STRUCTURE. 23 
dium, and hypertrophied basidium ; these are the three elements 
which form the hymenium.’’* 
The only reproductive organs hitherto demonstrated in Agarics 
are the spores, or, as sometimes called, from their method of 
production, basidiospores.t These are at first colourless, but 
afterwards acquire the colour peculiar to the species. In size 
and form they are, within certain limits, exceedingly variable, 
although form and size are tolerably constant in the same 
species. At first all are globose; as they mature, the majority are 
ovoid or elliptic; some are fusiform, with regularly attenuated 
extremities. In Hygrophorus they are rather irregular, reniform, 
or compressed in the middle. Sometimes the external surface is 
rough with more or less projecting warts. Some mycologists 
are of opinion that the covering of the spore is double, consist- 
ing of an exospore and an endospore, the latter being very fine 
and delicate. In other orders the double coating of the spore 
has been demonstrated. When the spore is coloured, the exter- 
nal membrane alone appears to pos- 
. en 
sess colour, the endospore being con- =A ane Ga 
i“ in, by 
Ty fi 
~~ ‘th, i Ww ‘ 
Wm, 
stantly hyaline. Itmay be added here, 
that in this order the spore is simpls 
and unicellular. In Lactarius and 
Russula the trama, or inner substance, 
isvesicular. True latex vessels occur 
occasionally in Agaricus; though not 
filled with milk as in Lactarius. 
Potypore1—lIn this order the gill 
plates are replaced by tubes or pores, 
theinterior of which is lined by the |, cies 
hymenium ; indications of this struc- duced). 
ture having already been exhibited in some of the lower 
™ Cooke, M. C,, ‘‘ Anatomy of a Mushroom,” in ‘‘ Popular Science Review,” 
vol. viii. p. 380. 
+ An attempt was made to show that, in Agaricus melleus, distinct asci were 
found, in a certain stage, on the gills or lamellae. We have in vain examined the 
gills in various conditions, and could never detect anything of the kind. It is 
probable that the asci belonged to some species of Wypomyces, « genus of para- 
sitic Spheeriaceous fungi. 
