476 The House Fly. [ August, 
myself too near them, the flying egret would give a loud, shrill call, 
and they would all rise up immediately and be gone for perhaps 
an hour. I frequently disturbed them, and so uniform was their 
action at such a time that I could exactly describe in advance to 
a friend what would be their movements when I alarmed them. 
So unvarying was their method of leaving and returning to the 
meadow that it seemed only explicable by considering it the pre- 
determined routine, resulting from a consultation had among them 
when circumstances first led them to the spot in question. 
As an instance, also, of these birds apparently ‘studying the 
situation,” I daily noticed a change in their habits as the waters 
began to subside and restricted their range of submerged land. 
They seemed to know full well that an open meadow, six or 
eight inches under water, afforded no “ cover ” for their arch- 
enemy, man, but that he might crawl dangerously near in the 
long, tangled grass, now again exposed. The indication of this 
supposed train of thought on the part of the herons consisted 
in their increased suspicion, and the steadily increasing number 
of circular flights on the part of some of their number to see if 
any danger was near by. 
It were useless to endeavor to give a detailed account of their 
many interesting movements, all of which were so indicative of 
genuine thought ; but the whole series of observations, as I now 
recall them, and the perusal of my field-notes, more than ever 
fully convince me that these egrets, like all birds, depend upon, 
and are successful in life, I may say, more from their reasoning 
powers and their quality than they trust to or are dependent upon 
the operations of instinct. d 
THE HOUSE FLY. 
BY A. S. PACKARD, JR. 
A BRIEF history of the common house fly, which abounds to 
such an annoying extent in August, may not be out 0 none” 
especially as until within two or three years we were quite ın Ke 4 
dark as to its mode of life and transformations. The Mémoires 
of the Swedish count, DeGeer, published just one hundred year 
ago, contain the first notice of the house fly, while a fuller ae 
count is given in an obscure book by Bouché, a German st ee 
ogist; published in 1834. Two years ago the writer m 
special study of the mode of growth and life-history of the BY: 
the leading points of which are here reproduced. 
1 On the Transformations of the Common House Fly. (Proceedings of the Bosto 
Society of Natural History, xvi., 1874.) 8vo, pp. 14. 
‘ 
