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NATURAL SCIENCE. October, 



figures of one or more skeletons are given by Bolau (lo), Dwight (123), 

 Barkow (90), Lenz (53), Meyer (58), Tyson (208), Vrolik (210), and 

 Traill (206). Cunningham (118, 119), deals with the curve and 

 cartilage of the lumbar region of the vertebral column; Broca (104), 

 Chudzinski (112), and Paterson (179) with the sacral and coccygeal 

 vertebras; Keith (149) with the manubrhim stemi; Rosenberg (187a) 

 and Wyman (215) with the regional series of vertebrae; Sutton (201), 

 Rosenberg (187^), Lucae (54), and Vrolik (210) with the bones of the 

 hand ; Lazarus (153), Lucae (54), Humphry (142), and Thomson (204) 

 with the bones of the foot. Records of measurements of bones are 

 given more especially by Rollet (i86n), Meyer (58), Issel (144), Lucae 

 (54), Slack (73), and Wyman (87^). 



The Teeth. — Great weight has been placed upon the form and 

 structure of the teeth of the chimpanzee for classificatory purposes, 

 especially for estabHshing its generic value, and upon the cusps of 

 the last molar teeth for establishing the specific value of certain 

 groups of chimpanzees. It must be admitted that the enamel on the 

 cusps of the gorilla's teeth assumes, as a rule, a sharp crystalhne form 

 never found on the teeth of the chimpanzee, and gives support to 

 those that separate the gorillas from the chimpanzees as two well- 

 marked and separated genera ; but the last molar teeth, being of the 

 nature of degenerating structures in the chimpanzee, and therefore 

 very variable, are quite unreliable characters for splitting the group 

 into species or sub-species. Very • probably a fifth cusp appears 

 much more frequently on the last lower molar of the individuals of one 

 variety of chimpanzee than on the last lower molar of another variety ; 

 but its presence or absence can never be accepted as diagnostic. It 

 will be some time before such points can be settled, because the 

 skulls only have the teeth in a fit condition for study from a little 

 time before until a little time after the animals have reached maturity, 

 and it must take time to accumulate such a series. Irregularities in 

 the dental series have been recorded by Bateson (92) and Bischoff 

 (96). Descriptions and figures are given by Duvernoy (22), Ehlers 

 (23), Beddard (93), GiglioH (31), Gratiolet (131) and Barkow (90). 

 Practically nothing is known of the dates of irruption, although some 

 data in connection with this matter may be picked from Beddard 

 (93), Broderip (105), and Magitot (56). Topinard (82) treats of the 

 variations of the cusps. Huxley, Tomes, and Owen (174) deal with 

 the teeth in their well-known general treatises. 



The Alimentary System. — Figures or descriptions of the tongue, 

 dealing mostly with its papillae, are given by Bischoff (7), Cunningham 

 (118), Duvernoy (22), Dwight (123), Ehlers (23), Flower (28), 

 Gratiolet (131), Humphry (142), Cavanna (109), Mayer (162), 

 Symington (202), Traill (206), and Tyson (208). It is very noticeable 

 in the literature of the anthropoids, as exemplified by the literature 

 on the tongue, how subsequent observers pay particular attention 

 to, and discuss, the points raised by their predecessors, so that one 



