HOLOTHURIA j:, 



Future observers may discover the genuine functions of them 



which are at present very doubtful. All the authors whose word* I 

 have in recolle. -timi. except the NeapolitAii professor, assign a tentacular 

 office, or what is equivalent to feeling in the larger animals, an their 

 nature, while he conjoins something respiratory along with it.* To 

 this, however, as will afterwards appear, there are certain relevant ob- 

 jection.-v N'e\erthele*, tin- Mj.imoM iif -.1 learned .-uitl iniluMrinus a na 

 turulit merits liiirli consideration. 



During '|iiiescence of the Holothuria, the tentacula occupy the nar- 

 row circumferential channels of the cylinder, which is retracted within 

 the c.-i\ityof the lody. Their display is extremely irregular, and is 



Hen so transient that it ma\ MM! '|iiite i-aprii-iiiii n<.r < eiilial : 



the necessities of the animal. A specimen obtained in June, flouted an 

 if tupjid with water. The tentacula sometimes protruded like a purple 

 plume, along with some part of the cylinder. But they were never seen 

 completely expanded until the subsequent March, that is, for nine 

 iii'iiiih-. This specimen afterwards displayed them occasionally during 

 the whole day in full vigour, an incident which occurs very rarely. 

 Another specimen procured in December, was not observed to display 

 the tentacula before the end of March. These two specimens sometimes 

 assumed the form of a horse-shoe, when the two ends, from the great 

 curvature of the body, came almost in contact. 



The destruction of any resisting prey is irreconcileable with the ex- 

 traordinary timidity of this creature. It is firmly rivet tod to the -put 

 of its selection by numerous suckers, which, in the present instance, 

 constitute the shaggy coat investing it. An adhesive faculty also at- 

 taches shells or fuci to the whole body, when coming in contact. All 

 tliis is spontaneous, but sooner than quit its hold by violence, the llolo 

 thuria will submit to the severest injuries, even to absolute destruction 

 Thence may be understood the difficulty of obtaining specimens entire 

 Were it bold and carnivorous, the same powerful adhesion mijiht enable 



* Drlle Chiait'i Obeervations were made on m tpecae* different from mine. After 

 describing the internal respiratory organs connected with the intestinal canal, be MJI, 

 " the tentacula are also the medium of the respiration of these admirable being*," $ 4. 



