450 EXPLANATION OF THE PLATES. 



Fig. 26, /. Spermatic organ with the sperm-cells. 

 27. Egg, with perfect embryo. 



28. A piece of the edge of the chitinous skeleton of the female, magnified 250 times. 

 29, 30. Eggs. 

 31. Female of Oxyuris vermicularis, magnified 40 times. 



a, b, c, d, e, as in fig. 26. 



/. Opening of the anus. 



g. Opening of the vagina. 



h, h, h, h, h. The organs preparing and carrying the eggs. They divide into an 



anterior and posterior branch^, of which the first is seen at k. 

 3 la. External termination of the vagina, with the eggs escaping. 



(Figs. 11 15 after Griesinger, the remaining figures, from 1 25, after Bilhaiz). 



PLATE (TAB.) VII. 



1. The male of Trichocephalus dispar, magnified 120 times. 



a. Mouth, with the papillae. 

 a'. (Esophagus. 



b. Convolutions of the intestines, or oesophagus. 



c. The two appendages on the anterior portion of the above. 



d. Narrowing of the intestinal portion behind c. 

 d'. The special stomach. 



d". Intestinal canal lined with epithelium (see fig. 8, d). 



d'". Opening of the intestinal tube and spermatic duct into a common 



cloaca, c. At this point there is a valve for the intestine, and another for 



the spermatic duct. 

 /. Spermatic duct. 



g. Contraction and subsequent terminal expansion of the duct. 

 h. Opening of the spermatic cord into the cloaca. 

 i. A band which covers the penis and its sheath. 

 k. Penis. 



I. End of the penis, 

 rw. Radiating external copulative appendage attached to the end of the penis. 



1. Trichocephalus dispar, of natural size. 



2. Female of Trichocephalus dispar. The lower part of the body from the stomach 



a. The stomach. 



b. The intestine. 



c. The anus. 



d. The vagina. 



e. Convolutions of the uterus. 



The edges of this figure are notched, which is not the case in figure 1, 

 but the notching is always present. 



3. The external copulative appendage of the male (fig. l,w), magnified. 



4. Egg of Trichocephalus dispar, magnified 320 times. 



5. Trichina spiralis in its capsule, after Luschka. 



6. An isolated capsule with a pointed appendage. 



