13 



into the grouud where they change to the pupal stage (Fig. 2, 2). 

 This stage lasts about a week, in the summer, when the flies emerge, 

 but the last brood of the season passes the winter under ground in 

 this stage. I do not know how many broods occur in this state, but 

 Mr. Howard found that the time from the laying of the eggs to the 

 appearance of the fly was about two weeks, and he therefore esti- 

 niattd that there were seven or eight annual generations in the region 

 of Washington, D. C. The flies of the first brood appear in the 

 spring and succeeding generations occur throughout the summer. 



Figure 2.— l, larva; a, inil btigmita, b, niotoi piocesses 2, pupa; a, anal stigmata' 

 or tubercle — all enlarged. 3, anal luuerule bujI fiiruier enlarged, showing the ridges; c, 

 still further enlai-ged at 5. 4, motor processes of larva still further enlarged. 



(After Smith.) 



HABITS OF THE INSECT. 



This insect confines its attacks to horned cattle, and not only 

 worries them during the day, but, according to the observations of 

 Prof. Smith, keeps it up during the night, whether they are in the 

 barn or in the pasture. During the early part of the season, and 

 when they are numerous, they cluster, when resting, around the 

 base of the horns, often covering them for a distance of two inches 

 or more. The horns are not the only resting places, for toward night 

 they are said to settle in vast numbers upon the back, between the 

 head and fore shoulders, where they cannot be reached by either the 

 head or tail. 



While feeding, the flies work their way down through the hair, so 

 as to reach the skin, but they are exceedingly shy, and fly away at 



