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NOTES ON ANEMONES FBOM THE MILLPOET 

 MAKINE BIOLOGICAL STATION. 



By Eichard Elmhirst, F.L.S. 



It is well known that "increase by spontaneous fission,-" is 

 an occasional means of reproduction in Anemones (vide Gosse, 

 ' History of British Sea- Anemones,' 1860, p. xxi.). In a paper, 

 " Eegeneration and Non- sexual Eeproduction in Sagartia davisi " 

 (Univ. of California Publications; Zoology, vol. i., 1904), H. B. 

 Torrey and J. E. Mery describe the details of fission, and give a 

 useful bibliography of the subject. From many recorded cases 

 it appears that dividing individuals usually complete their 

 division in a few days or weeks ; this is especially the case in 

 Anthea. On the other hand, however, I have seen cases of 

 " double " Actinolobas, which showed no change during a period 

 of several months; it may be, of course, that when "double" 

 specimens are brought into captivity some change in their 

 environment may arrest the normal course of their division. 



Actinia. 



In 1911 I found an A. equina with two complete discs, 

 mouths, and sets of tentacles. After nearly four years in 

 captivity there is no change in the form of this individual. In 

 January, 19.13, I found a second A. equina, with two almost 

 complete discs, &c, apparently in course of division. This 

 specimen was isolated in captivity. In March and April it 

 produced a few normal young ; by May all trace of division had 

 disappeared, and the specimen was apparently normal; for a 

 few days an indentation across the base suggested that aboral- 

 oral fission was about to take place. This did not happen, and 

 the specimen is now (December, 1914) apparently normal. 

 Normal young were extruded in the spring of 1914. 



Five years ago I put a normal A. equina into a well-lit glass- 



