599.8 372 



IV. 



An Introduction to the Study of Anthropoid 

 Apes.— IV. The Gibbon. 



THE greater part of the literature on the gibbon is devoted to a 

 consideration of its specific and generic characters. Our know- 

 ledge of its anatomy is based upon a very small amount of material. 

 Until five years ago, when Kohlbriigge published dissections of four 

 specimens, our information was confined to incomplete descriptions 

 of the anatomy of five animals. The paucity of research upon this 

 animal, which, for many reasons, is the most interesting of the 

 anthropoids, is not due to lack of material, for within a recent period 

 there have been thirty-five specimens, belonging to various species, 

 in the Zoological Gardens at London. After their arrival in Europe, 

 they are soon at the disposal of the dissector, for unfortunately they 

 do not live long in confinement, few of them more than a year. Of 

 three gibbons that were in the Rotterdam gardens, two lived for about 

 a month, the other died after a sojourn of eight days. 



The Nervous System. — The brain of the gibbon is comparatively 

 small and simple, resembling in its form and topography much more 

 the brains of cynomorphous monkeys than those of the three great 

 anthropoids. Recently it has received a great deal of attention. 

 Kohlbriigge had at his disposal the brains of twelve specimens (eight 

 of Hylobates syndadylus, two of H. leuciscus, one of H. lar, and one of 

 H. agilis), but his observations refer mostly to weight and measure- 

 ment, and only slightly to the convolutions and fissures. Waldeyer 

 (326, 327) has given a very full account of the fissures and sulci of 

 three brains {H. syndadylus, H. leuciscus, and H. lar), with accompany- 

 ing figures. The figures which BischofF (293) gives of the brain of 

 H. leuciscus are extremely good. Deniker (17) has given a clear account, 

 accompanied with figures, of the brain of a foetus of about full time. 

 Figures of the brain of H. syndadylus are given by Sandifort (271). 

 Kiikenthal and Ziehen describe the fissures of the brains of H. Jwolock, 

 H. lar, and H. leucogenys, Ziehen of H. muelleri, and other references to 

 the surface anatomy of the brain will be found in papers by Broca (103), 

 Herve (48), and Eberstaller (298^). Flower (301) and Cunningham 

 (118) have examined the relationship of the cerebrum to the cere- 

 bellum, and of these to the skull-wall. The brain-weight and ratio 

 has been estimated by Keith (146). The nerves have received a con- 



