56 



at 9 A. M., eight days and sixteen hours after the feeding, I killed 

 the chick and found one single and twenty-nine pairs of syn- 

 gami. 



Exp. 14. On August l-lth, at 7 p. m., fed a young robin, just 

 from the nest, a large number of embryo syngami hatched in 

 water, as in the preceding experiment. It was kept in a cage 

 hanging under a tree, and fed by the old bird. 



August 22d, morning : Robin had some symptoms of the 

 gapes, such as rapid breathing, an occasional gape and shake of 

 the head, and was inclined to sit on its perch, instead of stand- 

 ing up, as usual. August 23d: breathed more rapidly, and evi- 

 dently quite ill. August 26th: Robin continued to grow weaker 

 and breathed more rapidly, and at times gaped, but the gaping 

 was not as prominent a symptom as in the case of chicks. The 

 robin died the morning of the 29th, the fifteenth day from the 

 feeding. On examination, three fair sized syngami were found 

 in the trachea, not enough to fill it up, so as to produce much 

 gaping. The rapid breathing, which was the most prominent 

 symptom, was readily accounted for by extensive deposits in 

 both lungs, more especially the right. The lower part of each 

 lung was affected, and the diseased condition, doubtless, resulted 

 from the irritation of the parasites.* 



Exp. 13 proves that the embryo of Syngamus does not neces- 

 sarily have to pass through an intermediate host; that the earth- 

 worm is simply a bearer, in which it lives in its embryonic con- 

 dition, and through which it obtains access to fowls. This chick 

 was kept in the barn, and all other sources of the disease exclud- 

 ed, which was not the case with the robin. The time from the 

 feeding to the production of the disease in the chick was the 

 same as when earthworms were fed, which is good evidence that 

 it is the embryo instead of the tg^ in those, which causes the 



*This condition resulting from parasites is mentioned by Dr. N. H.. 

 Paaren, in the American Entomologist, Vol. II, page 149; also, by Dr. George 

 M. Sternberg, from M. Lanlaine, in an article on the " Production of Tubercu- 

 losis by Inoculation," in the American Journal of Medical Sciences, Vol. 

 LXXXIX, page 18. 



