86 NATURAL HISTORY 



of the body, surrounded by the air-vessels and the silk-vessels. To- 

 wards the anus it becomes smaller, forming what may be called gut, 

 and which is afterwards elongated into a gut, lying coiled up on each 

 side of the stomach ; under the above described air-vessels, there are 

 also four long canals, two on each side : their beginning is forward, near 

 the beginning of the stomach : they pass backward and toward the begin- 

 ning of the intestines, becoming rather larger ; they then unite into one 

 on each side, and at last enter into the gut, or termination of the stomach. 

 This is what I suppose to be the liver ; probably they may secrete a 

 liquor (juice) similar to that of the pancreas 1 . These appear to become 

 longer and smaller in the adult or wasp -state. In the interstices of 

 these* parts is a kind of cellular membrane, having also a vast number 

 of white bodies in it, which appears to be analogous to the fat in the 

 old ; for we find in young animals in general that the substance in the 

 place of the fat in the old is hardly fat : the same in the belly of the 

 chrysalis. They have a number of lateral air-openings, which all unite 

 into one canal that passes from head to tail • from which passes inwards 

 toward the stomach, a vast number of air-cells, as also laterally into 

 the different parts. These are now mere ramifying vessels, probably 

 from air being only wanted for respiration and not for flight ; therefore 

 they are not enlarged into cells. 



Of the Silk Glands. — On each side of the body intermixed with the 

 above substance, are canals for the purpose of secreting the juice for 

 the covering of the cells, somewhat similar to the silk-worm. They 

 begin by two canals on each side near the tail, and pass, very much 

 convoluted, towards the head. These unite into one duct which opens 

 at the mouth, through which the juice passes to form the silk. These 

 canals make up the largest part of the substance between the skin and 

 the stomach, and which makes the animal shrink so much after it has 

 spun the lining of its cell. These substances immediately under the 

 skin are divided into two portions, one on each side ; which division 

 we see through the skin on the back, being divided by the heart : and 

 we also see it divided on the fore-part by a dark line, so that the 

 cellular membrane on each side do not commonly unite with each 

 other. 



I began my account of the wasp in the summer with one female 

 wasp, and have traced her operations till she produced assistants, and 

 I have still continued the work till the whole was completed ; but I 

 have yet only spoke of her breeding at large. It is now necessary 

 I should take notice of her offspring, because there is a peculiarity in 



1 [Urea has been discovered in it.] 



