NOTES ON DISTOMA ENDEMICUM. 



57 



considerable calibre. This portion is always filled with spermatozoa 

 and might be termed the seminal reservoir. After an irregular winding 

 course, it reaches the ventral suclvcr, assumes a position to the right of 

 the median line and finally joins the front end of the uterus a short 

 distance within the sexual opening. 



It remains yet to say a few words about the eggs. They are 

 unusually small, measuring 0.028 — 0.03 mm. in length and 0.016 — 

 0.017 in breadth. In those eggs contained in the hind end of tlie uterus 

 the shell is colorless and transparent. Each encloses an egg-cell and 

 a number of yolk-cells, the nuclei of which can easily be demonstrated 

 by coloring. In the anterior portion of the uterus, where the egg-shells 

 have assumed a dark-brown or dark-olive color, embryos are already 

 formed. Such an egg is represented in fig. 3, magnified 640 times. 

 In the interior 3 distinct bodies beside some yolk-granules are seen. 

 One of these bodies is a granular mass of triangular or irregular shape. 

 Behind this body, away from the operculum, there is a second mass 

 of larger size and clearer appearance. The third body lies mainly 

 on the side of the second and has the form of a rod, slightly curved and 

 often showing constrictions. This elongated body does not form a 

 part of the embryo ; it is probably the remnant of yolk-matter. 



Embryos can be forced out of shells by a sharp tap on the cover- 

 glass. In fig. 4 I have draw^n an embryo as examined in weak acetic 

 acid. It has an elongated oval shape, measuring 0.025 m.m. in length. 

 The body slightly tapers toward the hind end. I believe I have seen 

 an indication of head-papilla. The delicate skin is covered all over by 

 cilia, which are turned posteriorly. The anterior portion of the body 

 is made up of a few large cells with granular contents. The hind 

 portion contains small cjHs of clear appearance, probably germinal cells. 

 These two groups of cells apparently correspond with the two granular 

 bodies that we have seen within the egg-shell. There are no eye-spots. 



