ALCYONELLA. Ill 



ther without or within, converted to a covering on retreat, and relaxed as a 

 cylinder on the greatest extension from the polyparium. 



When originally collected, the hydrse of all the specimens were replete 

 with dark matter, the substance or residue of the mud suspended among 

 the water of the pond, which was soon discharged so profusely in pellets, 

 as to cover the bottom of the vessels containing the subjects. 



While the hydrse of the specimen above described remained quite vigor- 

 ous, ova were liberated in the beginning of October, but the hydroe having 

 ceased to protrude about the 14th, progressive decay of the common mass 

 favoured the escape of hundreds to float at the surface of the water, fig. 3. 

 Their numbers continued augmenting to a great multitude until the 7th of 

 November, when nearly the whole investing substance had disappeared : 

 and the branch, of which very little was originally exposed, remained 

 totally bare on the 30th. 



Now, many of the ova were discovered to be imbedded in its surface, 

 in rows of eight, ten, or twelve together, fig. 4. Thus it is quite evident 

 that the ova were generated below. 



Most unfortunately supervening incidents interrupted the course of 

 observation, preventing also the preservation of the numerous ova, from 

 which I had anticipated much interesting information ; so that the history 

 of the subject remained altogether incomplete. 



The naturalist must submit to many disappointments and contrarieties, 

 as will be but too plainly proved by the sequel. 



I had left much undone ; but desirous of resuming investigation of a 

 subject still promising satisfaction, I resorted to the same spot in the 

 county of Berwick, between fifty and sixty miles from my usual residence, 

 during the proper season in 1833. 



Not a single specimen could be found ; nor was I more fortunate on 

 repeating my visit during the succeeding year. 



I know very well that natural products previously in the greatest 

 vigour and profusion, sometimes suddenly disappear ; that others before 

 unnoticed, originate unexpectedly, as if substituted in their place. Like- 

 wise, it so happens, that subjects thus disappearing, sometimes return to 

 resume the former position, as it were, which their genera or species oc- 



