118 ZOOPHYTES. 



On the 26th of April, the ova of this Alcyonella began to sunder, 

 for giving exit to the embryo ; but it was ascertained from those protrud- 

 ing on the 13th of May, that they required at least 189 days for coming 

 to maturity. 



Few precautions but those which may not readily occur, will aid the 

 means of solving the problem. The gravity of the Alcyonella retains it at 

 the bottom of the water wherein it is immersed. But the ova, as liberated by 

 decay, generally rising to the surface, are attracted to the side of the vessel 

 by the peculiar curve formed there by the water, as previously alluded to, 

 and would remain dry on its evaporation. But should the phials or vessels 

 containing ova be inverted at first for a short time, some will adhere be- 

 low, that is, about the sides which were near the original surface. On beimr 

 reversed to restore their natural and wonted position, the same ova are 

 now under the surface. Moderate replenishment at intervals of time to 

 counteract the progress of evaporation, will preserve them in a sufficiently 

 humid state to prevent sterility. 



The naturalist must await very patiently the lapse of a long time, not 

 to defeat his own purpose. 



The native site of the Alcyonella thus occurring in the pond during 

 1837, was evidently wood. No specimens were found on the leaves of 

 trees, unless on those accidentally in contact with the wood became over- 

 spread by the advancing stratum. But almost every portion of wood, 

 which had lain there apparently for a considerable time, was invested less 

 or more : and after all that could be observed were collected, still other 

 portions came in view, being dislodged most probably by the diving of swans 

 kept in the pond. 



In further prosecuting the history of this subject, I detached a large 

 portion of bark on September 9. 1837, which was previously loosened from 

 a fir post standing in the pond. Its superficial area equalling 30 or 40 

 square inches, was almost completely invested by the Alcyonella, which in 

 some places had an indefinite ramified appearance, but too faint to be re- 

 cognised as a distinct character. I sunk it again, secured by a cord, in the 

 pond, so as to be kept fresh and accessible until I should quit the country, 



