REMARKS ON 
THE FIGURES 
OF PLATE I. 
THE VERTEBRAL TRANSVERSE PROCESSES COMPARED WITH ONE ANOTHER THROUGH SERIES. 
W E proceed to identify the homologous elements of the several classes of vertebra whose serial order 
constitutes the human spinal axis, to know clearly what are the elemental parts which shall be 
properly characterised by one and the same name, and which can have no other name than this applied to 
them, without confusing the ideas. 
The name once fixed upon the form, shall attend upon that form and 
no other ; and even though we shall discover it to increase or decrease beyond its most ordinary dimensions, 
from time to time, or in several places, still it shall not escape our identification of it as being one and 
the same thing. 
The figures marked A are such as form the human 
cervical spinal region, and these are forms absolutely 
homologous both as to their general character and their 
several elementary pieces. The central form, marked A”, 
represents those elementary pieces separated the one from 
the other. These are the primary formative pieces of the 
cervical vertebra, and consist of the centrum or median 
element named the body, and the two lateral pieces 
arching dorsal from it to form the neural arch. Where 
these two lateral pieces meet behind, they are surmounted 
by another element named the spinous process. The so- 
called transverse process of the cervical vertebra is com- 
pound. It consists of double elements; the one placed 
posteriorly is marked 2 in fig. A”, and is a structural 
part produced from the lateral piece of the neural arch ; 
one elementary nucleus of osseous deposit fashions all parts 
of this lateral piece. 
The anterior piece 8, of the cervical compound transverse 
process, is totally distinct in early life from the posterior 
piece,2. In adult age, for the most part both these pieces 
become united, but still they hold in the very same position 
in which they were first laid distinct. It is impossible 
(even when we see them in their state of coalescence) to 
forget that they were once distinct elements. We call 
the fused condition of both these elementary pieces the 
cervical transverse process, but we know it to be composed 
of double elements, the posterior element being an apo- 
physis of the neural arch, whereas the anterior element is 
one developed per se. In figure A”, therefore, we say 0 is 
not to be confounded with 2, and also that even when we 
call their fused condition by the common name of transverse 
process, this name neither changes the elements as to their 
proper position or character. Even when we see them as 
in figs. A’ and A” combined, we still know that they were 
once separate, and that although now presenting themselves 
fused together, they have not changed sides. The anterior 
element is still itself, and no other. The posterior element 
is still itself, and no other. Whether these elements hold 
separable or become fused together, we fully understand 
that the anterior part of the transverse process of the 
figures A’ A” A” is not the posterior part. Even though 
we mark them with distinct letters, such as la of fig. A’, 
or 26 of fig. A”, or 3c of fig. A’, still we know the positive 
identity of the forms themselves, that the posterior element 
is always posterior, and that the anterior element is always 
anterior. 
The figs. marked B’ B” B” are human dorsal vertebre, 
In what respect do these dorsal 
In no 
and are homologous. 
vertebree differ from those of the cervical class? 
other particular than that these dorsal forms are minus an 
element, and that the cervical forms are plus that same 
element. Fig. B” shows the primary elemental pieces 
separated. The process called transverse, and marked 2 in 
fig. B”, is absolutely homologous with the process marked 2 
in fig. A”. Both these processes are identical as to position 
and mode of development. They are the apophyses of the 
neural arches, and are produced of the same nucleus which 
fashioned the neural arch. The process marked 2, fig. B”, 
cannot be said to be the homologue of the element marked 
6 in fig. A”, because these elements do not correspond in 
any respect whatever. The piece 6 of fig. A” is produced 
distinctly, and created anteriorly to the piece 2 of the same 
figure. The piece marked 2 fig. A” is the apophysis of the 
neural arch, and so likewise is the piece marked 2, fig. B”, 
therefore it is that we call them homologous. In the fig. 
A” we find an element marked 4, but we have no homo- 
logue for 6 in fig. B”, therefore it is that we say fig. B” is 
minus the piece 6. Hence we conclude that the cervical 
vertebra A”, minus the element 4, equals the dorsal verte- 
bra B”, or otherwise that B”’, plus the element 0, equals 
the figure A”. We say, therefore, that fig. B” is only 
different from fig. A” by being minus the piece 6. 
The figures marked C’C”C” are human lumbar vertebree, 
and are homologous. In fig. C” we.see the elements 
separated, and these are marked with letters corresponding 
to those of fig. A”. The parts 2 and 6 of fig. CO”, are 
identical with the parts 2 and 0 of fig. A”. These parts of 
both figures correspond both as to position and mode of 
development, therefore C’” is homologous with A”, but C” 
is different to B” for the same reason that A” was different 
to B’, that is, B” wants the element 6, which we find in 
figs. A” and C”. 
The figures marked D’D’ D’” are human sacral vertebree 
and are homologous. So also are they homologous with 
