AUTHOR S ABSTBACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, APRIL 20 



GERM CELLS OF COELENTERATES 



V. EUDENDRIUM RAMOSUM 



GEORGE T. HARGITT 



From the Zoological Laboratory, of Syracuse University 



NINETEEN FIGURES 



1. INTRODUCTION 



In this series of studies forms have been considered which 

 showed some differences in origin, growth, and ripening of the 

 germ cells, or which were taken as types of certain taxonomic 

 groups. It has been found that the different types of coelen- 

 terates do not necessarily show distinctions with respect to their 

 germ cells, but may, on the contrary, be essentially alike. The 

 study of Eudendrium was undertaken, not as a type of some 

 morphological group, but because of certain obvious, though more 

 or less superficial, peculiarities in the history of its germ cells, 

 and in particular with the egg cells. 



Whatever may have been found to be the ultimate method and 

 place of origin of the egg cells in most of the forms studied, a 

 cursory examination would usually show the egg cells to be first 

 observable in the reproductive bodies, whether they were gono- 

 phores or medusae. In Eudendrium this is not the case. No 

 doubt most zoologists who have examined this hydroid, or have 

 made use of it for class work, have noted the presence of egg 

 cell§ in the stem or branches, even when there were no reproduc- 

 ive bodies in that neighborhood. Such a condition is a com- 

 mon and rather striking feature of Eudendrium and might indi- 

 cate some peculiarity of the germ-cell history. It is also true 

 that the history of the egg cells in Eudendrium has been discussed 

 rather widely and certain phylogenetic implications made which 

 have considerable theoretical importance. These considerations 

 have led to a new study of the germ cells of this form, with a 

 brief review of the work previously done. 



1 



JOURNAL OF MORPHOLOGY, VOL. 31, NO. 1 

 JUNE, 1918 



