ON MIMICRY IN FUNGI. 
3 
say the least, of the existence of a bisexuality in the hymenia of 
agarics, in which he regards the spores as the female element, and 
cystidia as the male. Now if subsequent observation should 
confirm this important discovery, which no one has as yet dis- 
proved, or even seriously called in question, we at once obtain a 
clue to the advantages likely to accrue to fungi from the visits of 
insects and the consequent interchange of reproductive elements. 
If insects can carry pollen from the anthers of phanerogams, they 
can assuredly carry the spores or spermatiaof cryptogams. 
But in the event of the sexuality of the Hymenomycetes being 
disproved, there remains another fact in connection with the 
germinative energy of fungus spores, and the vitality of certain 
species which must be born in mind. On the first appearance of a 
fungus in a new locality, it often grows with great vigour, and 
occurs in great abundance, but in the course of a few years it 
gradually declines, and may disappear altogether. To take a 
recent example, Puccinia malvacearum , Corda, was described and 
figured by Corda,* in 1854 ; and also by Montagne,f in 1856, from 
Chili. In June and July, 1873, it appeared for the first time in 
this country, and in the course of a short time devasted our holly- 
hocks, and also spread to our common species of Malva to such an 
extent that in the autumn scarcely a plant of M. sylvestris could 
be found without its foliage being destroyed by the fungus. At 
the present time it is by no means so common a fungus, and our 
gardeners have ceased to dread it as “ the hollyhock disease.” 
Puccinia Apii, Corda, is another instance. This fungus appeared 
first in this country in the autumn of 1866-7, on the cultivated 
celery, causing much mischief to the plant. We never see it now 
upon the celery in gardens, although it is occasionally met with 
upon the wild celery {Apium graveolens). 
It is well-known to practical brewers that by using yeast over 
and over again its efficacy becomes impaired to such an extent 
that it becomes useless. Under these circumstances, according to 
an established custom of the trade, an exchange of yeast with some 
other brewery is effected. Why a yeast which is languid in one place 
should in another, where it is apparently grown under exactly the 
same conditions, become active, it is difficult off-hand to say, but 
the fact remains that a change of locality does invigorate the 
growth of fungi. 
Although instances of agarics, simulating their surroundings, in 
appearance are comparatively few, yet many of the larger Pezizce 
do this. In turning over the plates of Cooke’s Mycographia I was 
struck by this. Now the Pezizce, compared with agarics, enjoy a 
great immunity from insect depredation, and the manner in which 
the Elvellacei disseminate their spores seems to be connected 
with this. The sporidia of the larger Pezizce are expelled by 
* “ Corda leones,” vi., p. 4, t. i., f. 12. 
t “ Montagne Sylloge.,” p. 314. 
