ; others approach a long, 

 oval, or other figure ; next, the margin seems contracting with^ 

 in a narrower circuit, while the separating fragment either re- 

 mains stationary or recedes from it. A connecting ligament 

 now appears between them, which gradually attenuates until 

 complete separation ensues. 



Still the fragment is a shapeless mass, but the subsequent 

 evolution of tentacula and its more symmetrical form, prove its 

 identity with the nature of the parent. By a number of frag- 

 ments detaching thus, in the course of a season, the parent is so 

 completely mutilated that it can be scarcely recognised as the 

 same animal. 



The attenuating ligament is somewhat above the substance 

 sustaining the actinia; it extends from two to eight or nine 

 lines, is free of adhesion below, and waves with the motion of the 

 water ; but it is too opaque to expose the circulation of a fluid, 

 if there be any, between the parent and the embryo actinia 

 before their connection is dissolved. 



II. Mcidi a papilla. — In the middle of summer, I observed 

 a minute animal among a quantity of marine collections, 

 wherein the Flustra carbasea formed the principal j)art. It 

 narrowly resembled a pin, such as is used in apparel, extended 

 about a line, and was of a reddish colour. A rude sketch ha- 

 ving been taken, it suddenly disappeared ; but I named it spi- 

 nula for the purpose of recognition. 



Exactly five years afterwards it occurred again on the same 

 day of the month, the 19th of July, under similar circumstances. 

 I was inclined to refer it to the globular corpuscula of the 

 Flustra carbasea as now exhibiting a very peculiar and unusual 

 aspect, modified, perhaps, at a certain season, or from some un- 

 known cause. 



Being in greater numbers, and under more favourable con- 

 ditions, I could follow its progress better. 



This creature bears considerable resemblance to a tadpole. 

 The tail is three or four times as long as the body or head ; 

 the surface uniform, void of external organs, the whole of sohd 

 consistence. It swims with much activity, chiefly by the ac- 

 tion of the tail, which is very flexible. (Fig. 1.) 



