21 



the gapes. Both male and female embryos do not develop beyond 

 a certain point until union takes place. After this they pass up 

 into the trachea, where they attach themselves to the mucous 

 membrane and attain maturity. 



ANATOMICAL DESCRIPTION. 



We shall not attempt any extended anatomical description of 

 Syugamits trachcalis. The illustrations accompanying this investi- 

 gation will show its appearance in the different stages of its ex- 

 istence. We will briefly say that the mouth in this Genus is large, 

 circular, and surrounded by four outer membranous and six inner 

 chitinous lips. The young worm has eight inner lips, two of 

 which uniting with two others, reduces the number to six in the 

 adult worm. Within it is hollowed out, and contains around the 

 opening to the digestive apparatus, eight lance-like organs, which 

 are supposed to pierce the mucous membrane for extracting the 

 blood of its host. 



THE MALE. 



The male has been found coupled on the external wall of the 

 esophagus of the chick when .035 inch long, and .002 inch wide. 

 At maturity it attains the length of about .24 inch, and a breadth 

 of about .02 inch. The diameter of the head exceeds that of the 

 body, which is round, and its posterior part, containing the genital 

 organs and anus, is united to the anterior part of the vulva of the 

 female by a membranous hood-like organ, called the caudal 

 pouch. This organ is elongated in front, with about one-third 

 of its diameter cut out on its posterior part, where it is free from 

 the female. It is supported by eight principal ribs, which are sub- 

 divided as follows: The posterior ribs on either side are double; 

 next to these on each side they are trifid, followed by a single rib, 

 between which are the two anterior ribs, also trifid. These divi- 

 sions of the ribs, eighteen in number, each have at their extremity, 

 which reaches to the circumference of the caudal pouch, a disk 

 or sucker, by means of which the male attaches itself to the genital 

 organs of the female and maintains so strong a hold, that even 

 after death they are separated with much difficulty. There is no 

 actual growing together of the organs, as has been the commonly 

 received opinion, for they can be separated entire by careful 

 manipulation in diluted glycerine. Within is seen the digestive 

 and internal genital organs. 



