1884. Zoölogy. 641 
Dr. Coues’ RENUMERATION OF THE SPINAL Nerves.—The 
suggestion contained in Dr. Coues’ article in the last number 
of the NATURALIST promises to relieve the student of human 
anatomy of certain difficulties. in connection with ‘the spinal 
nerves and plexuses. More important considerations will, 
however, deter comparative anatomists from adopting the sug- 
n 
on. 
The renumeration goes upon the principle that a spinal nerve 
is a strictly “intervertebral” structure, and that it is indifferent 
whether we associate it with the vertebra in front or that behind 
it. Such is, however, not the case. Each spinal nerve belongs 
to a particular vertebral segment of the body, that through whose 
neural arch or behind whose neural arch it issues, and ought to 
be named after that segment. There are many of the lower mam- 
malia, Monotremata, Bruta, Ungulata, in which the spinal nerves 
perlorate the neural arches of the segment to which they belong 
instead of issuing behind them. Thus the first dorsal nerve of a 
horse perforates the neural arch of the first dorsal vertebra. If 
we adopt Dr. Coues’ nomenclature, we should have to say that 
the second dorsal nerve perforates the neural arch of the first 
dorsal vertebra—as unhappy an expression as any caused by 
reckoning eight pairs of cervical nerves. 
n this respect the older nomenclature was less objectionable, 
ere the first spinal nerve was described as “ suboccipital ;” the 
second as first cervical, the eighth as seventh cervical, the ninth 
as first dorsal, &c., to the vertebral segments bearing which 
names the nerves really belong. 
It iS unnecessary to dwell longer on the above line of argument, 
for it has been fully elucidated by Dr. Albrecht (ZoGdlogischer An- 
iger, vol. 111, 450 and 472), who regards the suboccipital nerve 
-i the sole remnant of a proatlantic vertebral segment, traces of 
ali ®Sseous elements of which he finds in front of the atlas in the 
'gator and hedgehog. Whether Albrecht’s proatlas be accepted 
2 anatomists, or whether it be more probable that the segment 
x epa the suboccipital nerve belongs has been swallowed up 
his Occipital region of the skull, does not affect the basis of 
Contention that a spinal nerve belongs to that vertebral seg- 
Of raha, de or behind whose neural arch it issues. 
' tary occipital nerves (with corresponding osseous ele- 
(Mon between the vagus a the first atest nerve in Amia 
coe Jahrb, ix, 190). Sagemehl concludes that all be 
homolo ; describes as the first spinal nerve of Amia is really 
singula the with the nerve of the same name in Teleostei, it 1s 
the latt that no traces of the occipital nerves have been found in 
peared jo iss, indeed, we are to assume that they have 
Toronto in the vagus.—R. Ramsay Wright, University College, 
