July 31, 1895.
I have a promise from Professor Mik, who is a special authority on flies, that when he returns to Vienna he will let me have such duplicates of the Tabanidæ as he has, which will be a great help. I have had an artist down from London who has made most beautiful drawings for engraving of the fly’s foot (plates [XXIII]. [XXIV].), but I greatly want some dissections made of it, and I have only this morning heard where I could get this minute work done. Would you mind the trouble of once again letting me have two or three Forest flies? I should be very much obliged, for though I keep the specimens most carefully that you let me have, some quite fresh would answer much better for dissection.
It is very curious that until Mr. Goodall (a highly accomplished veterinary surgeon) noticed the long bristle attached to the H. equina foot, no one except that wonderful observer De Geer appears to have noticed it, or what is perhaps still more astonishing, repeated De Geer’s observation and figure.
PLATE XXIII.
Horace Knight ad nat del West. Newman lith. Foot of Forest Fly (Hippobosca equina, Linn.) Side view greatly magnified
PLATE XXIV.
Horace Knight ad nat. del. West, Newman lith. Foot of Forest Fly (Hippobosca equina, Linn.) Seen from above greatly magnified.
August 13, 1895.
I am much obliged by your letter of the 8th inst. with observations of the effect of temperature and weather on presence of Forest fly, and now again this morning, and very much, for the supply of Forest flies, which were alive I should say by the grumbling in the corn-stem, until I chloroformed them.
Your “black ants” appear to me to be Formica fuliginosa, of which it is stated in Frederick Smith’s British Museum Catalogue of British Fossorial Hymenoptera [burrowing four-winged insects], p. 11, that “this species is at once recognised by its jet-black colour; its usual habitat is the vicinity of a decaying tree or old post.” I only twice met with this kind in my father’s woods, each time, curiously enough, one of my brothers who had a great fondness for ornithology saw the Hoopoe. As this rare bird is stated to have a fondness for this special kind of ant I conjectured its presence was caused by the fuliginosa being present. Their workings were wonderfully destructive in the felled stump which they chose for headquarters. I certainly think you need no advice from me on the head of dealing with them, but it just occurred to me that, if they come in a definite line still, and you could not run them up to their starting point, it might answer to put a couple of half-decayed stumps across their line of march. Might they not adopt the suggested new settlement?