138 LETTERS TO MR. GIBB [CHAP. xv. 



my sketch, you would see what you thought. The workings 

 do not seem to me as regular, but yet there is a strong 

 resemblance. 



I am working up the Gadflies as well as time allows, and 

 through courtesy of Mr. Janson have had a loan of a 

 volume published in 1842 of a serial called "Isis" so as 

 to be able to study the very special paper in it by Zeller, 

 which is the authority on some of the important points, and 

 which cannot now be bought by itself. I thought this was 

 a kind help, for the whole book is very costly. 



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 Tabanidce as he has, 

 which will be a great help. I have had an artist down from 

 London who has made most beautiful drawings for en- 

 graving of the fly's foot (pis. xxm. 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 observa- 

 tion and figure. 



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 fnligi- 

 nosa, of which it is stated in Frederick Smith's British 

 Museum Catalogue of British Fossoria] Hymenoptera [bur- 

 rowing four-winged insects], p. n, 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 



