XXIV INTHODFCTION. 



rectum, and by the absence of a caecum and of valves *. A small 

 csecum is said to exist in Bhinopoma, but I have not succeeded in 

 finding one in any of the individuals of the single species of that 

 genus examined by me ; in Megaderma spasma, at a distance of 

 about three quarters of an inch from the anus, there is a small csecum- 

 like appendage about one tenth of an inch in length, but I have not 

 been able to discover any opening in the intestine communicating 

 M'ith it. 



In all species of Chiroptera the liver is remarkably large ; the left 

 lateral lobe is always well developed, and in Microchiroptera occa- 

 sionally equals half the size of the whole organ. Except in the Desmo- 

 dontes, the right and left lateral fissures are very distinct, and often 

 extend almost to its attached border. The liver of the Megachiroptera 

 is easily distinguished from that of the Microchiroptera by the ill- 

 defined condition or absence of the Spigelian lobe, and, in some 

 genera, by the remarkably large size of the caudate lobe, for in the 

 Microchiroptera the Spigelian lobe is very large and lies in the tri- 

 angular space between the oesophagus and the pyloric end of the 

 stomach, while the caudate lobe is small, in most species forming a 

 ridge only. 



In Pterop-ns the left and right central lobes are nearly equal and 

 are divided by a notch behind ; the gall-bladder is contained in a 

 notch in the concave upper surface of the right central lobe ; the 

 right and left lateral fissures extend almost to the attached margin 

 of the organ ; the left lateral lobe is as large as the conjoined 

 central lobes, and greatly exceeds in superficial extent the right 

 lateral, which is irregularly quadrilateral and thick, and its concave 

 outer side is moulded on the right kidney ; the caudate lobe is very 

 large and tongue-shaped, and extends backwards as far as the poste- 

 rior margin of the right lateral lobe, having its outer concave side 

 applied to the inner convex surface of the kidney ; the Spigelian lobe 

 is very small and ill-defined. Cynopterus comes nearest to Ptero- 

 2>us in the form of the liver; but the caudate lobe is even larger, 

 extending considerably behind the right lateral lobe, and having 

 part of its free extremity moulded round the posterior surface of the 

 kidney. In Cephalotes the caudate lobe is equally large, but the 

 gall-bladder lies in a concavity between the right central and the 



* This accounts for the rapidity with which, in the frugivorous species at 

 least, the food eaten passes through the body, and explains how the astonishing 

 voracity of these animals is indulged in without inconvenience. (See a note on 

 the voracity of C'ynopfenis rtiargmatus, p. 83.) 



