No. 38.] 
[December, 1877. 
A QUAETEELY EECOED OF CEYPTOGAMIC BOTANY 
AND ITS LITEEATUEE. 
DR. NYLANDER ON GONIDIA AND THEIR 
DIFFERENT FORMS. 
Translated hy The Rev. J. M. Crombie, F.L.S. 
In the ‘‘Flora,” 1877, No. 23, pp. 353-859, Dr. Nylander has 
made some valuable observations on this subject, which may be 
regarded as one of his most important contributions towards the 
solution of the “ Lichen-Gonidia ” question, and which so clearly 
prove the erroneousness, not to say absurdity, of the Schwendenerian 
hypothesis that, in the general interests of Botanical science, they 
may with great propriety be placed before the readers of 
“ Grevillea.” In the copy of the paper sent me by Nylander, 
there are a few additional notes communicated by him, in writing, 
which I have duly indicated in what follows by these marks [ ]. 
I. — Gonidia in Connection with the Neighbouring Parts of 
THE Thallus. 
There are different modes of existence which subsist between the 
gonidia and the internal surrounding thalline elements, according 
as the thalli themselves are either' — 1st, closed, involved in a con- 
tinuous cortical stratum; or, 2nd, not closed, that is, where the 
cortical stratum is wanting (which, for example, takes place 
in pulverulent thalli). In the former case (in corticated 
thalli), the gonidia usually occupy a narrow proper stratum in the 
lower portion of the cortical stratum, or in the upper portion of 
the medulla; and there, being freely disposed amongst the radicles 
of the MyelohyphaB, they cannot be multiplied unless by slow 
division. On the contrary, in the other case (in ecorticated thalli), 
in leprose and analogous thalli, free gonidia are copiously present, 
and are most readily propagated by repeated divisions. Evidently 
soredia present a state of gonidia in those points similar to pulver- 
ulent thalli,* 
* An excellent example, that soredia are endowed with tbe faculty of 
creating propagula may be seen in the “ Flora,” 1875, p. 8. 
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