A Nine-Tuskcd Elephant 



269 



the deepest interest. Falconer wrote, in 1856, an essay to prove that the teeth 

 of Deinotherium Elephas and Mastodon formed one series, and in 1862 (in his 

 essay on E. Cohimbi, Nat. Hist. Rev.) he committed himself to the conclu- 

 sion that those three genera sprang from the same common ancestors, and not 

 from one out of the three. Now, had I to construct an ideal ancestor for the 

 three genera, its incisors would assume very much the form of those of the 

 sketch. Elephas would necessitate two large upward curving tusks in the 

 pre-maxillary ; Mastodon, two straight tusks in the lower jaw g and h; and Dei- 

 notherium, two downward curving tusks, also on the lower jaw. I cannot 

 believe that anything happens by accident in nature, and, therefore, I would 

 attribute this abnormal incisive dentition to the law of recun-ence to an 

 ancestral type, just in the same way as Darwin accounts for the recurrence of 

 the colour in domesticated breeds of pigeons. On any other hypothesis it 

 remains a stumbling-block, and a riddle without an answer. All the elephants 



di I II 1. . „ .,_ HT . J di I II 



possess " ^it-~^-^ — 



di o I Oj 



but all the Mastodons 



di I I i> 



all the Deinotheria 



This elephant possessed the incisive characters of the other two 



di ? I 

 di ? I 



genera, plus other smaller teeth, normally undeveloped in the elephant Deino- 

 therium and Mastodon. The teeth seem to be as follows : — 



Upper \ 



Right 



I -H 

 o + 



+ I 

 + I 



Under I 



Left — Incis. 



Ridlt M 



I + 

 I + 



I -t- o = 

 I -h o = 



The smaller upper incisors a and c, which are found in none of the three 

 genera, seem to me to be the result of a struggling after the full complement in 

 the Herbivora. If the first small incisor a be in its true place, then the tusks 

 of Elephas are not incisors one, as they have always been considered to be, 

 but incisors two." 



Fig. 



Fig. 3 shews the disposition of the teeth as thus deciphered. 

 A glance at the lower jaw of the Deinotherium and Mastodon, 



