1897.] Fresh Water Jelly Fish. 1033 
text has been found, and the sorrow that his many friends feel 
at his early removal, has, to me, this added regret—that he 
was not able to complete an investigation, which, not unnatu- 
rally, perhaps, I felt to be of so great importance; and that 
he cannot now share with us our great delight in witnessing 
the further development from Microhydra ryderi of a “ medusi- 
form adult stage.” 
As may be seen by a comparison of the papers above 
named, all of them preliminary and incomplete,—there are 
obvious points of resemblance as well as of difference between 
these minute organisms that appeared, almost simultaneously, 
at geographical points so widely distant. The supposition that 
the form observed by Mr. Bourne is the earlier condition of 
Limnocodium is, of course, greatly strengthened by my actual 
observation of the budding and separation of free-swimming 
Medusee from M. ryderi.' 
We read that the specimens of Limnocodium often, perhaps 
generally, disappeared from the tanks about the end of June 
or July? It is greatly to be regretted that the glass jars con- 
taining my species were not carefully examined throughout 
June and July of the present year, during which period there 
may have been a larger production of maturing jelly fish. On 
the first day of August, however, my attention was arrested by 
the spasinodic contraction of an evident Medusa in the above- 
mentioned jar, and, during several following days, Prof. E. P. 
Cheyney and myself, on frequent occasions, watched the swell- 
ing buds upon colonies of Microhydra that had attached them- 
selves to the glass. We witnessed the spreading of the disc, dis- 
closing, from the first, eight marginal tentacles, a well-defined 
velum, whose aperture was from one-third to one-fourth the 
diameter of the disc, and a manubrium depending, about one- 
half the height (or depth) of the bell. Violent pulsating 
spasms finally resulted in an entire separation from the hy- 
droid and the free life of a roving medusa. I kept no record 
of numbers, but it is believed that from twelve to twenty were 
seen. 
1 This alternation and progression may have been seen, later, in England, but 
I shall have to plead ignorance of the fact. 
2 In one case “swarms” are reported Aug. 18, 1882, at Kew Gardens. 
