2 REMARKS ON 
organised bodies. The vegetable as well as the animal 
kingdom manifests the general prevalence of this law, and 
even where we find some few seeming exceptions to it, still 
a closer examination of these will prove that each exception 
may be fairly interpreted as a modification proceeding 
from no other cause than such as admits of being retraced 
to the original condition of symmetry. 
A perfect figure, such as a sphere, is symmetrical by all 
lines of cleavage whatever, provided such lines pass through 
the centre of the sphere. This is also the character of an 
ovoid figure. But such is not the case with the hemisphere. 
Neither do we find it to be the character of any of the 
vertebree as drawn opposite. The hemisphere is not a full 
quantity, and hence it fails of that character which is found 
to attach to the sphere. The vertebra are not cleavable 
by all lines passing through the centre of each, and hence 
perhaps it may be concluded that the vertebre figs. A BC 
D are not full quantities. 
It is evident from the comparison held between the 
sphere and the hemisphere, that the first is symmetrical by 
all lines of sectioning which pass through its centre, mainly 
on account of its bemg plus a hemisphere; and also, that 
the latter is not capable of being thus cleft because of the 
fact that it is minus a hemisphere, that is to say, while we 
regard the sphere as unity or a whole. Now may it not 
also be thought probable that the vertebral quantity fig. B 
or C, which is laterally but not antero-posteriorly sym- 
metrical, possesses this positive and negative character by 
reason of its beimg the minus proportional of some full 
quantity which may be regarded as unity and a whole. 
It will be at once granted that any figure which, like 
fig. B, is bilateral, and hence symmetrical, may be asym- 
metrical as to transverse cleavage solely on account of 
inequality between its anterior and posterior structures. 
If, therefore, lateral symmetry prevails for fig. B, because 
a side repeats a side, whereas antero-posterior symmetry 
is not attending fig. B, because of the back not being a 
repetition of the front, and knowmg as we do that all 
perfect quantities, or whole structures, are capable of beimg 
THE FIGURES OF PLATE XL. 
cleft symmetrically by both modes, we may hence conclude 
that fig. B, not being thus cleavable, is not a full or whole 
quantity; nor is it one, in fact, as we shall hereafter discover. 
So true is it that the whole organic quantity is always 
symmetrically* cleavable by transverse as well as by 
antero-posterior lines passing through the centre, that 
when we find this character to be absent from the form, 
we invariably discover that some quantity has been lost to 
it. This loss of quantity is evidently the means by which 
Nature plans her designs ; but it is long since agreed upon 
by anatomists, that the unity of form can never be under- 
stood by holding a comparison between things considered 
If a figure be but a 
half or a less quantity, proportioned so as to be the better 
as functional designs or fitnesses. 
operative for some function, still this function need not 
prevent us considering the form itself independently of any 
use to which it may be applied. We may acknowledge 
the fitness of a form which is in itself a minus quantity, 
and thereby operative in functional fitness, but still we 
may also know it to be a part of a fuller form whose homo- 
logue is existing somewhere in series, and so (considering 
the form per se and not functionally) we thus isolate the 
popdy from its acts. The function constitutes no more a 
part of the organ the forma, than does the name by which 
we designate it. ‘When forms which evidently manifest 
one nature as to analogy of composition and structure are 
to be compared, their several functions and names need 
not here attend them. The body is the ens, and as such 
is to bear comparison with an homologous ens, notwith- 
standing the name or sound by which we may choose to 
difference them. When we are to compare two forms 
which manifest a common analogy together with a propor- 
tional variety, such structures are not to be differenced by 
either the function or the name, though one of those 
structures be known as the hand of an ape, and the other 
as the palm of a dolphin. And in the same way, when we 
shall examine the law of skeleton formation by the con- 
dition of symmetry, we shall do so, regardless, for the time, 
of either names or functional differences. 
* Anatomists have always admired the beautiful law of symmetry which presides over the development of all skeleton formations, however 
varied these may be as to quantity. The bilateral symmetry is that which has struck their attention more forcibly when regarding the skeleton 
figures. But it is also true that we find in several skeleton axes certain forms which manifest an antero-posterior as well as bilateral symmetry, a 
fact to which we shall hereafter call attention. Symmetry, according to Bichat, distinguishes the organs of animal from those of organic life (see 
Recherches sur la Vie et la Mort), whereas the law of symmetry, as described by Flourens, characterises both orders of organs : “ La loi générale est 
la symétrie.”’—See Htudes sur les Lois de la Symétrie, &c., Memoires d’ Anat. e de Physi. comp., tom. i, p. 1: Paris, 1844, 
