92 ECHINODEBMATA. 



Many of the animals which have been beautifully symmetrical when 

 entire, appear strangely distorted on absolute privation of some of their 

 perfect organs, and the irregular evolution of others. 



The aspect of individuals often alters very much, either superficially, 

 or in the distribution of the colours. Some undergo a great external 

 change with age. The whole tribe seems to abound in varieties, inso- 

 much that it is difficult to reconcile the observations and descriptions of 

 different naturalists. Perhaps the enumeration of species exceeds the 

 truth of Nature. 



The surface of the Star-fish presents many interesting, curious, and 

 beautiful patterns for imitation in the arts, and in great variety. Some- 

 times a singular arrangement of points and orifices sometimes a profu- 

 sion of organs in the semblance of luxuriant flowers. 



As the skin is penetrated by innumerable orifices, through which 

 certain processes rise at the will of the animal, the surface is subject to 

 continual alteration. Of two specimens of the Solaster, one may be the 

 brightest scarlet, studded with many white spots, and the other of the 

 darkest crimson, wholly of uniform colour. Of another species, indi- 

 viduals may appear yellow, purple, or red, speckled white. 



An important branch in the history of these creatures the mode 

 of their perpetuation, was long involved in mystery. The reproductive 

 energies of the tribe, the frequent and ready recovery of lost parts, were 

 well known to almost every one acquainted with the animal, or accus- 

 tomed to see it entire and mutilated. But the way in which they bred 

 could be told by none. This is a subject which seems to be involved in 

 greater obscurity in general, than any other in the history of living beings. 



In regard to those dwelling in the waters, our ignorance may origi- 

 nate from two sources ; first, the produce of the female parent, whatever 

 it is, may float away at first and disappear ; secondly, it may be de- 

 veloped into forms, which, bearing no resemblance, are never recognized 

 as kindred. 



In so far as I have observed, a quantity of roe is generated, chiefly 

 in spring, and advances to maturity in summer, which is differently dis- 

 posed in these animals, according to their different form. 



