FILARIID.E 



^245 



to the subperitoneal and subpleural connective tissues or to the mus- 

 cular septa, scrotum, or other parts of the body. The small filarise 

 occasionally found in the anterior chamber of the eye are considered 

 l)y most authors to belong to this species. 



Efifect. — Unless present in exceptionally large numbers, these worms 

 do not produce serious disturbance. Their presence in the eye may 

 cause inflammation with bulging and opacity of the 

 cornea for the relief of which operative measures must 

 be resorted to. 



Nothing definite is known as to the evolution of 

 this nematode; the fact that the embryos have been 

 olDserved in the blood of the horse, points to the 

 probability that they pass to the body of a blood- 

 sucking insect. 



2. Habronema megastoma (Spiroptera megas- 

 toma). Filariidae (p. 244). — This is a small nematode 

 with whitish colored body attenuated at the extremi- 

 ties. The cephalic portion is separated from the 

 remainder of the body by a constriction, and is pro- 

 vided with four chitinous lips. The mouth is con- 

 tinued by an infundibuliform pharynx. The caudal 

 extremity of the male is rolled and bears two lateral 

 wings, each sustained by four preanal and one pos- 

 tanal papillae. There are two spicules. The tail of 

 the female is straight and obtuse; vulva situated to- 

 ward anterior third of the body. 



Length of female, 10-13 mm. (3/8 of an inch); 

 male, 7-10 mm. (1/4- 3/8 of an inch). 



Eggs, elongate, 33 microns long by 8 microns in 

 breadth. Development and hatching are within the 

 body of the female (ovoviviparous). The liberated 

 embr3'os measure 600-700 microns in length. 



The life history is not known. 



This species infests the submucosa of the stomach 

 of the horse. They are usually in the right sac, and 

 their presence may be recognized l)y oval or rounded 

 prominences varying in size from that of a hazel nut 

 to that of a walnut. The mucous membrane covering the tumors is 

 unaltered with the exception of a number of perforations at the summits 

 which communicate with the contained cavities. Within the.se cavities 

 are lodged the worms which, on pressure upon the tumor, are extruded 

 together with a purulent matter. 



It is probable that the worms reach their subnmcous lodgment as 

 embrA^os b}' way of the gastric ciypts, the irritation of their presence 



Fig. 127. — .Setaria 

 labiato-papillosa.male 

 at loft, female at right. 



