HEREDITY. 469 



this type can with equal propriety be called, as I have 

 shown, the primitive placental molar. The lemur is 

 the highest form next to man which displays it, but it 

 was universal among the placentals at one geological 

 epoch. It is possible that Topinard's suggestion as 

 to the cause of its appearance in man is the correct 

 one, as I made the same many years before, but that 

 does not affect its value as an evidence of reversion, 

 as in the cases already cited. There are various other 

 ways in which molar teeth may degenerate, besides 

 reversion to trituberculy, with which dentists are fa- 

 miliar, and which may be explained as Topinard and 

 I have done ; i. e., by change of food; but why the 

 regular and normal mode should be trituberculy, and 

 not one of those other modes, requires additional ex- 

 planation. This explanation is that a regular or nor- 

 mal retrogressive modification of a structure is likely 

 to be a return on the line by which it advanced. This 

 is atavism or reversion. 



That the anthropoids have been directly derived 

 by descent from the false lemurs rather than from the 

 Old World monkeys (Cercopithecidae) is probable for 

 various reasons which I have pointed out on page 157. 

 I mention now that this view is somewhat confirmed 

 by the recent discovery by Forsyth-Major, in Mada- 

 gascar, in beds of Plistocene age, of a skull of a new 

 genus of Lemuridae with tritubercular molars, whose 

 single species is nearly as large as a chimpanzee. 



In closing these remarks, I call attention to the 

 frequent muscular and occasional cerebral anomalies 

 found in the negro, which are of simian character, and 

 which indicate simian descent. An excellent synopsis 

 of these has been given by Dr. Frank Baker in his 

 address at Cleveland in 1888 as Vice-President of the 



