Ca 
1865.] AXIAL SKELETON IN THE PRIMATES. 597 
In Galago (fig. 8, h), Lagothria (fig. 11, h), and Mycetes (fig. 2, h) 
there are certain extra and backwardly projecting processes, which 
are more conveniently to be described with the lumbar region, where 
they are more developed. 
The transverse processes do not project so much upwards (i. e. 
dorsally) in any other genus as they do in Man. Therefore the 
longitudinal groove existing on each side of the series of spinous 
processes, and bounded externally by the series of ends of the trans- 
verse processes, is deepest in Man. The width of this groove conti- 
nues from before backwards most equal in the Nycticebine, then in 
the Simiine, and then in Man, where it appears narrowed at its 
posterior (lower) part, owing to the great difference existing between 
the length of the transverse processes of the most anterior (upper) 
and that of those of the most posterior (lower) portions of the 
dorsal vertebrae. 
In Hylobates the dorsal vertebral groove is slightly interrupted by 
an accessory process at the thirteenth vertebra. It is so also in 
Nyctipitheeus ; but in Ateles at the twelfth. In the other forms 
this interruption takes place at the eleventh, or even, as generally in 
the lower Stméiade and Hapale, at the tenth vertebra. The distal 
ends of the dorsal transverse processes are often more or less enlarged 
antero-posteriorly, though the extent of this enlargement varies much. 
In the Gorilla it is considerably more marked than in Man ; but 
often very much more so in Hylobates, and above all in Ateles. This 
expansion is due to the nascent metapophyses and anapophyses, which 
will be described later. 
The increase in breadth (transverse diameter) of the bodies of the 
vertebre, as we proceed from before backwards, is exceptionally great 
in Man, Hylobates, and Cynocephalus; it is considerably less in Stmia 
and Troglodytes, and is at its minimum in the Nycticebine, as is 
also the increase in antero-posterior extent. 
The spinal nerves pass out by notches in almost all species. In 
Man, Nycticebus, and Loris these notches are deeper than in the 
other forms; but in Perodicticus (fig. 12) and Arctocebus we meet 
with quite a peculiar condition, namely the direct perforation of the 
neurapophyses in all the dorsal vertebree. This foramen is situated 
behind the capitular and beneath the tubercular process. In 4re- 
Zocebys another, smaller perforation, running from before backwards, 
pierces the root of the transverse process in each dorsal vertebra, 
except the first and the thirteenth. 
Lumpar VERTEBRE. 
The lumbar region varies considerably both as to the number of 
its component vertebree and as to its relative extent compared to that 
of the other regions of the spine. 
The greatest number is presented by Loris and Indris, viz. 9 ; the 
least in Troglodytes, where there are sometimes only three. In Man, 
the Orang, and Gibbons* there are normally 5; in Ateles sometimes 
5, though more generally 4; in Lagothrix 4. In all the other 
* Daubenton records six (see Buffon’s Hist, Nat. t. xiy, p- 104). 
