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1894.] Entomology. 963 
grub was between the fore legs rather high up, and when expelled, the 
pocket in which it had lived had just the appearance of the interior of 
the anus in mammals. I took the grub home and let it burrow into a 
box of earth from which the fly emerged, something like what I have 
shown in my sketch, on the 22d of May. As a naturalist, I am deeply 
interested in such matters as this, and the fact that I have been able to 
follow my bent in South Africa, South America and many other coun- 
tries does not tend to make me less so." 
The grub, as shown by Mr. Selous in the accompanying drawings, is: 
over an inch and a half long and nearly an inch broad. The pupa 
case is very thick and heavy, with blunt, thick-set tubercles covering 
the outside of it. The fly has the head, legs, ventral region and all of 
the abdomen, except the first segment, black. "The thorax and the first. 
segment are thickly covered with fine silken yellow hair. The wings 
are dark and smoky. 
This species of grub is quite common in the front quarters of rabbits: 
this time of the year, and no doubt if more hunters and naturalists 
knew of its presence in the rabbit and how to save and rear the grub, 
more of the flies might be reared. Mr.Selous has made a start; who 
will follow ?—G. C. Davis. Agr'l College, Mich. 
Insects’ Vision.—Mr. A. Mallack adds another paper to the 
voluminous literature of vision in insects His observations and cal- 
culations, as we learn from the “Journal of the Royal Microscopical 
Society," have led him to conclude that “ Insects do not see well; at 
any rate, as regards their power of defining distant objects, and their 
behaviour, favors this view. They have, however, an advantage over 
simple-eyed animals in the fact that there is hardly any practical limit 
in the nearness of the objects they can examine. With a composite 
eye, the closer the animal the better the sight, for the greater will be 
the number of lenses employed to produce the impression. In the 
simple eye, on the other hand, the focal length of the lens limits the 
distance at which a distinct view can be obtained. Of the various. 
forms of insects examined, the best eye would give a picture about as 
good as if executed in rather coarse wool-work, and viewed at a dis- 
tance of a foot.” 
Chinch Bug Diseases.—Professor F. H. Snow makes an elabor- 
ate report? of his recent extended experiments with the fungus Sporo- 
. Soc. Lond., LV, pp. 85-90. 
* Univ. e Kansas Exp. Station, Third Rept., 1894. 
