162 



PRACTICAL PABASITOLOGY 



for. the most part radially. If the section is taken in front of the 



genital pore, the circumoesophageal nerve-ring will be seen, and will 



appear as if hung upon the four longitudinal lines. 



The mouth papillae should be cut off and prepared for the 



microscope. When seen from above, they are nearly heart-shaped, 



and where the surfaces approach one another 

 they are furnished with a very fine dentition 

 and with sense-organs. These appear as 

 lighter patches, two of which are placed 

 upon the dorsal, and one each upon the 

 ventral, papillae . 



Cross-sections from the male at the level 

 of the sexual glands show, between the 

 intestine and the body-cell, numerous trans- 

 verse and diagonal sections of the coiled, 

 thread-like testes. Similar sections from 

 the female will show the ovary, likewise cut 

 across in various directions ; the two uteri, 

 divided transversely ; and the lumens of the 

 oviducts, which lead from the ovaries to the 

 uteri. Sections of the female organs are 

 subject, however, to considerable variation. 



A section should be taken from the pos- 

 terior end of a male Ascaride, a little in front 

 of the anus. In the centre is the intestine ; 

 above it, the two spiculum sacs are placed 

 symmetrically ; ventrally from the intestine 

 is the duct us ejaculatorius. 



The Ascarides are not, however, the only 

 Nematodes which are deserving of attention. 

 There are numerous varieties belonging to 

 other genera, both parasitic and free-living, 

 which, on account of their transparency and 

 small size, are eminently suited to micro- 

 scopic investigation, and these are readily 

 obtainable. The parasitic forms occur in the 

 intestine of fish, frogs, birds and mammals; 

 while the free - living forms are found in 

 mud, or between decaying leaves in water. 

 Those varieties which live in damp earth 



may be attracted by pouring milk or blood on the ground, or, after 

 removing a patch of turf, by burying a piece of meat just below the 

 surface. The Nematodes will appear in quite a short time, sometimes 

 after a few hours only, and Ehabditis pellio is almost certain to be 



FIG. 83. Oxyuris ver- 

 micularis. Left, female ; 

 right, male, a, Anus, o, 

 Mouth, v, Vulva. Magni- 

 fied. ' (After Glaus.) 



