MISCELLANEOUS. 55 



lar exhaustion of the vigour of the organs attends their ripening, as well 

 as in the nature of their contents. 



On the upper side of the large volute of the shell above referred to, 

 with the snowy fleece, the decay of many hydras exposed a number of yel- 

 low corpuscula, close to the epidermis, in the end of October. The sub- 

 ject was carefully preserved, but nothing resulted. 



Sometimes, in the months of June or July, part of the surface of a 

 shell, still bearing a colony, appears yellowish, while the reason is not im- 

 mediately obvious. But it is found to be from the accumulation of a 

 multitude of yellow spherules. 



I endeavoured to slice a portion of the epidermis off such a shell, 

 whereby some of the hydra were separated ; having been rent or cut 

 asunder near the root of the stalk. The upper part of the severed stalk 

 now proved to be surrounded by clusters, composed of various numbers of 

 yellow vesicles, apparently compressing the head, as in the Tubularia 

 ramea. The head also, as seen there, seemed verging to decay. These 

 vesicles were in different stages of maturity. Some of them evidently 

 included one, two, or even four embryonic corpuscula, each in its own 

 compartment. — Figs. 4, 5. A group of spherules, in their integuments, is 

 represented fig. 6. 



In a few days, many of the vesicles, figs. 4, 5, had discharged then- 

 contents in a watch-glass, as vivid yellow globules. Almost all were per- 

 fect spheres, and such as I should have rather expected would have pro- 

 duced planulae. Another quantity, fig. 7, was obtained at a later period of 

 the year. But, unfortunately, the whole perished and decomposed on both 

 occasions. No sensible difference of the latter from the former could be 

 recognised. The form was alike perfect, the colour equally vivid, with 

 somewhat more consistence apparently. 



On still another occasion, I suspended a shell in a vessel of sea-water, 

 containing a watch-glass at the bottom. In four days, at least 150 yel- 

 lowish globules had fallen into it, besides 50 or 00 on the bottom of the 

 vessel ; and a few were swimming in the water, fig. 8. Nothing illus- 

 trative resulted. Several much larger globules remained on the rough 

 surface of the shell. 



