340 1'^^ Philippine Journal of Science 1913 



signs of degeneration. Furthermore, none of these terminal 

 hydranths bear gonophores, although they are the longest and 

 oldest in the colony, thus making it probable that we have in E. 

 gnffini a distribution of function, at least, if not two distinct 

 types of zooids. Whether we have here two types of individuals, 

 nutritive and reproductive, or whether this condition is simply 

 due to the greater age of the terminal hydranths, or whether, as 

 seems most probable, the conditions under discussion are due 

 both to a distribution of function and to the effect of age, cannot 

 be fully determined until more and, perhaps, living material is 

 available. 



The shortening of the gonophore-bearing female hydranths 

 may be attributed to the absorption of their protoplasm by the 

 gonophores as suggested by Hargitt (Congdon, '06) in the case 

 of the spadix tubes of E. ramosum, and it may be considered. 

 as a stage in the atrophy of the fertile hydranth which is very 

 common in this as in other species of the genus. The normal 

 hydranth of the female colony seems to be similar to that of the 

 male colony, that is, long and slender, yet when gonophores are 

 present on a hydranth it is always found to be shortened. This 

 shortening is more marked in hydranths bearing mature gono- 

 phores and less so in those where gonophores are few or just 

 appearing ; and it is followed by the atrophy of the hydranth and 

 the depositing of some of the ova on the pedicel. 



This atrophy is found in E. griffini only in the sexually mature 

 female hydranth, not in the male as is the case in many species 

 of Eudendrium. If the shortening of the fertile hydranth and 

 its ultimate atrophy, so characteristic of the genus Eudendrium, 

 is due, as seems probable, to the appropriation of its food supply 

 and tissues to provide for the rapid growth of the gonophores 

 and ova, we would expect to find the extent of the process varying 

 in different sexes of the same species or in the same sex of 

 different species in proportion to the number of gonophores borne 

 by a single hydranth. That is, where many gonophores are 

 borne on a single hydranth, we would expect to find a great 

 shrinkage of the hydranth and its early and complete atrophy; 

 and, conversely, where few gonophores are borne on a hydranth, 

 we would expect to find only a slight shortening of the hydranth 

 and little if any atrophy. The female hydranths of almost all 

 described species, as well as the male hydranths of many species, 

 such as E. ramosum, E. racemosum, and E. capillare, are ex- 

 amples of the first condition. Here we have the production of 

 many gonophores on a single hydranth accompanied by atrophy. 



