DESMIDS AND DIATOMS. 589 
is not a single indivisible being, but a community of indi- 
viduals, each of them a potential plant, living, it is true, 
in intimate connection with others of its kind, but equally 
capable of living alone, when, with proper care, its con- 
nection with these latter is severed. Every plant, as it 
buds in spring, is but reproducing hundreds or perhaps 
thousands of new individuals, similar in every respect to 
that which originally sprung directly from the seed. Un- 
like what is seen in the Animal Kingdom, the higher as 
well as the lower orders share equally in this peculiar 
mode of growth; with this difference, however, that while 
among the higher groups the newly formed parts retain 
their connections, and become a portion of a compound 
structure, in the humbler groups they often separate as 
soon as formed, and acquire a distinct and independent - 
existence. 
Let us now observe some of the results of this process, 
as illustrated in the minute forms of vegetation to which 
this paper is more especially devoted. 
In the last number of the Natura ist it was shown, 
that, among the Desmids and Diatoms, though “ conjuga- 
tion” and the formation of seed-like bodies or spores 1s a 
normal mode of reproduction, yet here, as among higher 
plants, multiplication by this method is comparatively 
unimportant, by far the greater number of individuals 
arising from the self-division or fission of a single cell. 
So true is this, indeed, that the former mode, although 
probably true of all, has as yet been observed in but very 
few, and those the least remarkable species, while the 
process of budding or self-division is universal. ` Indeed, 
it is scarcely possible to examine a recent gathering of 
Diatoms, in which individuals will not be found illustrat- 
ing all the different stages of development, from those in 
