THE ENTOMOLOGIST. 137 
that of the white dead-nettle being yellow; of the red dead- 
nettle, red; and of the ground ivy, white. Similar observations, 
as to the constancy of insects in confining their visits to the 
same species during the same journey, have been made by 
that accurate observer, Mr. Traherne Moggridge, in respect 
of a species of fumitory in the South of France.—Alfred W. 
Bennett ; 6, Park Village East, Regent’s Park. 
[At page 60 of the first volume of the ‘Entomological 
Magazine’ is a review of Professor Rennie’s “ Alphabet of 
Insects,” from which it seems evident the writer did not think 
professors infallible. 1 believe the fault then, as now, is to be 
found in the fact that professors and teachers of all kinds 
trust too much to books, and too little to observation. On the 
other hand, I think there may be an error in relying too 
exclusively on observation. Book-knowledge often serves to 
test and to rectify observations too hastily made, and is 
therefore of infinite value.—Hdward Newman.) 
A Parasite.—The different species of pheasants have some 
most remarkable parasites infesting them, and indeed there 
are few, if any, members of the vast creation which are free 
from the attacks of parasites in some form or another. I 
recollect finding one of extraordinary size upon a kestrel, and 
I may enumerate others, as the tiny brown creatures taken 
from a hen harrier, or the white elongated forms of those 
found on a sheldrake; however, I have no wish to generalize 
in such a way, unless I knew what the various parasites 
were, but I may mention one whose occurrence interested 
me more than usual. In the autumn of 1873 I had a long- 
eared owl sent me, and whilst inspecting it I fancied I saw 
some insect make a hurried appearance upon the breast of 
the bird, and as quickly shuffle out of sight amongst the 
feathers. I searched most carefully, but without success, and 
I had caught only a glimpse of the creature, which from its 
movements I thought was not an Acarus, even had its size not 
forbidden the belief, so I determined to secure it if possible, 
and the following day, after another close scrutiny, I found it 
under one of the bird’s wings. It proved to be a Dipterous 
fly, with body of a greenish hue, and is, [ suspect, one of the 
Hippobosca genus, for in its side-long movements, its tena- 
cious hold, and general outline, it seemed to proclaim itself a 
relation of the “ forest-fly.” I subsequently obtained two 
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