526 JOSEPH STAFFORD, 



especially distinct, closely placed epithelium cells whose inner faces 

 carry strong cilia, acting inwards towards the ovary. Also for a 

 short distance up the Laurer's canal are cilia whose motion apparently 

 is not always in the same direction. Cilia can also be found but 

 indistinct in sections. The portion beyond the entrance of the vitelline 

 duct has the same structure, with the exception of the cilia, but when 

 we reach the ootype we find much thicker walls, lined with high 

 epithelial cells, each of which encloses a nucleus containing chromatin 

 granules. The beginning and end of the ootype are easily deter- 

 mined after once one has closely observed the structural conditions. 

 But at first it is not easily recognized to be a distinct organ, as it 

 is here very difficult to procure sharp outlines, on account of the 

 density with which the cells are crowded together, their contents, as 

 well as the opacity of the surrounding shell gland. The latter is 

 of a conical form with broad end beginning near the yolk duct and 

 small end extending out along the ootype. Round the entrance to 

 the ootype the unicellular elements of the shell gland assume a radi- 

 ating arrangement at the centre of which are frequently found strongly 

 réfringent drops of secretion. Sections fortunately falling lengthwise 

 through these two organs (Fig. 12) have shown me that the numerous 

 ducts of the unicellular glands continue to pass through the walls of 

 the ootype for approximately the half of its length. 



The difficulty of procuring clear outlines, as well as the fact that 

 the shell gland flattens out to a large surface which escapes the 

 attention when one is following minute details, and also because it 

 shades into parenchyma so as not to give a plain demarcation no 

 doubt account for these organs being previously overlooked. The 

 presence of a body in sections , lying to the left of the ovary , of a 

 denser structure and smaller cells than the surrounding parenchyma 

 first attracted my notice and afterwards from a careful following out 

 of the oviduct the structure of the ootype again enlisted my attention. 

 Afterwards, I found that both belonged together, as two organs but 

 having a united purpose. The cells of the shell gland measure about 

 12 to 18 //, nucleus 5 //, nucleolus 1,5 /^ (in sections). The proto- 

 plasm flakey or uniformly stained with sometimes one or two more 

 deeply colored bodies. 



The receptaculum seminis uterinum, following the ootype, 

 does not reach the dignity of a specialized portion of the oviduct. 

 Early in sexual maturity it is filled with sperm , before there are 

 eggs in the oviduct. When the latter is full of eggs in all stages 



