22O STOMACH AND BRAIN CHAP. 



ally appear, the first three are considered to correspond to pre- 

 molars. But successional teeth are rare in the genus ; that is to 

 say as far as concerns the molars, for the tusks have their milk 

 forerunners. As to the molars it is apparently only E. planifrons 

 which certainly shows a milk dentition. In Mastodon and older 

 types a milk dentition is commoner. 



The viscera of the Elephant have been examined by many 

 zoologists. The latest paper, dealing chiefly with the African 

 species, but containing facts about its Indian congener also, is quoted 

 below. 1 The Elephant is remarkable in possessing, in addition 

 to the three usual pairs of salivary glands present in mammals, a 

 fourth, situated in the molar region, and opening on to the cheek 

 by many pores. This gland is especially well developed in Rodents. 

 There is a gland which may be mentioned in this connexion, though 

 it opens externally between the eye and ear, known as the temporal 

 gland ; its use does not seem clear. The thoracic cavity of the 

 Elephant, as may be inferred from the large number of ribs, is 

 very large as compared with the abdominal. 



The stomach is simple in form, and the epithelium of the 

 oesophagus does not extend into it as is the case with the Horse 

 and Ehinoceros. A gland or a collection of smaller glands occurs 

 in the stomach, and recalls the " cardiac gland " of the Wombat 

 and the Beaver, also that of the Giraffe. The large intestine is 

 long, rather more than half the length of the small intestine. 

 The caecum is well developed in these animals. The liver has a 

 very simple form, being but slightly lobulated. It is actually 

 only bilobed, but it is important to notice that this division does 

 not correspond to the two halves of the liver. As shown by 

 the attachment of the suspensory ligament, one half consists of 

 the left lateral lobe alone, the other half embracing the remaining 

 primary lobes. The simplicity of the liver looks like an archaic 

 character. No Elephant has a gall-bladder. The lungs again are 

 simple in form through their slight lobulation. Each half in 

 fact is without subdivisions, and is of a triangular form. In 

 this the Elephants resemble the Whales, as in the simple liver. 

 In both cases probably the likeness is due to the permanence of 

 primitive features of organisation. The brain 2 of the Elephant 



1 Forbes, Proc. Zool. Soc. 1879, p. 420. 



2 See Krueg, Zeitschr. wiss. Zool. xxxiii. 1881, p. 652, and Beddard, Proc. Zool. 

 Soc. 1893, p. 311. 



