HOLOTHURIA. 19 



tinct description, and the most imperfect representation, from the days 

 of Gesner in the sixteenth century, down to the present era ; for, un- 

 less in soUtary examples of a few of the more learned, an uninterrupted 

 series of errors has led tlie others astray. So completely has the sub- 

 ject been overlooked, that, although the etymology of the name Holo- 

 thuria may be conjectured, I know not any author who treats of its ori- 

 gin or derivation.* 



Besides the few auxiliaries of the sedulous student, the transient 

 observer is certainly exposed to delusion, from the utter dissimilarity of 

 the Holothuria in its active and passive state. No two animals, in ma- 

 turity, can be more unlike than this single creature is to itself. It is 

 wholly a simple bag, or partially a beautiful flower, or luxuriant arbo- 

 resence. 



An intimate knowledge of only the external form of the Holothuria, 

 is therefore absolutely dependent on patient preservation of living spe- 

 cimens, and the opportunities which they offer to us to study them. 



If these be favourable, the observer will not be slow in discovering 

 that the characteristic Echinodermata is of the most doubtful application, 

 and that none of the definitions hitherto proposed or adopted wUl dis- 

 tinguish the race intelligibly, because there is no common resemblance 

 sufficiently precise among all its members. At least that resemblance is 

 not yet explained. 



In several instances also we find several different Holothurife re- 

 cei\dng the same name from different authors, and the same Holothuria 

 distinguished by different names from the same author ; all tending to 

 aggravate the perplexities, besides urmecessarily multiplying the number 

 of species. Much of this, indeed, ensues from the difficulty of the sub- 

 ject. It is not an easy matter to satisfy each originating doubt by re- 

 sorting to the bottom of the sea for authority. All researches there are 

 liable to the most uncertain result. 



Nevertheless, it is possible that, by the personal study of these re- 



* Gesnerus, Icones Animalium, considers one species as motionless, others as differing 

 little from plants, p. 262. 



