274 ANNUAL OF SCIENTIFIC DISCOVERY. 



sometimes to from 14 to 18 F. Wo may say that in insects en- 

 dowed with aerial locomotion the heat is concentrated in the thorax 

 into a focus of intensity proportional to the effective power of 

 flight. These results are in conformity with anatomical data. In 

 the thorax, then, are the strong muscles both of the legs and 

 wings. The latter, being in energetic contraction durinjr flight, 



^J C3 fJ ^j 3 7 



are the seat of an active combustion ; on the contrary, the mus- 

 cles of the abdomen are then inert. We must not be surprised 

 that the equalization of temperature does not take place so rapidly 

 as in the vertebrata. If we consider a wasp (a Polistes or a 

 Sphex), the abdomen of which is united to the thorax only by a 

 slender peduncle, how slowly must the currents of the blood "be 

 transmitted between these two regions through so narrow a strait ! 

 We may see how the heat developed in the thorax during the 

 movement of flight must pass with difficulty into the abdomen, 

 even if it ever reaches this part. 



M. Giraud has ascertained that, in the humble-bees and Xyloco- 

 pa3, the external evolution of heat is in relation to the buzzing. 

 The temperature falls as soon as the insect ceased to buzz, but 

 rises again as soon as the buzzing is resumed ; and this takes 

 place many times successively. 



INSECT DESTRUCTIVE TO THE SILK CULTURE. 



The Secretary of the English Embassy in Japan, Mr. Adams, 

 has lately described an insect called Uji or Oudji, in all its stages 

 from embryo up to full growth, which has become very destructive 

 to the silkworm in Japan. This insect is referred, together with 

 the Chinese fly, to the Diptera. Guerin-menevelle proposes for 

 it the name Tachina Ouclji. Comptes fiendus, t. 70,^. 844. 



THE BORER. 



An interesting report on the ravages of the borer in coffee es- 

 tates has just been published by George Bidie, M.B., F.R.G.S. 

 The coffee-plant, as is well known, is not indigenous to Southern 

 India, but was first introduced into India upwards of two centu- 

 ries ago by a Mussulman pilgrim, Bababooden, who, on his return 

 from Mecca, brought a few berries in his wallet, and taking up 

 his abode in the hills of Mysore, planted them near his tent, and 

 from these the greater portion of the coffee now growing in 

 Southern India has been derived. It is a native of Caffa, in 

 Southern Abyssinia. It is now largely cultivated in Mysore, Cud- 

 door, Coorg, and other parts along the crests and slopes of the 

 Ghauts. It is a remarkably hardy plant, thriving at various eleva- 

 tions, and under the most different conditions of moisture, soil, 

 and temperature. It is, however, liable to the attacks of certain 

 insects, amongst which the borer is the most formidable. This is 

 shown by Dr. Bidie to be the larva of a beetle belonging to the 

 Cerambycidae, and termed the Xylotrechus quadrupes. The female 

 lays its eggs in the bark of the plants, hot sunshine favoring their 



