116 CONTAGIOUS DISEASES OF DOMESTICATED ANIMALS. 



particularly those iu relation with the dnodeuuiu, we have found in the 

 case of young pheasants attacked with the gapes very active larva.', 

 almost twice as large as those just emerging from the egg, seeking 

 their way. 



4. In the cellular peritracheal tissue, iu the neighborhood of the crop 

 of one of the young pheasants referred to above, we found, stretched 

 out parallel to the trachea, a young female syngame, already colored 

 red, o"""' (.2 inch) long, with the mouth formed like that of the adult. 

 and even sexually matured. We think that it was a syngame which, 

 having been delayed in the migration, failed to reach the mucosa of the 

 trachea in due time and now could no longer do so, because the adult 

 structure of the mouth parts presented an impediment to its march 

 across the tissues. 



5. In the inclosures of M. de Janze, at Gournay (Eure), which were 

 desolated last year by the gapes, and which have presented this year 

 some cases of this disease, the following fact has often been observed 

 and verified by ^r. de Janze himself: The young pheasants affec.-ted 

 with this malady frequently expel, in a fit of coughing, plump, fat syn- 

 games full of eggs. The other fowls near by consume with avidity the 

 worms thus ejected, which they, no doubt, regard a.s earth-worms, or 

 the red larvae of the large tipulte which resemble them, and of which 

 they ^re very fond. Two or three weeks later these young pheasants 

 are sure to present symptoms of the malady — the slight, aborted hiss- 

 ing cough, which is so characteristic, and the gaping, which has gained 

 for this disease its English name. 



6. For the purpose of verifying experimentally the ficcuracy of the 

 facts related above, the authenticity of which, however, did not give 

 rise to any doubt, we fed to a female parrot, on the 7th of August, four 



pairs of large syngames. We had just received from Mme. de la E 



de Montmirail some young pheasants, dead from the gapes, from which 

 we obtained an ample number of syngames ; the parrot being the only 

 subject we had for exi>eriment at the time. On August 28 this bird 

 began to cough and to gape. On September 10 it died, suffocated by 

 numerous syngames which we found, at the autopsy, crowded in the 

 trachea. 



Considering the large number of eggs — several thousand — which a 

 cadaver of the female syngame contains, and the relatively small num- 

 ber of parasites — about thirty or more pairs — which reach their destina- 

 tion, or, in other words, come to maturity, we may form an estimate of 

 the prodigious number of larva^ which die on their way or never suc- 

 ceed in finding it. It is, moreover, a law of nature, especially true of 

 parasites, that the number of eggs laid is larger in projiortion as the 

 chances of destruction during the earlier period of existence are more 

 numerous. 



The great variation in the size, and hence in the age and the degree 

 of development, noted among the syngames attached to the trachea of 



