22 



THE FEMALE. 



The female has been found united with the male on the 

 esophagus when .055 inch long and .0025 inch in width, and in its 

 adult state sometimes measures .875 inch in length, by nearly 

 .045 in width. It is of a bright red color from the absorption of 

 the hematin of the blood upon which it lives. When mature it is 

 irregularly cylindrical, curved, and often variegated by the white 

 winding uterine horns filled with eggs. The tail is conical and 

 just in front of its extremity is the anus. The vulva is a short 

 distance back of the head and is attached at its anterior part to 

 the caudal extremity of the male. At its posterior part this union 

 is incomplete, the perfect eggs passing out here through the 

 vagina. The digestive and genital organs can be traced within. 



PREVENTION OF THE GAPES. 



The very best results which can be attained from the study of 

 disease is its prevention. If the only way in nature by which fowls 

 contract the gapes is from eating earthworms containing the 

 embryos of Syngamus, it follows if none of these were eaten the 

 disease would become extinct. We believe, after many years' 

 study of the gapes, that this is the only natural way in which 

 fowls contract the disease, but, should they take in the embryos 

 in any other way the disease would be equally liable to occur. We 

 have never observed this to take place, and believe it never docs 

 except through the instrumentality of man. Adopting this view, 

 there are two methods of prevention, either one of which will 

 prove effectual. First, keep young fowls from the ground where 

 earthworms are infested by the embryos. Second, destroy the earth- 

 worms containing them, when the fowls could be allowed their 

 liberty. We had thought a third method rmght be added, namely, 

 to mix with the bird's food some anthelmintic, which, if worms 

 containing the embryos were eaten, would destroy them without 

 injuring the fowl. This opinion was changed after the experi- 

 ments detailed belowwere concluded. The first method consists in 

 either keeping them on wooden floors, or some grassy plot or 

 ground where the disease has never existed. The second method, 

 that of destroying the earthworm, involves the question as to 

 what is the best method of doing this. The article to be chosen 

 must be cheap, effective, readily applied, and safe to use. We 

 have experimented with three different substances, each of which 



