MAN AND APES. 
129 
The back-bone of man exhibits a beautiful sigmoid curva- 
ture, and is strongly convex in front in the lumbar region, 
Now it is not in the latisternal apes, but in some of the Baboons, 
that we meet with the nearest resemblance to man in this 
particular. 
The lumbar region of the back-bone exhibits in most apes 
certain bony prominences,* which are rudimentary in man. 
The three highest genera resemble man in this respect, but the 
same resemblance is found in the Slender Lemur (Loi^is) and in 
closely allied forms. 
The sacrum | of man is also nearly as much resembled (size 
not being considered) by that of Loris as by those of the highest 
apes. Again, in the angle which this bone forms with the 
lumbar part of the back-bone, man is most resembled, not by 
the highest apes, but by some Baboons. The same may be said 
respecting the concavity of the anterior surface of the sacrum ; 
and of the three highest genera it is not the Grorilla and Chim- 
panzee which resemble man most nearly, but the Orang. 
The hinder aspect of the back-bone exhibits a number of 
prominences termed spinous processes. These, in most apes, 
are differently directed towards the two ends of the series, so that 
they tend to converge towards a single point in the back. 
They do not do so in man and the latisternal apes, but neither 
do they in Loris and its allies (Nycticehinoe). In that the breast- 
bone, or sternum, is relatively short, and composed but of two 
bones, man agrees not so much with Troglodytes and Simia as 
with the Gribbons, and in the Siamang the sternum is even 
shorter and broader relatively than in man. 
The Orang exhibits a singular peculiarity in that the breast- 
bone long remains made up of ossifications arranged in pairs, 
side by side, successively. (Fig. 17.) 
The normal number of ribs in the Grorilla and Chimpanzee 
is thirteen pairs ; in the Orang and some Gribbons it is twelve, 
as in man. 
In the Orang and Gribbons there are, as in man, five lumbar 
vertebrae ; in the Oorilla and Chimpanzee there are but four, 
and sometimes only three. 
The bones of the neck (cervical vertebrae) in man have but 
short spinous processes, while in the Orang and Grorilla these are 
enormously elongated. It has been proposed to account for 
this latter condition by the great weight of the head and jaws 
in these apes. The little group Nycticebince, however, presents 
* Termed “ Metapophyses ” and “ Anapophyses.” For details as to these 
see “ Pro. Zool. Soc.” 1854, pp. 571-676. 
tlThe “ sacrum ” is the large and solid piece of the hack-hone to which 
the haunch-hones are attached. 
VOL. XII. — NO. XLVII. K 
