1884.] of the Plexuses in the Human Subject. 381 
they had been before, the renumeration required to shift the sev- 
eral sets into proper position not having been made. Hence 
arose that irregularity which has doubtless tried the wits of many 
a student, puzzled to discover how there can be reckoned eight 
cervical nerves to sevez cervical vertebre, though there is one 
nerve apiece to the dorsal, lumbar and sacral vertebra, and yet 
no break in the whole series ; how it can be that the first cervi- 
cal nerve issues adove the first cervical vertebra, yet the last cer- 
cal nerve issues de/ow the last cervical vertebra; how it can be a 
second cervical nerve which issues between the first and second 
cervical vertebrae, yet a “ first dorsal” which issues between the 
first and second dorsal vertebre; and so forth. There is evi- 
dently something wrong about this; yet it has become so tho- 
roughly ingrained in our nomenclature and descriptions of these 
nerves, that a very poor piece of arithmetic somehow looks like 
a necessary anatomical fact. 
The required correction is self-evident, and wrong numbering 
is very easily rectified. To make the count straight we have only 
to do for the dorsal, lumbar, sacral and coccygeal nerves what 
was done for the cervical when the suboccipital was added to that 
series—drop them all down one vertebra or, what is the same 
thing, raise them all up one number.! Just as what had been in 
the first place first cervical nerve has now become second cervical, 
and what had been seventh cervical nerve became eighth cervical ; 
šo now, what has hitherto been eighth cervical nerve (8th of the 
whole series) becomes first dorsal; what has been twelfth dorsal 
(20th of the whole series) becomes first lumbar; what has been 
fifth lumbar (25th of the whole series) becomes first sacral; what 
has been fifth sacral (30th of the whole series) becomes first 
Soccygeal, and what has been first and last coccygeal (31st 
of the Series) becomes second and last coccygeal (see table 
at end). Of course neither the total of the spinal nerves 
(31), nor the several sums of the sets of dorsals (12), lum- 
bars (5) and sacrals (5) is altered; but there are seven instead 
of eight to be reckoned cervicals, and two coccygeals instead of 
one; and the boundaries of each of the sets shifts up one verte- 
bra. By this simple rectification every spinal nerve is regularly 
Numbered and named by the vertebra above which it issues (since 
1 ear ere 
A nerve Ìs raised numerically when, z. g., a sixth becomes a seventh ; but it is then 
lowered in position 
