12 Laj:cllc B. Sturdevant 



seminal receptacle is the last of the genital organs to assume any 

 considerable size, and persists almost to the end of the strobila in 

 each proglottid. This organ was the "yellow spot" of Weinland's 

 description. From the large rounded termination of the seminal 

 receptacle, a small short duct, the seminal duct, proceeds to join 

 the oviduct, which is a slender canal, coming forward from the 

 isthmus of the ovary. After receiving the seminal duct, the ovi- 

 duct changes its direction, running downward and backward to 

 the small shell gland lying in the median line. Here it is joined 

 by the yolk or vitelline duct from the 'gland of the same name and 

 lying also in the median line but close to the posterior border of 

 the .proglottid. From the shell gland the oviduct proceeds an- 

 teriad to the uterus, which lies along the anterior border of the 

 proglottid and dorsally to the ovary. 



The uterus in the earlier stage is merely a transverse strand of 

 cells, which later becomes hollow and grows to the right and left. 

 On reaching the right margin of the proglottid, as it continues 

 to receive eggs, it forms a loop b_v growing around the testes and 

 developing along the posterior border of the proglottid until the 

 left margin is here reached. Further development of these two 

 main tubes is by outpocketings until the entire proglottid is filled 

 by the structure, while the other organs in the meantime gradu- 

 ally become smaller and at last disappear. Cross tubes between 

 these main portions are frequently present. These relations were 

 first worked out by Zschokke. The nuclei of the parenchyma 

 usually persist longest so 'that on the walls of the uterus are fre- 

 quently found minute knobs, where the parenchyma has not yet 

 given way to the development of the uterus and which stain very 

 deeply. My longest specimen shows no peculiar differences in 

 the case of this organ. 



The ovary is bilobed, the two portions being connected by an 

 isthmus which is short and thick or sometimes longer and more 

 slender. ' Each lobe is made up of lobules, which may be short 

 and thick as in my specimen and as Grassi (1888) figured, or 

 long and slender as shown by Zschokke (1888). In one of 

 Grassi's figures the ovary has a distinctly rosette-like appearance. 

 The yolk gland has a general lenticular shape and is made up of 



146 



