AUTHOR S ABSTRACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE AUGUST 18. 



NOTE ON THE STRUCTURE OF THE MAXILLARY 

 GLAND OF CYPRIDINA HILGENDORFII 



NAOHIDE YATSU 



Zoological Institute, Tokyo Imperial University, Japan 



FOUR FIGURES 



While at Misaki in the summer of 1900 I undertook, at the 

 suggestion of Professor Watase, a study on the ostracods with 

 especial reference to the cytology of the luminous glands. In 

 the winter of 1900-1901 quite a number of specimens were cut 

 into sections and several sketches were made. But my going to 

 America obliged me to suspend the work. Last summer ('16) 

 Dr. Harvey of Princeton University came over to Japan and 

 carried out at the Misaki Biological Station biochemical experi- 

 ments upon the luminous substance formed in the maxillary 

 gland of Cypridina hilgendorfii. In connection with his study 

 it may be of some interest to publish the results of my obser- 

 vation on the morphology of the gland carried out sixteen years 

 ago. 



In Cypridina hilgendorfii (Miiller '90, p. 228) the maxillary 

 gland (Oberlippendriise) attains a considerable development, 

 consisting of a number of large gland cells. These cells open to 

 the exterior on five protuberances, one unpaired anterior and 

 two pairs of posterior ones (figs. 1 and 2). The anterior process 

 has five or six pairs of openings. The middle pair is shorter 

 t-han the anterior one and each has only three or four openings. 

 The hindmost pair is the longest of all, projecting over the an- 

 terior wall of the mouth cavity, and each has seven or eight 

 openings along its side. The last pair of protuberances alone 

 is provided with fine hairs. 



The maxillary gland is a group of unicellular glands, as have 

 often been described by previous writers. The longest cells 

 measure nearly 0.7 nmi. in length and reach as far up as the 



435 



