442 INSECTA. 



it were interwoven with a convolution of the intestines ; they appear 

 to take their rise from no part, but begin by blind ends. They pass in 

 a very convoluted direction towards the anus, and open into the gut at 

 the above-mentioned stricture. These are exactly the same with those 

 in a silk-moth ; only those of the silk-moth appear to enter higher, 

 just at the termination of the stomach : but it is to be observed that the 

 gut in the silk-moth is much shortened, and the stomach is a bag, so 

 that the entrance of these canals, in the moth, is altered from 

 what it was [in the larval state] when the operation of digestion was 

 going on. 



The liver is composed of two bodies, very large, and placed in the 

 middle portion of the animal close to the back; they are best seen by 

 removing the wiugs, and then the shell which covers the back close to 

 the insertion of the belly into the chest. Under the smooth shell of 

 the back, near the head and higher than the insertion of the wings, 

 would appear to be nothing but the muscles for the motion of them and 

 of the legs. Everywhere within the body of the animal there are 

 oblong bladders having in them air, and a white liquor. These bladders 

 communicate with one another by small ducts [trachea], and by small 

 ducts they are attached to the intestines, muscles, liver, and every part 

 of the body ; and as soon as the ducts attach themselves to these parts 

 they ramify upon them like vessels. In the cavity of the abdomen, on 

 each side, there are two air-vessels running along the lateral parts of 

 the cavity, just upon the inside where the back and belly scales meet, 

 similar to the lateral communications of the air-vessels in the cater- 

 pillar. These vessels have short ones passing from them dfrectly to the 

 skin, where they open externally, I suppose, as in the caterpillar. From 

 them two lateral vessels arrive at a vast number of smaller ones, which 

 pass inwards towards the contents of the abdomen. These vessels in 

 general ramify everywhere on the contained parts, as e. g., the stomach 

 and intestines, the parts of generation, &c. ; and, in their manner of 

 distribution, appear like the ramifications of blood-vessels in other 

 animals. Many of them swell into a kind of aneurisms or bags, which 

 are of various shapes and sizes ; some nearly round, others oblong, &c. 

 Then they become small as before, and ramify as above described. The 

 air-bags are continued from the abdomen into the legs, &c. of the 

 animal : the coats of their vessels are extremely thin and tender, and 

 white, not transparent, but opake, like white paint. They have a 

 great deal of fat, which is very much detached, and floats in the cavity 

 of the belly. It is very white, and so mixed with the air-cells as to 

 obstruct their distinct appearance, in those which are veiy fat. When 

 the contents of the abdomen are examined in water this fat escapes 



