36 ECHINODERMATA. 



result of experiments and observations become deeply affected by the 

 seasons : also because the learned have been induced to credit the pe- 

 riodical migratory habits of various animals, which are, perhaps, alto- 

 gether stationary, or nearly so, on the spot where they originated. 



This specimen extended somewhat as a misshapen pear two inches 

 in length, and nine lines through where thickest. It was universally in- 

 vested by a yellowish-brown shaggy coat hung loosely over it, with frag- 

 ments of weeds and shells also adhering to the surface. The covering, 

 like the coarse wool of a quadruped, relaxed into a multitude of papillae, 

 or, more correctly speaking, suckers, alternately stretching and contract- 

 ing, and ultimately affixing to the side of a glass vessel, where the speci- 

 men remained motionless for ten days. But the site proving unsuitable, 

 together with supervening vitiation of the element, rendered removal in- 

 dispensable, which was effected by whirling the vessel rapidly round, 

 and the animal was liberated safely, by the suckers gradually losing their 

 adhesion. Having affixed itself again in another vessel better adapted 

 for such a subject, it resumed its pristine form. Plate VIII. fig. 1. 



All the Holothuriae of this and the preceding paragraph when dis- 

 engaged, assume a globular, ovoidal, or spherical form, under which they 

 float amidst the waters, or are rolled on the bottom below. They are 

 contracted to various dimensions, and moulded into different shapes, 

 gradually changing as they find themselves in positions of security, fig. 2. 

 But there is a difference so extraordinary between the quiescent 

 and the active animal, that the experienced only those to whom no 

 alteration is new, are capable of declaring their identity previous to the 

 evolution of the parts. Who can anticipate that the purple, smooth, 

 and apparently lifeless mass which he leaves like an egg at twilight, shall 

 become a crescent, or a cylinder sometimes the length of his leg, ere the 

 break of dawn, unfolding a beautiful, luxuriant, arborescent apparatus 

 of many branches, which tranquilly sweeps through the water ? Hence 

 is it, perhaps, that older naturalists describe such creatures, beholding 

 them in the day, as motionless, and, although animated, differing but 

 little from plants. 



But let us pass, per saltum, from the beginning of December to the 



