﻿THE CATTLE GEUB« OE OX WAEBLES 21 



larvse by the saddle. The writers hare no authentic records of the 

 complete development of larvse within a horse, but this probably 

 occurs occasionally. 



Brauer (8) has described a Hypoderma larva from the horse and 

 was uncertain of its identity. Ormerod {71) gives considerable in- 

 formation on the occurrence of Hypoderma larvse in horses in Eng- 

 land, but none were positively identified. It is very probable that 

 H. iovis or H. Imeatum was concerned in these cases. 



The writers have made but a single test of the development of 

 Hypoderma larvae in a horse. On March 15, 1922, and the following 

 day two flies (H. lineatum) caught in nature were permitted to 

 oviposit on the hairs, on the feet, and at the base of the tail of a 

 horse. Five daj^s later most of the eggs had hatched and the larvse 

 had penetrated the skin as indicated by a copious exudation of 

 serum, some of which was slightly tinged with blood. There was 

 also some swelling in the region where the larvse penetrated at the 

 base of the tail. However, the animal did not show any indication 

 of irritation at the time the penetration took place. In about a 

 week the heavy scab formed by the dry serum loosened. Frequent 

 examination of the host during the next year failed to reveal the 

 presence of a single larva. 



Since it appears that Hypoderma larvse may occasionally develop 

 in the goat {Oaqjra sp.), several tests were made of this possibility 

 with Angora goats. In 1921, 25 eggs were placed by a fly upon a 

 goat's heels. Three days later some of these were observed to be 

 hatched and the larvae penetrating, but the animal showed no special 

 uneasiness. During the following spring about 86 eggs of H. 

 lineatum were placed on the legs of another goat. Some of these 

 were ready to hatch when the hairs bearing them were cemented 

 on the animal. Other eggs of this lot were shown to be viable 

 by incubator tests, but no lesions could be found on the host. Unfor- 

 tunately one of these goats was lost the following summer, but the 

 other failed to develop any larvse. On April 10, 1923, a fly was 

 induced to deposit 61 eggs on the legs of a kid. Although the eggs 

 from this fly were fertile, the host showed no uneasiness and exhibited 

 no lesions of penetration. Apparently the eggs were lost before 

 hatching. No special difficulty was experienced in getting the flies 

 to lay eggs on this host. 



On December 22, 1920, 30 larvae, 10 to 15 millimeters in length, 

 taken from the gullets of cattle, were inserted under the skin between 

 the knee and the hip of an Angora goat. A few days later a careful 

 examination of the skin showed the presence of small objects a few 

 inches from the point of insertion, which were tliought to be some 

 of the larvte. On January 17. 1021, two of the larvte reached the 

 hack in the lumbar region and perforated the skin. These soon 

 scabhed over, however, and on March 4 the lumps were considerably 

 reduced in size, and the larvae were found to be dead. 



Two Angora goats were infected on November 29, 1922, by means 

 of an incision on the lower par-t of the thigh. One of these received 

 18 and the other 20 larvae of //. lineatum,, averaging 13.2 millimeters 

 in length, from the gullets of rattle. On the for-mer of these two 

 goats 3 larvie aj^peaicd under the skin of the back in the luinl)ar 

 region, 2 on December 12, and 1 on December 19; and on the latter 



