On the Reproduction of a Medusa. 



133 



Arts and Manufactures, 1856, 3 vols. ; Agriculture, 1856, 1 vol. — From 

 the United States Patent Office. Smithsonian Report for 1857 ; Defence 

 of Dr Gould by the Council of the Dudley Observatory, Albany, 1858. 

 — From the Smithsonian Institution, U.S.A. Reply to Statement of the 

 Trustees of the Dudley Observatory. By B. A. Gould, M.D. Albany, 

 1859.— From the Author. 



Memorial to Government on behalf of the Livingstone Expedition. 

 Mr Andrew Murray reported that in accordance with the resolution of 

 a previous meeting, a memorial had been drawn up and forwarded to the 

 Chancellor of the Exchequer, praying that immediate assistance be granted 

 to the exploring expedition in Africa under the command of Dr Living- 

 stone ; and he was glad to state that the assistance required had since 

 been granted by the Government. 



The Communications read were as follows : — * 



I. On the Reproduction of a Medusa, belonging to the genus Lizzia. By 

 Professor Edward Claparede, Geneva. Communicated by Dr T. 

 Strethill Wright. 



M. Claparede stated that he had captured, in September last, in Lam" 

 lash Bay, a number of floating eggs. On examining these eggs he found 

 in each a true medusa, with four radiating gastrovascular canals, an d 

 eight tentacles — four short and four long, the long ones corresponding to 

 the radiating canals. A careful search was rewarded by the discovery 

 of the animal which had produced these eggs, a twelve tentacled medusa 

 of the genus Lizzia ; the bulbs, which in the embryo gave rise to the 

 longer tentacles, being in the adult each furnished with two of these ap- 

 pendages. The peduncle was laden with eggs ; of these eggs some ex- 

 hibited a germinal vesicle and spot, others well-developed medusae, but in 

 none was the stage of segmentation of the yolk observed. The question 

 was, whether the bodies in question were eggs or buds ? It was true that 

 no males of this form of Lizzia were found. But the males might be 

 more rare than the females, or, as Dr Strethill Wright had observed in 

 one case, might have a form different from that of the female. The 

 structure of the bodies was that of true eggs. The canals of the medusas 

 which they contained had no communication with those of the parent, 

 differing in this respect from the canals of the budding medusas of 

 Sarsia. The buds of Sarsia, moreover, did not exhibit the germinal 

 vesicle and spot. The author stated that the reproduction of medusas, 

 without the occurrence of a fixed hydroid stage, had been observed by 

 Gegenbaur and Krohn, but in these cases the embroyos had to undergo 

 important alterations in form before presenting the characters of the 

 parent. M. Claparede considered it possible that reproduction in Lizzia 

 might also take place with the intervention of the pianuloid and hydroid 

 stages. 



Mr A. Murray congratulated the Society on its good fortune in having 

 commenced a correspondence with so distinguished a naturalist as M. 

 Claparede; and proposed that the thanks of the Society should be trans- 

 mitted to him for his important communication, which was unanimously 

 agreed to. 



Dr Strethill Wright considered M. Claparede's paper of the highest 

 importance. Its author, it was true, had not traced the gradual develop- 

 ment of the ovum into a medusa, nor had he seen the segmentation of the 

 vitellus, but Dr Wright had convinced himself that in a majority of 



VOL. II. 



