130 - SIDNEY F. HARMER. 



one or two eggs, and one unmistakable ovicell was also 

 present ; no other development had taken place. 



This is the only colony in which I have obtained certain 

 evidence of the period at which the egg begins to develop ; but 

 taken in connection with the next described series of cases, 

 the conclusion may be drawn that the degeneration of the 

 fertile polypide normally takes place shortly after the polypide 

 has become functional. This is in accordance with the fact 

 that ovaries or eggs are not found in the older polypides of a 

 colony, indicating that they are in some way absorbed or 

 degenerate if development does not begin in them shortly 

 after their parent polypide has become mature. 



The occurrence of more than one polypide in the fertile 

 zooecium of Lichenopora is associated with the fact that 

 each of the ordinary zooecia of the young colonies also pos- 

 sesses a brown body and a polypide. This is not the case in 

 Tubulipora, in which there are normally no brown bodies 

 (in the species investigated) in the young colonies. It is not 

 impossible that this may have something to do with the season 

 at which my material was collected. My specimens were 

 obtained during March and April, a time when growth is 

 taking place with great energy, probably after a period of 

 winter rest. I have found brown bodies commonly in colonies 

 of Tubulipora obtained in Devonshire during the summer 

 months. It is not impossible that the excretory vesicles 

 which have been described above provide a means of eliminat- 

 ing excretory matters which would otherwise accumulate in 

 the stomachs, and induce the formation of brown bodies. 

 Whether this be the case or not, the entire absence of brown 

 bodies in a large proportion of the specimens of Tubulipora, 

 even in quite large colonies, is a fact in striking contrast with 

 the normal occurrence of brown bodies in the young zooecia of 

 Lichenopora. 



Evidence of the degeneration of a fertile polypide was 

 obtained in ten cases, four of which appear to belong to 

 T. plumosa and six to T. phalangea. The results of the 

 examination of these cases were quite concordant, all of them 



