20 ECHINODERMATA. 



markable animals, and by seeking frequent opportunities of observation, 

 the learned might have both avoided their own errors, and might have 

 corrected those of others. But doing so in their proper element was in- 

 dispensable. 



The following discussion shall be limited to my personal observations 

 on a few of the tribe, which have afforded me the 'best opportunities. 

 Many more indeed have come into my possession ; some of them fine 

 specimens. Yet they did not yield matter sufficient for commentary, 

 or were perfect enough for delineation. The distinctions of those se- 

 lected are so well marked that they stand far apart. 



Including the whole specimens of the various species that have been 

 obtained by me, they may be probably rated at one hundred and 

 sixty, of different size and age, within the period of thirty years. Yet 

 inconceivably few of that number, perhaps not a tenth or twelfth, were 

 entire, strong, free of mutilation, and fit for continued observation. 

 Among these was only one specimen of that I have named provisionally 

 the Scotica, one of the In/Kerens, and seven of the Phantnpus. All these 

 and others survived their captivity ; yet drawings were sometimes im- 

 practicable, and sometimes attained with the utmost difficulty of the rest. 



All Holothuriae dwell in the sea ; and it may be presumed that, 

 under certain modifications, they attain greater size in deeper water. In 

 most parts of Scotland they are extremely rare. 



In their native abodes these animals seem to affix themselves very 

 firmly below, to such substances as they can be dislodged from with great 

 difficulty, and very seldom with impunity. As the larger are the stronger, 

 it may be understood why so many are injured in recovery. It is only 

 some inconvenience that induces them to quit their hold, or they become 

 spontaneously erratic floating away on the waters also, when they may 

 be safely taken. 



The true nature of the Holothuria cannot be discovered in its dis- 

 tempered state, and most of the conditions admitting its capture renders 

 its subsequent preservation equally precarious. The wounds and lacera- 

 tions endured by forcible removal of specimens from the spot of adhesion 

 almost invariably occasion speedy death. Even the slightest abrasion of 



