520 
Phenomena of Ontogenesis. 
[October, 
part of the fifth months, however, the middle lobes are 
developed from their posterior aspect, and cover the corpora 
quadrigemina ; and the posterior lobes, of which there was 
no previous rudiment, subsequently begin to sprout from the 
back to the middle lobes, remaining separated from them, 
however, by a distinct furrow, even in the brain of the 
mature foetus, and sometimes in that of older persons. In 
these and other particulars there is a very close correspond- 
ence between the progressive stages of development of the 
human cerebrum and those which we encounter in the 
ascending series of Mammalia. The phases of evolution of 
all parts of the higher organisms are represented by analo- 
gous and permanent conditions among the lower. In the 
organs of smell, for instance, the several steps of develop- 
ment are met with in the various classes of animals : the 
small closed fossae remind us of fishes ; the short nasal 
dudts opening into the anterior part of the mouth, of batra- 
chians. A fine wool-like hair covers the human foetus 
during the sixth month : the whole surface, including even 
the forehead and ears, is thus thickly clothed ; but it is a 
significant fadt that the palms of the hands and the soles of 
the feet are quite naked, like the inferior surfaces of all four 
extremities in most of the lower animals. As this can 
hardly be an accidental coincidence, the woolly covering of 
the foetus probably represents the first permanent coat of 
hair in those mammals which are born hairy. The abnor- 
mal growths of hair occasionally observed in the human 
subject are similar in texture to the lanugo of the foetus, 
and must be attributed to an arrest of development of the 
hair together with its continued growth.* 
It is a noteworthy fadt that, in cases of arrested develop- 
ment, the “ blighted ” part continues to grow independently 
of its stage of development. 
The higher the organism, as a general rule, the more 
perfedt is the state in which it enters the world : even the 
new-born human being is, however, far from fully deve- 
loped ; and Oscar Peschel remarks that the course of 
development of speech in tender years is approximately, if 
not completely, similar to the first attempts to speak made 
by our race. 
A recent discovery of the Rev. W. Ballinger’s has 
enabled us to trace the parallelism of descent and of indi- 
vidual development even further than from the commence- 
ment of embryonic evolution. He has seen a monad with 
* Darwin, The Descent of Man.] 
