xx INTRODUCTION 



bands. These pouches are largest and most strongly marked at the 

 oesophageal end, and becoming less and less distinct, quite cease 

 several inches before the pylorus is reached, the last part of the 

 organ being a simple, smooth-walled tube. The fundus or cardiac 

 end of the stomach is formed by a single large sac, slightly constricted 

 on its under surface by the prolongation of the inferior longitudinal 

 band, or that corresponding to the great curvature. The oesophagus 

 enters into the upper part of the left, or pyloric end of this sac, or 

 rather at the point of junction between it and the second (also a very 

 large) sacculus. Furthermore the whole of this elongated sacculated 

 organ is, by the brevity, as it were of the long curvature, coiled upon 

 itself in an irregular spiral manner, so that when in situ the pylorus 

 comes to be placed very near the oesophageal entrance." 



The Proboscis Monkey (Nasalis) is unique in one respect, the 

 nose elongate to such a degree as to make it appear a caricature, other- 

 wise the animal resembles in form the Langurs. The Guerezas, (Col- 

 obus), are chiefly noted for the rudimentary condition of the pollux 

 or its absence altogether ; the long hairs falling as a fringe along the 

 side or over the back, and the long tails usually with a conspicuous tuft. 



The species of Rhinopithecus and Simias are noted for the 

 diminutive nose turned up at the tip. The Hylobatuxe or Gibbons 

 possess a skull not produced at the vertex, long arms with the hands 

 reaching to the ground when the animal stands erect, short legs and 

 small ischial callosities. The species of the genus Symphalangus 

 differ from those of Hylobates in having the second and third digits 

 of the foot united by webs as far as the last joint. 



The great Apes form the family Pongiid.e, and have the skull 

 produced at the vertex in Pongo, but not in Gorilla or Pan. Ischial 

 callosities are absent ; arms longer than legs ; hands reaching to the 

 ankles in the Ourang when the animal is erect, only to the knees in the 

 Gorillas and Chimpanzees. Upright bony crests are never seen on the 

 crania of the last named, but the other two have frequently con- 

 spicuously large bony crests in adult males. The Ourang possesses an 

 os centrali but this, as in Man, is absent in the other two genera. 



As in the rest of the ANTHROPOIDEA the skull of the male can 

 always be recognized by the elongate canines. When walking, the 

 Gorillas and Chimpanzees go on the knuckles of the hands and the 

 soles of the feet; but the Ourangs proceed chiefly by swinging from 

 tree to tree by the assistance of their long arms. 



