ASCARIS MYSTAX. 327 



have already touclied upon certain facts in connection with the 

 embryos and their probable mode of introduction into the human 

 body, it win here be desirable to notice very briefly the leading 

 phenomena associated with the development of the eggs. 



If a full-grown female Ascaris mystax be carefully slit open, and 

 the exposed reproductive organs be then removed and spread out, 

 the latter will be found to consist, first, of a utero-vaginal canal 

 1§" in length ; secondly, of two uterine horns, each ^ an inch in 

 length ; and thirdly, of two remarkably long and dehcate ovarian 

 tubes, which terminate in very fine coecal extremities. "Within 



Fia. 70. Dissection of the female reproductive organs ot Ascaris mystax; a, the fine coecal ends 



of the ovarian tubes ; b, vitelligene folds ; c, oviduct ; d, horns of the double uterus ; e, f, 

 utero-vaginal passage. — Original. 



these blind ends, the egg-germs first make their appearance in the 

 form of minute free nuclei, and nucleated cellules, which on their 

 passage downwards become surrounded by granules to form the 

 future yelk. The first part of the tube may therefore be looked 

 upon as the strictly ovarian portion (germstock), whilst the suc- 

 ceeding division may be regarded as the vitelligene organ (yelk- 

 stock) ; these are followed by the oviducts, which open into the 



