iSg6. THE STUDY OF THE CHIMPANZEE. 255 



may safely assume that any point or question, once raised, is sure 

 in time to gather a very full literature round it. It has been so also 

 with the rugag of the hard palate. Bischoff (7), Beddard (93), Ehlers 

 (23), Gratiolet (131), Symington (202), and Waldeyer (211) figure 

 or describe them. Ehlers (23) describes the buccal folds of mucous 

 membrane that occur between the gums and cheeks, and Tyson (208) 

 and Symington (202) also have made observations on the cavity of the 

 mouth. Tyson (208) and Gratiolet (131) have made some obser- 

 vations on the salivary glands. Barkow (90) gives a very fine 

 drawing of the stomach and its blood vessels ; Bischoff (99), Cavanna 

 (109), Gratiolet (131), Traill (206), and Tyson (208) give descriptions 

 of the stomach ; certain points concerning the length and form of the 

 intestine have been recorded by Bischoff (99), Cavanna (109), 

 Chapman (m), D wight (123), Ehlers (23), Flower (28), Gratiolet 

 (131), Huxley (49^), Barkow (90), Symington (202), Traill (206), and 

 Tyson (208), while Embleton (126), Mayer (160), Owen (172, 173), 

 and Vrolik (210) make minor contributions to the same subject. 

 Cunningham (118) gives a very fine figure of a section, showing the 

 topographical relationships of the abdominal viscera. Figures or 

 descriptions of the liver are given by Bischoff (99), Flower (28), 

 Gratiolet (131), Barkow (90), Cavanna (109), Symington (202), Traill 

 (206), and Tyson (208) ; of the pancreas by Bischoff, Flower, 

 Gratiolet, Cavanna, and Tyson {opp. citt.) 



The Respiratory System. — The air sacs of the larynx have got 

 quite an extensive literature of their own, and although their 

 morphology and development may be said to be fairly well known, we 

 are as far from knowing their functional meaning as ever. There 

 have been nearly as many theories regarding their nature as there 

 have been observers. Records of them may be found written by 

 Bischoff (99), Chapman (in), Cunningham (118), Deniker and 

 Boulart (19), Duvernoy (22), Ehlers (23), Mayer (161), Traill (2o6)> 

 Tyson (208), and Vrolik (210). The best work on the structure of the 

 larynx and its muscles has been done by Gratiolet (131) and Mayer 

 (161); but Bischoff (99), Cunningham (118), Ehlers (23), Humphry 

 (142), Barkow (90), Symington (202), Traill (206), Tyson (208), and 

 Vrolik (210) give descriptions of many points worth referring to. The 

 trachea and bronchi have partial records by Aeby (88^), Ehlers (23), 

 and Gratiolet (131). The lungs have been examined by Mayer (161), 

 Ehlers (23), Gratiolet (131), Cavanna (109), Traill, Tyson, and Vrolik 

 {ppp. citt.) The limits of the pleura and its variations have been very 

 accurately described and figured by Ruge (189) and Tanja (203). 

 Cunningham's section (118) shows very well the relationships of the 

 lungs, trachea and larynx. 



The Circulatory System. — The heart of the chimpanzee is so 

 similar to that of man, that there is little left to observe or describe. 

 Its position and relationships have been investigated by Ruge (189), 

 and can be well seen in Cunningham's section (118). Bischoff (99), 



