BERKELEY, ON CRYPTOGAMIC BOTANY. 183 
chemical substances, do not prevent the growth of moulds. One form 
proves an intolerable nuisance in electrotyping, being developed in the 
solution of copper used in that process, and becoming itself eventually 
thoroughly electrotyped. Under such circumstances, they have the power 
of separating the metal or other noxious principle, while they avail them- 
selves of any nutritive matter with which it may be combined. ‘These fluid- 
born states of Penicillium, and other more or less allied Mycelia, are often 
regarded as Alge, but they have no affinity with those vegetable pro- 
ductions. 
“One genus of moulds was long considered as peculiarly destructive to 
living vegetable tissues, and the grape mildew, peach mildew, blane de 
rosier, &c., are all attributable to it; but it has already been shown that 
these supposed species of Oidiwm are not true moulds, but merely states of 
different species of Zrysiphe. This is, however, not the case with that class 
of moulds which belong to the old genus Botrytis, or to Corda’s genus or 
subgenus, whichever may be the more correct term, Peronospora. These 
moulds run, by means of their mycelium, amongst the loose tissue of the 
leaves, and at length protrude fertile branches through the stomates. 
Tulasne, Caspary, and others, have lately discovered that there is another 
form of fruit, with far more complicated and larger spores developed at the 
base of the fronds. The genus Artotrogus of Montagne very probably in- 
cludes such forms of fruit. But not only are they destructive to vegetable 
tissues. Where they penetrate into the intimate organs, as in the case of 
the silkworm and several other insects, they soon produce death. The 
muscardine, which is caused by Betrytis Bussiana, is capable of being pro- 
pagated by inoculation, or even without any injury of the tissues the mere 
ae of rubbing a few spores upon the body is sufficient to propagate the 
isease.” 
Our long extracts will afford a good example of the style and 
matter of the book. They also indicate the value we attach to 
its contents. However much we might be tempted to criticise 
some of Mr. Berkeley’s views, the present general notice of 
the work is not the place. Our estimate of his labours will be 
found in our most cordial and earnest recommendation of it 
to all who are engaged in the study of the lower forms of 
plants. Every one who possesses a microscope, and wishes to 
make his observations upon the innumerable forms of vege- 
table organisms by which he is surrounded available for the 
purposes of science, cannot do so more effectually than by 
making himself master of the contents of this valuable intro- 
duction to Cryptogamic Botany. 
