184 CALIFORNIA ACADEMY OF SCIENCES. 



accessory secreting gland, stating that the vasa deferen- 

 tia enter it and continue through it as an integral part, 

 and then pass out as its duct forming the ductus ejacu- 

 latorius. Exception to this view will be taken farther 

 on. According to Kramer the vesicula consists of a 

 rather long duct and of the gland proper, the former 

 widening itself suddenly into the latter. The walls of 

 the duct are composed of several superimposed parts; 

 surrounding all is a loose mass of fibers which are 

 partly nerves and partly connective threads. Within 

 this is a fine structureless coat only here and there pro- 

 vided with distinct nuclei, which is continous over the 

 whole gland. Below this is a thick coat of cells in sev- 

 eral layers. Lining the duct is a two-layered intima; 

 where the duct passes into the gland the two layers 

 diverge, the outer passing over the outside of the gland 

 just beneath the outermost structureless membrane of 

 the duct, which, as stated, passes over the whole gland 

 also, and the inner continuing into the cavities of 

 the gland as their intima. The cells of the cellular 

 layer of the duct are contractile and appear to be 

 muscle-cells corresponding with the muscular cells 

 of the oesophagus and crop. At the lower end of 

 the gland the vasa deferentia penetrate the two outer 

 membranes and run forward beneath a series of wide 

 cell-like plates, with which, however, they do not unite. 

 They proceed forward thus, surrounded by the plates as 

 by a sheath, along the middle of the flat surface of the 

 gland to near its upper end, where they first enter its 

 interior and then within traverse again its whole length. 

 Within the gland they are surrounded by its secreting 

 cells; at its lower end they unite to form the ductus 

 ejaculatorius. It is to be noted that the muscle-cell 

 layer of the duct continues for only a short distance 



