420 REPORT— 18653. 
is the same absence of evidence as to the origin of the earliest observed 
stage. 
Now, so far from the three cases just detailed affording evidence of direct 
development from the egg, I believe that the evidence is altogether on the 
other side, and that we are more justified in regarding the earliest stage ob- 
served in each case as the immediate result of an act of gemmation, if not 
from a polypoid trophosome, at least from a previously existing medusa. 
The following three sets of observations made in this same family of the 
Aiginide afford a clue to the true interpretation of the above-mentioned 
cases. 
Gegenbaur* observed buds produced from the inner surface of the stomach- 
walls of a medusa, which he named at the time Cunina prolifera, though he 
afterwards referred it to the genus dgineta, Gegenb.t He traced the deve- — 
lopment of these buds into a form closely resembling that of the parent 
medusa; they then become free in the surrounding water; and he does not 
seem to have followed them in their further progress. 
Kefferstein and Ehlerst also observed buds proceed from the stomach- 
walls of a species of Ayineta (Ai. gemmifera, Keff. & Ehl.). They traced 
them through their development up to a point when they found them to 
acquire nearly the form of the parent medusa. 
These two cases aré thus instances of gemmation followed by metamor- 
phosis, and render it probable that the developmental series observed by 
Johannes Miiller, by Kélliker, and by M°Crady had their origin in a bud 
rather than in an ovum. 
We have, however, a third case of especial interest in this inquiry, and 
one which seems to throw considerable light on the curious observation of 
Kolliker above mentioned, in which a brood of 16-tentacled meduse was 
found in the stomach of a 10-tentacled form. The case to which I allude is 
recorded by Fritz Miiller§, who describes the formation of ciliated buds from 
the internal surface of the stomach in an 8-tentacled Cunina, which he names 
CO. Kollikeri, Fr. Mill. He traced these buds through various stages until he 
saw them detach themselves, and swim free in the cavity of the stomach. 
Here they underwent further development, which he continued to observe 
until he saw them transformed into true Cunine, differing, however, from 
the parent by the fact of their having twelve tentacles and twelve stomach- 
pouches instead of eight, the number characterizing the medusa which gave 
origin to them. Beyond this point Miiller lost sight of them, and we are 
accordingly ignorant of their further changes and ultimate destination. 
This case renders it highly probable that the 16-tentacled Stenogasters 
observed by Kélliker in the stomach of a 10-tentacled Eurystoma originated 
in an act of gemmation from the Zurystoma. M°Crady’s case, however, where 
young Cwnine were found in the umbrella-cavity of an Oceanidan, would 
seem to be one of true parasitism, the contained forms being here evidently 
in no way genetically related to the containing one. 
The whole of the observations now detailed, beginning with that of Joh. 
Miiller on dsyinopsis, afford a valuable contribution to our knowledge of the 
life-history of the very aberrant group of medusze which constitute the family 
of the Aiyinide. Some of them afford direct proof that in certain cases the 
meduse of this family give origin to buds which detach themselves from the 
parent at a very early period of their existence and in a very imperfect con- 
dition, and then pass through a series of metamorphoses before arriving at 
* Generationswechsel, p. 56. + Zeit. f. wissen. Zool. 1857, p. 262. 
+ Zoclogische Beitraige in Neapel u. Messina, 1861. § Wiegmann’s Archiv, 1861. 
