588 LEGUMINOSÆ INDIGENOUS TO ` 
nosis valere potest et debet." But that is not at all a necessary 
consequence. It is now generally admitted that a very constant 
and important character in one order may be most variable, and 
therefore useless, in another. And in the present instance, the 
supposed differences in the number of nerves of the calycine teeth 
or divisions are fallacious. The calyx of Leguminose, as well as of 
Labiate, appears to be formed in general of five three-nerved 
leaves, and by the combination of the lateral nerves of adjoining 
leaves, or by their apparent evanescence, the total number of fif- 
teen nerves of the whole calyx is often reduced to ten, or to five, 
or to some intermediate number (as for instance thirteen in most 
Labiatæe-Satureineæ). Wherever these differences are owing to the 
complete combination or separation of the lateral nerves from the 
base of the tube, and when the whole of the nerves are of nearly 
equal thickness (as in the thirteen-nerved Satwreinee and the 
fifteen-nerved Nepetee), they have been found to be tolerably 
constant, indicative of modifications in the general symmetry of 
other parts of the flower, and accompaned by differences in habit 
and therefore important. But where the mid-rib of each leaf is 
prominent, and the lateral ones faint, the modifications of the 
latter are not only more vague and inconstant, but apparently of 
little or no consequence. Thus in Aspalathus the lateral nerves 
of each calycine leaf are almost always combined with those of the 
adjoming ones at the base of the tube (distinct only in a very 
few species, where they are faint and irregular) into one, which is 
usually forked near the top of the tube, and these forks run along . 
the margin of the teeth. They are very prominent when the 
teeth are broad and foliaceous ; scarcely perceptible to the naked 
eye, where the calyx is thick or fleshy; and confounded with the 
central nerve into one mass, where the teeth are slender; or concealed 
from the casual observer where the calyx is downy; but with 
care they may be traced in almost all Aspalathi, at least at the 
base of the teeth, and are very distinetly visible in many of the 
so-called dacinie uninerves. The prominence of these lateral 
nerves is, indeed, in some cases a good specific character, and even — 
is in some groups more frequent than in others, but cannot be — 
