INTRODUCTION. 



In the following pages we present the results of experiments 

 made for the purpose of determining the intermediate host of 

 the gape worm of fowls. We have endeavored at the same time 

 to trace out the life history of this parasite, in its various stages 

 from the egg to the perfect worm, also to devise means for the 

 prevention of the disease caused by it among fowls. 



The object of undertaking the work was two-fold. First, it 

 was thought if its intermediate host could be discovered the 

 disease might be prevented to a great degree, and much good 

 result therefrom. Second, the love of original investigation and 

 a determination to work out the life history of this parasite, 

 which, although well known in its mature condition in the 

 trachea of fowls for about one hundred years, had thus far, in its 

 embryonic state in nature, remained unknown. The work has 

 been exceedingly difficult, for several reasons. When the inves- 

 tigation was begun, I knew nothing about Entozoa. Microscop- 

 ical work was also comparatively new. Living in a small vil- 

 lage, I had no public libraries to consult, and was dependent for 

 the literature of the Entozoa on a few books which I procured 

 during the investigation. My profession also left me little leisure, 

 and the most of this work has been done at such odd times as I 

 could spare from other duties. I wish here to express my thanks 

 to that eminent naturalist, the late Dr. Joseph Leidy, of Phila- 

 delphia, for many favors in inspecting my microscopic slides, and 

 for advice and encouragement in the work. Valuable, indeed, 

 were the services he rendered me. I am under obligations to 

 Lord Walsingham, of England, for books to aid in the investi- 

 gation. Friends in the Buffalo Microscopical Club, and neigh- 

 bors have also assisted me in various ways. I have freely con- 

 sulted Dr. T. Spencer Cobbold's work on "Parasites," also Pro- 

 fessor L. G. Neumann's treatise on "Parasites and Parasitic Dis- 

 eases of Domesticated Animals," and Dr. Pierre Megnin, "On 

 the Gapes Disease in Gallinaceous Birds." Finally, I trust these 

 pages will not be scanned with too critical an eye, for, doubtless, 

 imperfections will be found. I can only say that I have honestly 

 endeavored, according to the best of my ability, to place before 

 the reader the life history of one of the humblest of creatures, a 

 worm, but which, nevertheless, plays well its own part in this 

 world of animated nature. 



