Nov.. 1896. THE STUDY OF THE ORANG-OUTANG. 317 



untouched. It is quite different as regards the surface anatomy of 

 the brain. The fissures, lobes, sulci, and convolutions of brains 

 of individual orangs have been described and figured by Bischoff 

 (222), Chapman (229), Fick (235, 127), Rolleston (266), Sandifort 

 (271), Schroeder and Vrolik (275, 196), Tiedemann (281), and Barkow 

 (go). The surface anatomy of the brain has been treated in a more 

 general way, and from a greater number of specimens, by Cunning- 

 ham (115, 116), Benham (94), Bischoff (221), Gratiolet (130a), Huxley 

 (49&), Kiikenthal and Ziehen (151), Pansch (176), and Eberstaller 

 (298^). The Island of Reil and the third frontal convolution have 

 been specially studied by Cunningham (115, 116, 117), Herve (48), 

 Marchand (157), and Riidinger (188^). As to the relative develop- 

 ment of the lobes to each other, the relationship of the cerebellum to 

 the cerebrum, and of both to the cranial walls, one may consult 

 Cunningham (118), Fere (234), Flower (237), Schroeder and Vrolik 

 (196, 275), Hamy (136), and Rolleston (266). Beevor and Horsley 

 (220) have investigated the motor areas of the cortex, and Hitzig 

 (246^) has made some observations respecting the morphology of these 

 areas. The weights of the several parts of the brain have been 

 estimated by Moeller (166), and Keith (146) has dealt with the brain 

 weight as a whole. 



The Muscular System. — There is not to be found anywhere in 

 literature one complete account of the muscular system of the orang. 

 The fullest descriptions are those given by Beddard (92), Chapman 

 (229), Church (231), Fick (235, 127), Huxley (49^), Owen (263, 261), 

 Vrolik (210), and Sandifort (271). A great deal can be ascertained 

 from drawings given by Cuvier (231a) and Barkow (90), and some- 

 thing from the writings of Camper (228), Mayer (160), and Westling 

 (287). The muscles of the extremities have received most attention, 

 having been fully described by Hepburn (45), Langer (252), and 

 Barnard (219). Quite a number of anatomists have paid attention to 

 certain muscles or groups of muscles : Lartschneider {152a) to the 

 muscles of the pelvis; Ruge (70), Bischoff (7), and Rex (67^) to the 

 muscles of the face; Bischoff (100) to the extensor indicis and flexor 

 pollicis muscles; St. John Brooks (106,107) to the short flexor 

 muscles of the thumb and Httle finger ; Keith (148) to the rectus 

 abdominis thoracicis and flexor profundus digitorum ; Ruge 

 {190, 268, 269) to the rectus abdominis, muscles of the planta and 

 extensors of the toes ; Koerner (251) and Mayer (161) to the muscles 

 of the larynx ; Ottley (260a) to the muscles of the eye; Westling (287) 

 to the muscles of the tongue and pharynx; Seydel (198, 199) to the 

 serrati muscles of the back. Langer (252) and Fick (235) record the 

 weights of most of the limb muscles, a labour which seems well worth 

 the extra trouble, as weight is far the best index of degree of function. 

 By adding together these various accounts, one may obtain a fairly 

 complete picture of the muscular system of an orang. The in- 

 voluntary muscles still require investigation. 



