220 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 1s to 
say as far as concerns the molars, for the tusks have their milk 
forerunners. As to the molars it is apparently only /. 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, 1s quoted 
below.’ 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 Rhinoceros. 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 lke an archaic 
character. No Elephant has a gall-bladder. The lungs again are 
simple in form through their sight 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” of the Elephant 
' Forbes, Proc. Zool. Soc. 1879, p. 420. 
* See Krueg, Zeitschr. wiss. Zool. xxxiii. 1881, p. 652, and Beddard, Proc. Zool. 
Soc. 1893, p. 311. 
