COLEOPTERA. 443 



from its cell, and appears floating as a pure oil on the water. In lean 

 beetles the air-cells are very distinct ; yet something may be observed 

 mixed with them, which is the empty cells of the adipose membrane. 

 This may serve as epiploon. 



The female parts of generation consist of two ovaria, two oviducts, 

 and a common duct, which answer to the vagina, two horns of the 

 uterus, and ovaria of quadrupeds. These are situated in the anterior 

 part of the belly, just before the intestines. The opening of the common 

 duct is pretty large, and just before the anus ; however, they are di- 

 stinct openings. Pretty near the union of the common oviduct with the 

 rectum is a small bag, which in appearance communicates with the 

 oviduct. On each side of its external opening, just in the angle 

 between it and the border of the body, are parts apparently connected 

 with the parts of generation, therefore most probably glandular. 



In the ovaria are formed the eggs, several at one time ; thence they 

 come into the first oviduct on each side, at one time, so that they are 

 always in pairs. The eggs are oblong, rounded off at the ends, which 

 are nearly of an equal size ; they are yellow, but when put into spirits, 

 black. This may be owing to coagulation, as the redness in the lobster 

 is owing to that. 



I found eggs in the oviducts [of Geotrupes ?] in October, when they 

 had returned to their winter quarters, and been dug up. 



The male parts of generation 1 consist of five or six testicles on each 

 side ; they are round white bodies lying on the sides of the abdomen, 

 connected to the intestines, &c. by means of the air-vessels and the 

 yellow substance above described. Prom each passes a duct, all of 

 which unite into one, which is coiled up into a sort of epididymis. 

 This common duct passes towards the tail, where it joins its fellow from 

 the other side, forming there a knob or bulge. Besides the testicles 

 there is a canal arising from no particular body, but by a blind point, 

 which hangs loose, and is coiled up in the lateral part of the abdomen, 

 reaching higher than the testicle ; its general course is towards the 

 tail ; and it joins the duct from the testicle. This canal can hardly be 

 reckoned part of the testicle, but may answer the purpose of a pi'ostate 

 gland or vesicula seminalis. The common [sperm-]duct is much stronger 

 in its coats than those leading to it, and is pretty straight : it enters 



1 [Hunter left many preparations of the male organs of Coleoptera. In pre- 

 paring the Catalogue of his Physiological Series, I was able to determine the fol- 

 lowing genera and species : — Melolontha solstitialis, No. 2352 ; Mclolontha vulgaris, 

 No. 2353 ; Blaps mortisaga, No. 2354 ; Geotrupes stercorarius, No. 2355 ; Scara- 

 besus, No. 2356 ; Cetonia auratd, Nos. 2357, 2358, 2359 ; Megasoma Titanus, No. 

 2360 ; Lampyris splcndidula, No. 2362 ; Cerambyx moschatus, No. 2363.] 



