Observations on Stephanoceros EieJihornii, By T. B. Rosseter. 171 



it is able to live and propagate its species independently of the 

 cell. 



On another occasion I watched the development of a young 

 Stephanoceros from the moment of hatching, and am able to verify 

 the fact that the tentacles originate as buds, and unroll like the 

 fronds of ferns. After the lapse of about eleven hours from the 

 time of hatching, the upper portion of the young animal com- 

 menced to swell, and small buds began to be pushed upwards 

 much in the same way as the tentacles begin to show themselves 

 on the more advanced buds of Hydra. These buds were covered 

 with minute cilia, and when they had been pushed up a short 

 distance they began to gradually unfold (plate V. figs. 2 and 3) in 

 the same manner as one sees the fronds of ferns unfold. They 

 remained in this drooping state for two days, but on the third day 

 took the beautiful arched form of the adult. 



Ehrenberg was correct when he stated that Steplianoeeros 

 EieJihornii was viviparous, although at the time his ideas were con- 

 sidered erroneous. I have seen them give birth to young in this 

 way very frequently, and on one occasion Dr. English * watched 

 an individual under the same circumstances. The specimen that I 

 watched was, when I found it, thoroughly sunk into the cell. The 

 cell had not been retracted with the creature (fig. 1), but was 

 perfectly erect. The creature was as I thought in a dying state, 

 and nothing in the shape of food tempted it to come out of its cell. 

 The posterior portion of the body was very much enlarged, and hung 

 down like a bag. The tentacles seemed with the funnel to be 

 thrust into the body of the creature ; in fact, at times, it seemed 

 huddled in a heap. After a short time it revived a little, and 

 seemed inclined to elongate, but quicldy retreated again. With a 

 1 /2 in. and C eye-piece I saw the outlines of a young Steplianoeeros 

 in the pendulous portion, and later a slight opening in it through 

 which it began to protrude head first. As it gradually came out, 

 the posterior portion opened much wider, and the parent seemed to 

 strain itself to get rid of its burden. At length it seemed about to 

 do so, but the young one, as if fearful to trust itself from its mother, 

 withdrew, but soon to be expelled by a violent efi'ort on the part of 

 the latter. After floating about in the cell for a short time, it made 

 its escape in the usual way through the natui'al orifice. The 

 mother never recovered, but died in the cell about half an hour 

 afterwards. 



The fact of the parent dying might at first sight seem to 

 lead to the conclusion that this was not a true act of viviparousness, 

 but I have, as I have said above, witnessed several similar cases, but 

 not attended with the same fatal results to the parent. 



* Resident Medical Officer at St. Mary's College, Canterbury. 



N 2 



