HOLOTPIURIA. 49 



there is little interesting here compared with some very remarkable 

 physiological anomalies presented by this animal. 



The aspect of the specimen, Plate VIII. fig. 1, — its resemblance to 

 an elongated pear, with a villous coating when first procured, will be 

 recollected. Between a fortnight and three weeks from its acquisition, 

 the tentacular apparatus, imperfectly expanded, protruded for the first 

 time along with the cylinder, from the upper part of the body. Next 

 day a large proportion of the intestine, descending from it, came 

 forth also ; and the animal having crawled up the side of the vessel, 

 allowed most of the investing shelly fragments to fall off. No external 

 symptoms of suffering were demonstrated ; yet it was reasonable to 

 apprehend that these, and some other marks of weakness, were the pre- 

 lude of decay : and this apprehension Avas aggravated by the separation 

 of all the organs protruded from the body, on emptying the vessel for 

 replenishment. Still, the Holothuria seemed no more affected now than 

 before. Assuming an oblique position, it rose on the side up to the very 

 edge of the water. But, instead of ascending higher, it remained affixed 

 immoveably to the glass, for the water is never quitted by this species. 



Following the history of the detached organs : — the tentacula rose 

 from the extruded mass like crimson tufts, and the whole testified signs 

 of vitality for several days. When removed to another vessel, death 

 and decomposition ensued, as might have been expected. 



But a premonition of no slight utility was afforded here, evincing 

 the liability of even the most practised naturaUst to error. MuUer, 

 whose name is justly enrolled with those of the highest order, deluded 

 by certain fallacies, on beholding the upper portion of such a mass, deter- 

 mined it to be a perfect animal, which he distinguished as the Holothuria 

 penicillus. Repeated opportunity and patient investigation can alone 

 discover the truth amidst ambiguities. The Holothuria penicillus, to 

 which a place was long assig-ned as a distinct species, must be therefore 

 now expunged from the Systema Naturce. 



So many extraordinary instances of complete renovation of defec- 

 tive organs had been witnessed in the course of years, and of such as 

 were endowed with all the faculties of those they replaced, that, after 



G 



