8 



vegetable matters, or they bury themselves in the soil a short 

 distance from the surface." In Lord Walsingham's preface to 

 the essay by Dr. Megnin, he says: "By Dr. Megnin's permis- 

 sion, his memoir is now published in a separate form, the sub- 

 ject of it being one which could not rightly be included amongst 

 the publications' of the Entomological Society, although at the 

 time of offering the prize I was led, by information gathered from 

 various sources, to think it possible that the larvae of some insect 

 acted the part of host to the embryonic form of Syngamus." Dr. 

 Joseph Leidy believed the embryos would be found in some in- 

 termediate host. The above comprised our knowledge on the 

 subject when this research was begun. 



PRESENT INVESTIGATION. 



The present investigation was commenced during the summer 

 of 1883. Great numbers of young poultry dying of the gapes, 

 some of my neighbors applied to me for aid to arrest the disease. 

 Knowing very little about the gapes, but having heard it was 

 caused by worms in the trachea, I made a careful examination 

 of their windpipes, and found numbers of the worms attached 

 thereto by their sucker-like mouths. Never having studied the 

 Entozoa, and having no works on them, I sent a specimen to 

 Dr. Joseph Leidy, of Philadelphia, asking him its name, and 

 where I would find information on the subject. He kindly re- 

 plied, and referred me to Dr. Cobbold on "Parasites," and an 

 article by Dr. N. H. Paaren, in the American Entomologist, Vol. 

 2, page 149. I immediately procured these, and reading the ar- 

 ticles on that subject, could find nothing regarding its origin. 

 I therefore again addressed Dr. Leidy, asking him for the de- 

 sired information. On August 15th, 1883, I received his reply 

 as follows: "The source of the gape worm (Syngamus trachealis), 

 of chickens, has not been discovered. If you have an opportunity 

 of investigating and determining its origin, you may do much 

 service to science. It would be found only in the embryonic 

 or larval condition, in some intermediate host." I thought this 

 was not only a good field for microscopic examination, but also 

 one which, should I succeed in the work, would be productive 

 of much good. Therefore, I commenced an investigation of the 

 coops and their vicinity, where the chicks suffered must from the 

 gapes. About these I found three not improbable sources of the 

 disease: First, the common earth worm (I.iimbriats terrestrls) ; 



