NATURAL HISTORY OF SELBORNE 147 



like rain, by jumping on the leaves of the turnips or 

 cabbages. 



There is an Oestrus, known in these parts to every 

 ploughboy ; which, because it is omitted by Linnaus, is 

 also passed over by late writers ; and that is the curvicauda 

 of old Mousetj mentioned by Derham in his " Physico- 

 Theology," p. 250 : an insect worthy of remark for deposit- 

 ing its eggs as it flies in so dextrous a manner on the single 

 hairs of the legs and flanks of grass-horses. But then 

 Derham is mistaken when he advances that this Oestrus is 

 the parent of that wonderful star-tailed maggot which he 

 mentions afterwards ; for more modern entomologists have 

 discovered that singular production to be derived from the 

 egg, of the musca chamaleon : see Geoff roy, t. 17 f. 4. 



A full history of noxious insects hurtful in the field, 

 garden, and house, suggesting all the known and likely 

 means of destroying them, would be allowed by the public 

 to be a most useful and important work. What knowledge 

 there is of this sort lies scattered, and wants to be collected; 

 great improvements would soon follow of course. A know- 

 ledge of the properties, oeconomy, propagation, and in short 

 of the life and conversation of these animals, is a neces- 

 sary step to lead us to some method of preventing their 

 depredations. 



As far as I am a judge, nothing would recommend 

 entomology more than some neat plates that should well 

 express the generic distinctions of insects according to 

 LinncEus ; for I am well assured that many people would 

 study insects, could they set out with a more adequate 

 notion of those distinctions than can be conveyed at first 

 by words alone. 



[If you have a desire to see my last birds, please to 

 intimate as much ; but as you intend soon to be in town, 

 might they not as well meet you there, & save a long 

 carriage ? but this shall be as you please. 



I had written thus far when y r letter of the 19 of Mar : 

 arrived. Many thanks are due for y r trouble in ascertaining 

 so many of my Bro rs fishes, and for the honour you have 



