ACTINIA. 207 



as larger and denser substances, are found in the distended tentacula, one 

 or more in each, the corpuscula in motion, the others at rest. 



The latter are so many young in different stages, some apparently so 

 mature as to be ready for production, and I have no doubt that they would 

 be produced were it not from some singular faculty of retention in the 

 parent. They are frequently withdrawn for many months to come ; or 

 they are returned, occasionally to the tentacula, or shifted to a different 

 position. 



Meanwhile, as these internal corpuscula continue in view, they pur- 

 sue an irregular course among the liquid contents of the tentaculum, 

 wherein they bear no inconsiderable resemblance to the Animalcula info 

 soria, only, surpassing the size of the largest. 



At first sight the observer will be disposed to class the animals before 

 him with the numerous parasites infesting so many living creatures, and 

 he may naturally enough look for them in vessels containing Actinia?. 

 But his search will be vain, for, unless on the rarest occasions, thev are 

 never to be seen at large. 



Instead of awaiting so uncertain an event, a more ready expedient 

 can be resorted to in amputating the gravid tentacula, for the sake of ob- 

 taining their contents. 



I was originally inclined, as others would be, to view the corpuscula 

 as parasites, or Animalcula infusoria, which, by some means, had obtained 

 a lodgement in the Actinia. Thus, while at least seven different tentacula 

 contained embryo Actiniae, so far developed as to bear a general resemblance 

 to the parent, I observed the active corpuscula single in orle tentaculum, 

 and two or three in others. Single corpuscula were then found in several 

 more, and some tentacula contained both corpuscula and embryos. 



Neither of the two being confined to any season of the year, allows 

 greater scope for experiment. Therefore, having inspected a distended 

 tentaculum, towards the end of October, I severed it from the Actinia 

 with sharp scissors, receiving itself and its contents in a watch-glass. 

 Scarcely had it fallen there, when a large embryo was discharged, and im- 

 mediately afterwards, two active corpuscula also escaped from the section. 

 The former lay still. It consisted chiefly of several obtuse prominences. 



