HOLOTHURIA. 85 



I say nothing definite, however, of such foreign products, consider- 

 ing it enough to deal with those which ai'e more famihar. 



NaturaUsts apparently entertain very vagaie opinions on the true 

 nature of the Holothuria, and of its proper position in the S^.sfcma 

 Naturce. But in fact it has been seen very rarely by any of the learned 

 devoting themselves to the study of the lower tribes, nor do I firmly be- 

 lieve ever in perfection. It may be questioned whether a specimen 

 was before Liunseus. MuUer certainly had several, and of these, such as 

 they were, he has preserved figures, but all must have been more or less 

 injured or contracted. I do not think any one could be completely de- 

 veloped, and displaying its external organs. M. de Blainville, whose ob- 

 servations prove him a naturalist of distinguished quality, may have had 

 several. Yet none could be in full vigour from his own account. Pro- 

 fessor Delle Chiaie undoubtedly had these creatures in great profusion. 

 Had they been entire, and vigorous, and treated suitably, how could 

 they have been considered different when actually the same ; or identified 

 for the same when actually different. The figures presented shew that 

 none were living. Among the most modern naturalists, however, Pro- 

 fessor Edward Forbes had opportunities of inspecting different species 

 while alive. I could specify only one or two other authors, belonging 

 either to the continent of Europe or to Great Britain, of whom I can say 

 the same. 



The facts hitherto obtained in the history of the Holothuria, afford 

 but few conclusions regarding its nature, compared with the tedious de- 

 tail of the preceding pages. Nevertheless, some will be found of such 

 interest, and so well established, as to encourage the farther research of 

 the curious. 



I. — The Holothuria does not appear to be aUied to any other genus of 

 animals. It is neither preceded nor followed by any one in immediate 

 approximation : Nor does any relation subsist, as some naturaUsts ad- 

 vance, between the Holothuria, Actinia, and Ascidia. Both the latter 

 seem to be far removed, and all are distinctly separated from each other. 



II. — The external integument is a capacious sac, containing the 

 viscera, the respiratory apparatus, and the ovarium, wherein also the 



