584 ORGANS OF SECRETION. 



glandular follicles, which open into its interior. The long, 

 capacious chylific stomach is also well provided with similar 

 small, short, isolated follicles, the proper gastric glands, 

 which open around its whole inner surface. 



The liver of insects consists always of long biliary tubuli, 

 varying much in their number, sometimes simple, sometimes 

 with small follicles developing along their sides, sometimes 

 isolated and free at their extremities, often anastomosing 

 and continuous at their distal ends, and opening into one or 

 more points near the pyloric extremity of the stomach. 

 There are often two, or four, or six tubuli on each side of 

 the stomach, and when thus few, they are very long and 

 convoluted, and frequently united in pairs by the anasto- 

 mosis of their distal ends, so that each tubulus returns to 

 terminate in the part whence it originated. Sometimes there 

 are several dozens of these tubuli, and when thus numerous, 

 they are generally quite free, shorter, and separate at their 

 closed ends, and open around more than one point of the 

 stomach. These tubuli sometimes form a small sac, or 

 gall-bladder, to collect their secretion before transmitting it 

 to the stomach. By opening the stomach of the bombyx, 

 and compressing the biliary tubuli, Malpighi in 1687, observed 

 the yellowish coloured bile flow by a distinct aperture into 

 the cavity of the stomach. The liver is least developed in 

 carnivorous insects, as seen in cicindela (Fig. 118. C. m. m.) 

 and in cimex (Fig. 118. D. m. m.), and most developed in 

 the phytophagous species, as seen in melolontha (Fig. 118. 

 A./c.l.m.); and the gall-bladder is sometimes double, as 

 already seen in pyrrhocoris (Fig. 118. F./). 



The pancreas is less developed and less constant in insects 

 than the liver, and commonly presents itself in the form of 

 one or more simple follicles, opening into the pyloric portion 

 of the chylific stomach, near to the entrance of the hepatic 

 tubuli, as in pyrrhocoris (Fig. 118. F. q.), where, at least, six 

 small pancreatic follicles are seen entering the stomach, close 

 to the opening of the long hepatic tubuli. Numerous other 

 relations of the chylopoietic glands of insects belong to the 

 general account of their digestive organs already given. 



The urinary organs, like most other glands of insects, 

 consist of one or more elongated isolated follicles, or simple 

 tubuli uriniferi, which open into the lower or cloacal portion 



