258 ZOOPHYTES. 



The surface of the Alcyonium is covered by a multitude of hydra, 

 sometimes shewing themselves readily ; but in regard to this specimen, 

 so few ever appeared, and then so transiently, that it was impossible to 

 discover their peculiarities. 



Nevertheless I preserved it, in hopes of seeing some of the old co- 

 lony, or, should these have died, some of the new when regenerated ; and, 

 with this view, slices were taken at intervals of time from the surface. 



No hydra; were seen during six months, including the whole winter ; 

 the last appeared on the 12th of December. 



Gemmules in the substance of the Alcyonium continued in abun- 

 dance. Those obtained on January 1 6, are represented Plate XVI. figs. 2, 3 ; 

 others procured in the same manner from slices on the 30th of that month, 

 figs. 4, 5 ; and those on March 12, fig. 6. 



Great disparity of size and form were exhibited by the whole, and 

 much variety in their motions : but I cannot say they were such as to 

 constitute any notable distinction from what was exposed by those of the 

 earliest period. They were alike active and vigorous, always ready to 

 escape from the slices, but undergoing no metamorphosis whatever. 



Their number apparently diminishes with the advance of spring. I 

 found them until the first of May ; but the last experiment produced only 

 a single gemmule. 



Many attempts for their permanent preservation proved abortive. 



Thus the history of these creatures remains very obscure, and the 

 purpose of their existence equally problematical. 



I was not sensible of their production naturally during all the time 

 that the Alcyonium was preserved. Bodies so minute generally attract 

 notice on becoming stationary, and developing into different forms. None 

 did so here. 



It is far from improbable that they are the elements of regenerated 

 hydra; clothing the surface of the product. Being somewhat sunk in the 

 flesh, we have no means of discovering the progress of their metamorphosis. 



The substance of the Alcyonium is obscurely and irregularly cellular. 

 It is interspersed with numerous brown specks, which may be the remains 

 of decaying hydrae. 



