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general appearance as seen in the engravings. We believe it is 

 taken in by the earthworm with its food, and passes down into 

 the intestine, where it remains until transferred within its host to 

 the digestive organs of some bird, or after a time passes through 

 into the soil and perishes. This method of taking in the embryo 

 by the earthworm is the common law in nature, through which all 

 creatures, man included, obtain their intestinal parasites. 



THE EMBRYO OF SYNGAMUS IN THE FOWL. 



The embryo passes into the crop within the intestine of the 

 earthworm. We wish to determine at what point it leaves the 

 digestive canal and passes into the lungs and trachea of the chick. 

 We have never been able to trace the embryo below the esopha- 

 gus, after many examinations of chicks dead of the gapes. If we 

 admit that they do not pass through the proventriculus and giz- 

 zard alive, which I have no doubt is the truth, there are only two 

 organs, the crop and esophagus, through which they could gain 

 admission to the lungs. The crop is simply a dilatation of the 

 esophageal structures, and acts as a reservoir for the food. We 

 believe the embryo passes through the esophagus just above the 

 proventriculus, for the following reasons: The distance to the 

 lung structures is very short, only the thin wall of the esophagus 

 intervening. The orifices of the lenticular glands of the esopha- 

 gus are of greater diameter than the embryo, so it could readily 

 enter through them. That it does so we believe, for we have 

 found them beneath its mucous membrane. The pulmonary 

 bronchi ramify over the outer surface of the esophagus, through 

 the substance of which there are numerous tubular structures, 

 which, it is not improbable, may be connected with them. We 

 have seen the embryo just emerged from the esophagus into the 

 lung, and have in all the chicks carefully examined for that pur- 

 pose, after dying of the gapes, found several echymosed spots, 

 which looked as though the embryos had passed through. We 

 have also found them recently united on the outer wall of the 

 esophagus, one pair being the smallest we ever saw. In dissecting 

 chickens dying of the gapes, we have, many times, Found the 

 esophagus adhering to the lungs, as we believe from the inflam- 

 mation caused by the passage of the embryos. This condition of 

 echymosis, and adhesion of the esophagus to the lungs, we have 

 never found in any chicks we have dissected which did not have 



