160 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
representative of similarly long and scattered hairs which occur 
in the chimpanzee, macacus, and baboons. 
Lastly, it may be here more conveniently observed than in the 
next chapter on Embryology, that at about the sixth month the human 
foetus is often thickly coated with somewhat long dark hair over the 
entire body, except the soles of the feet and palms of the hands, which 
are likewise bare in all quadrumanous animals. This covering, which 
is called the lanugo, and sometimes extends even to the whole fore- 
head, ears, and face, is shed before birth. So that it appears to be 
useless for any purpose other than that of emphatically declaring man 
a child of the monkey. 
9. Teeth.—Darwin writes: 
“It appears as if the posterior molar or wisdom teeth were tending 
to become rudimentary in the more civilized races of man. These 
teeth are rather smaller than the other molars, as is likewise the case 
with the corresponding teeth in the chimpanzee and orang; and they 
have only two separate fangs. .... They are also much more liable 
to vary, both in structure and in the period of their development, 
than the other teeth. In the Melanian races, on the other hand, the 
wisdom-teeth are usually furnished with three separate fangs, and are 
usually sound (i.e., not specially liable to decay); they also differ from 
the other molars in size, less than in the Caucasian races.” 
Now, in addition to these there are other respects in which the 
dwindling condition of wisdom-teeth is manifested—particularly with 
regard to the pattern of their crowns. Indeed, in this respect it would 
seem that even in the anthropoid apes there is the beginning of a 
tendency to degeneration of the molar teeth from behind forwards. 
For if we compare the three molars in the lower jaw of the gorilla, 
orang, and chimpanzee, we find that the gorilla has five well-marked 
cusps on all three of them; but that in the orang the cusps are not so 
pronounced, while in the chimpanzee there are only four of them on 
the third molar. Now in man it is only the first of these three teeth 
which normally presents five cusps, both the others presenting only 
four. So that, comparing all these genera together, it appears that 
the number of cusps is being reduced from behind forwards; the 
chimpanzee having lost one of them from the third molar, while man 
has not only lost this, but also one from the second molar,—and it 
may be added, likewise partially (or even totally) from the first molar, 
as a frequent variation among civilized races. But, on the other hand, 
variations are often met with in the opposite direction, where the 
