IV WARBLK FLY. 



outside of the hide. These channels (of course examined microscopi- 

 cally) had no lining membrane as is the case further on ; they were 



merely a passage (see fig. 2) apparently 

 gnawed or torn by the mouth-forks of the 

 young maggot, and they varied in direc- 

 tion, being sometimes slanting, or taking 

 a straight course, or so completely curved 

 at the upper part, that it was quite im- 

 possible that this channel could have 

 . > Gc ion, niagm e . \)QQYi caused by the perforation of the 

 ovipositor (the egg-laying apparatus of the female fly), and in one 

 instance in which the maggot-tunnel had only gone about half the 

 way through the hide I found a small soft body lying at the bottom, 

 which, though crushed in taking the section, appeared without doubt 

 to be the maggot. 



The egg is of the shape figured at p. 1, and is thus described by 

 Prof. Riley, late Entomologist of the U. S. A. Department of Agricul- 

 ture, from his own personal observations of warbled cattle in Illinois 

 from 1860-1863, when interested directly in stock-raising, and having 

 the charge of some three hundred head of cattle* : — " . . . The eggs 

 of this Ox Bot are elliptic ovoid, slightly compressed, and have at the 

 hase a five-ribbed cap on a stoiit stalk with which to strongly attach 

 them to the skin of the animal." Prof. Eiley remarks that the grooved 

 and slightly pedicelled enlargement of the end which is attached is 

 admirably adapted for being strongly fastened to the skin, and to the 

 base of the hairs, and all observations that have been recorded point 

 to the fact that the young larva works its way directly from the egg 

 under the skin. "... The structure of the ovipositor clearly excludes 

 the possibility of puncture, for though horny, it has a blunt trifid tip, 

 and is beset at the end with certain minute hairs." 



The point of where the egg is deposited is very important relatively 

 to effect of dressings, and there has been a great deal of what cannot 

 but be considered vague speculation on the subject, as few of 

 authority, excepting Prof. Riley, speak from observation. But we 

 know that the ovipositor is not suited for purposes of boring ; also 

 I can speak personally to the borings through the hide not being 

 such as could be formed by the passage of an ovipositor, and in 

 the absence of any evidence from observation of the eggs being 

 passed down through the hide, I believe that all the different points 

 which W3 know from observation prove that the deposit takes place on 

 the outside. 



* See ' Insect Life.' Periodical Bulletin of U. S. A. Department of Agriculture, 

 Vol. ii., No. 6, pp. 173', 174; Washington, U. S. A., 1889. 



