260 



PARASITES OF MAN 



cephalic segment. In the larval state (= Pent, denticulatum) 

 the body is armed with numerous rows of small, sharply pointed 



spines. The adult female 

 measures from three to 

 four inches in length, but 

 the male is only about 

 an inch long. The genital 

 aperture of the female is 

 situated at the extremity 

 of the tail, that of the 

 male being placed at the 

 front part of the abdomen 

 in the middle line. The 

 mode of reproduction is 

 oviparous, accompanied 

 by a subsequent and com- 

 plete metamorphosis. 



In the mature condi- 

 tion this parasite infests 

 the nostrils, and frontal 

 sinuses of the dog and 

 wolf, and also, though 

 more rarely, the nasal 

 cavities of the horse and 

 sheep. In the pupal and 

 larval states it sometimes 



Fio. W.-Pe*ta,toma txnioide*. (1) Male and (2) female, of OCCUrS in the abdominal 



After n Sa 8 r't ze - TUe *" * eMbiyo ** Uj "**"**' and thoracic cavities of 



the human body, but it is 



more frequently found in herbivorous mammals, such as the 

 sheep, deer, antelope, peccary, porcupine, guinea-pig, hare, and 

 rat. According to Creplin, it infests the domestic cat. In 

 these animals and in man the young worms occupy little cysts 

 within or upon the peripheral parts of the liver and lungs. 

 I have occasionally found them free in the cavities of the 

 abdomen and pleura. 



In the course of the development of this entozoon, Leuckart 

 recognises four well-marked stages. The first is that of the 

 embryo with a boring apparatus. In the second stage, the 

 embryo has become transformed into a motionless pupa. The 

 third is the ordinary larval condition characterised by numerous 

 rows of small spines in addition to two pairs of double claws. 



