THE BRAIN IN THE EDENTATA. SS^ 



dactyla ; but in view of its cerebral features vre are justified in looking for its ancestry in 

 tlie early Eocene Ungulate stem, long after tlie Carnivore stock from whicli the American 

 Edentata are probably derived bad branched off from the Crcodonta, which the American 

 palaeontologists regard as the common progenitors of all these diversely specialized 

 animals. Such a view does not necessarily conflict with the opinion of Kitchen Parker, 

 who, in knowledge of many resemblances between the skulls of Orycteropus and Wiyncho- 

 cyon, suggested that the former may be an off'shoot from the Insectivorous stock *. From 

 the generalized structure of Orycteropus and the simplicity of its brain, we may infer 

 that it has not advanced far beyond the stage of the jirimitive Creodonta, which are 

 nearly related to the Insectivora primitiva, while all its near relatives have either been 

 vastly changed in body, limb, and brain to meet the fierce competition by specialization 

 of form and improvement of cerebral structure or have succumbed in the struggle and 

 become extinct. 



The evidence for this distant kinship wdth the primitive Ungulates is not absolutely 

 conclusive, but it clearly demonstrates the distinctness of the Aard-vark from the 

 Ant-eater, and suggests the relationship indicated in the foregoing paragraphs. In a 

 memoir to which I have already referred, Oldfield Thomas remarks that " we are wholly 

 in the dark as to what other mammals " Oryctero2ms " may be allied to " (p. 248). Under 

 such circumstances it is important to place on record even such indecisive straws of 

 evidence as I have herein supplied, as denoting which way the tide of evolution 

 may have flowed in bringing down to the present generation this pecuHar waif of a 

 past age. 



The brain of Uanis is in many ways peciiliar. Max Weber gives three records of 

 the brain-weight wdiich are singularly discordant : — 



Manis javanica, $ , body-weight 1750 gr.^ braiu-weigbt 9'5 gr. 

 „ ?, „ 3500 gr., „ 11 gr. 



8000 gr., „ ISgr.t 



Unless these weights refer to animals of different ages we are at a loss to explain 

 the extreme variations of the body-weight. Dubois says % that the immense superiority 

 in the brain-weight of Myrmecoplmga over that of ILanis is " a new reason for 

 separating the American Edentates from those of the Old World." It seems to me 

 that this is quite a fallacious argument. Among the American Edentates themselves, 

 we find in the three families extreme variations in brain-weight, and in a natural group 

 like the Hodentia we find contrasts § quite as marked as that which exists between the 

 Great Ant-eater and the Pangolin \. If we are going to separate these two animals 

 we must find some more genuine distinction than that which Dubois suggests. 



* W. K. Parker, " On the Structure and Development of the Skull in the ITammalia. — Part. II. Edentata." 

 Proc. Royal Soc. London, vol. xxxvii. p. 80. 



t This weight we owe to Kohlbrligge, Natuurkdg. Tijdschr. Ned.-Indie, Iv. 



i Eugene Dubois, " Poids de I'Encephale chez les Mammiferes," Bulletins de la Societc d'Anthropologie de Paris, 

 t. viii. iv'' serie (1897) p. 374. 



§ Dubois himself has noticed this fact in tl.e Rodents, op. cit. p. 373. 



II Vide Max Weber's tables, op. cit., Gegenbaur's Festschrift. 

 SECOND SERIES. — ZOOLOGY, VOL. VII. 53 



