284 COMPARATIVE ANATOMY OF THE TEETH. 



maxillary bones, and are preceded by deciduous ones. 

 These latter appear between the 5th and 2*7 th month; are 

 about two inches in length, one third of an inch in diame- 

 ter, and are shed between the first and second year. In 

 about a month or two after this period, the permanent 

 tusks are described as cutting the gum, and are then about 

 an inch in length. 



At birth the alveolus of the permanent tusk is a round 

 cell placed at the posterior and inner part of the temporary 

 alveolus. The tusks are called the incisor teeth of the ele- 

 phant, and are considered, in proportion to the body, the 

 largest of all the teeth. They are stated to have measured 

 nine feet in length, having a base of eight inches, and 

 weighing 150 pounds. This is an unusual weight, the 

 more common being from fifty to seventy pounds. 



In some varieties the tusks are straight, and point 

 downwards, and in others of a still more anomalous kind, 

 one tusk has been seen horizontal, and the other vertical. 

 The molar teeth are of immense size and complex structure. 

 The crown is mostly hid in the socket, only a small portion 

 appearing above the gum. It is divided into several per- 

 pendicular transverse plates coated with enamel, and then 

 covered with cement which unites the several divisions 

 of the crown; these divisions come together at the base 

 and form the body of the crown from whence the roots 

 proceed. 



In the development of the grinders, the summits of the 

 anterior plates begin to be formed first, and then the others 

 in succession, the anterior being in use before the posterior 

 are formed. The first molar is stated to have four of 

 these vertical plates or divisions of the crown,, and two 

 roots. The second molar has eight or nine plates, and also 

 two roots. The third molar has from eleven to thirteen 

 plates, and has a small anterior and large posterior root. 

 It is thought these three may probably be deciduous teeth. 



The fourth molar has from fifteen to sixteen plates in the 

 crown and three roots. The fifth molar has from seventeen 

 to twenty plates, appears above the gum about the twentieth 



