24 AxXTIIOZOA IIYDROIDA. 



the polypes and their regeneration ; """ and it seems to me not 

 altogether unwarrantable to infer a like temporary existence 

 and revival in those of the Sertulariadse from a reflection on 

 the experiments of Mr. Lister, — incomplete certainly, but 

 which prove that, unfavourably situated, the polypes dis- 

 appear by a process of internal absorption,f and would pro- 

 bably have been renovated had fresh water been supplied, 

 as I have witnessed this result in similar experiments. On 

 Saturday, May 28th, 1837, a specimen of Laomedea gelati- 

 nosa was procured from the shore, and, after having ascertained 

 that the polypes were active and entire, it was placed in a 

 saucer of sea-water. Here it remained undisturbed until 

 Monday afternoon, when all the polypes had disappeared. 

 Some cells were empty or nearly so ; others were half-filled 

 with the wasted body of the polype, which had lost, however, 

 every vestige of the tentacula. The water had become putrid, 

 and the specimen was therefore removed to another vessel 

 with pure water, and again set aside. On examining it on the 

 Wednesday (June Lst), the cells were evidently filling again, 

 although no tentacula were visibly protruded ; but on the 

 afternoon of Friday (June Sd) every cell had its polype com- 

 plete, and displayed in the greatest perfection.^ Had these 

 singular facts been known to Linnseus, how eagerly and 

 effectively would he have impressed them into the support of 



* " The most singular circumstance attending the growth of tliis animal, and 

 which I discovered entirely by accident, remains to be mentioned. After I had 

 kept the clusters in a large bowl for two days, I observed the animals to droop and 

 look unhealthy. On the third day the heads were all thrown off, and lying on the 

 bottom of the vessel ; all the pink colouring matter was deposited in the form of a 

 cloud, and when it had stood quietly for two days, it became a very fine powder. 

 Thinking that the tubes were dead, I was going to throw them away, but I happened 

 to be under the necessity of quitting home for two days, and on my return I found a 

 thin transparent film being protruded from the top of every tube : I then changed the 

 water every day, and in three days' time every tube had a small body reproduced 

 upon it. The only difference that I can discover in the structure of the young from 

 the old heads, consists in the new ones wanting the small red papillce, and in the 

 absence of all colour in the animal."— Proceed Zool. Soc. No. 41, p. 55. 



t Phil. Trans. 1834, p. 374, 376. 



t See also Couch's Com. Fauna, iii. p. 2. — I have now ascertained that the heads 

 of Coryne pusilla, although apparently continuous with the apices of tlie branches, 

 are deciduous like those of the Tubularia;, and produced anew in favourable circum- 

 stances. 



