86 ZOOPHYTES. 
gemmation soon ceasing, except in certain shoots, at still longer inter- 
vals, which continue growing and lengthen out into large branches. 
This principle admits of some irregularity, arising from an unequal 
amount of nourishment, or a difference of exposure, but in general 
there is a remarkable uniformity. And it is due to this fact, that 
species have their specific characters displayed in their modes of 
branching; that some species spread widely, with long even branches, 
and others, with numerous crowded ramifications; and, moreover, the 
individuals of a species are alike in their general forms. 
This principle determines the distance of a lateral polyp from the 
apex of a branch, before it can commence to bud, as well as the dis- 
tance separating branches. The Gorgonia setosa, the subject of our 
illustrations, in § 74, is a beautiful exemplification of this subject, and 
well merits farther remark. In this species, the lateral polyps rarely 
bud and form branchlets nearer than six to nine inches from the 
apex,—eight inches is the average distance,—and, as there are about 
eighty polyps on the lateral surface to an inch in length, it follows, 
that generally more than six hundred polyps are situated above the 
first branchlet. And, moreover, as the branchlets are about a third 
of an inch apart on each side, polyps enough are added, by budding, 
to lengthen the apex correspondingly before another side-polyp buds, 
and another branchlet starts. 
What is here indicated, but that the process of budding exerts an 
inductive influence for some distance from the centre of action,—that 
there is a concentration of nutriment and of forces required, measured 
by the interval between the budding centres? In the Gorgonia, just 
alluded to, some hundreds of polyps are thus, in one sense, tributary to 
the budding polyps at the extremity; for, until the budding apex has 
grown beyond to a certain distance, one of the side-polyps, though 
ready to bud, cannot summon gemmating force enough to develope 
buds; but when the former is so far removed, that the required 
nutriment and vital force are supplied, then the excess, which goes 
on increasing, concentrates upon one of the side-polyps below. The 
lateral polyp, which becomes a new centre of gemmation, is a 
certain distance above the preceding branchlet, owing to the fact, 
that this branchlet exerts its influence for a short distance around 
itself, though already considerably elongated. ‘The same principle is 
illustrated even in the irregularities or apparent exceptions. When 
side branches form low on the stem, the intervals are often much 
larger than above stated, owing to the less amount of nutriment 
