468 Mr Gardiner, Notes on Variation, 



form in the British Museum 42 mm. in length. If the corallites 

 continue to live, surely this should be exceeded in size from its 

 locality. At the same time it is likely that in other places with 

 less or more favourable environmental conditions the maximum 

 may be above or below this. Thus in the Maldives Mr Forster 

 Cooper and I dredged 8 dead forms, which averaged about 38 mm. 

 (judging from two of the less decayed specimens brought home), 

 the largest living form being 40 mm. 



In the smaller specimens the replacement of the escaped ova 

 by fresh ova is quite clear. Occasionally before an egg escapes, 

 the young ova are to be seen lying between the ovary and the 

 mesenterial filament ready to take its place 1 , Indeed at no time 

 is there a dearth or vacuity in the ovaries, whereas in the oldest 

 forms the ova are separated from one another, and there are no 

 signs of fresh ova being produced nor of the gaps being otherwise 

 filled up. 



A somewhat similar phenomenon to the above is shown by 

 a colonial coral, which I originally described from South Pacific 

 specimens under the name of Coenopsammia willeyi 2 . This 

 coral is common in the Maldives, seated on the under sides of 

 stones of the boulder zone. All the separate polyps of a colony 

 are of the same sex, male or female ; of protandry I have seen 

 no suggestion. Further, all the separate colonies obtained by 

 Dr Willey at Sandal Bay, Lifu, were of the same sex. Two 

 colonies found at Minikoi in July, 1899, were both female, as 

 were also seven collected at Hulule, Male Atoll, in January, 1900, 

 on the same day, hence probably from a restricted area. Other 

 colonies I have not examined, as two or more areas are or may be 

 mixed together in my collecting jars. 



In addition the genital organs of the polyps of Coenopsammia 

 willeyi in each of the above three collections are in the same state 

 as those of other polyps of the same species from their own area. 

 Thus in the Sandal Bay specimens the polyps were all females 

 with ova separated from one another, but yet fairly regularly 

 arranged. The ova are less regular in the Minikoi colonies, some 

 having dropped out and not been replaced. In the Hulule polyps 

 some of the ova touch one another, and are flattened on their 



1 Although I have examined a large number of specimens of Madreporaria of 

 all kinds, I have not been able to satisfy myself as to the origin of the generative 

 cells. The appearance in Flabellum suggests that tbey arise at the bases of the 

 mesenterial filaments, and thence wander to their ultimate position. This, how- 

 ever, is not confirmed in other species, and the question requires further examina- 

 tion. It is interesting to observe that, should the generative cells be derived from 

 the epithelium of the filaments, they would be ectodermic in their primary origin. 

 For a consideration of the body layers in the Actinozoa vide " On the Anatomy of a 

 supposed new species of Coenopsammia from Lifu," Willey's Zoological Results, 

 Pt. iv., p. 374—5 (1899). 



2 Willey's Zoological Results, Pt. iv., pp. 357-380 (1899). 



