107 
“T must pass over monstrosities arising from hypertrophy, although many 
interesting examples may have been given, but they present no special difficulty as 
to their cause, and the same may be said of those produced by atrophy. The cellar 
Polyporus exhibited this evening is an example of both of these causes combined— 
hypertrophy having caused the enormous elongation and multiplication of the 
stems, and atrophy having reduced the pilei to insigificant dimensions. 
‘* Before concluding my remarks, I must call attention to two very curious 
and perplexing monstrosities of which I am unable to give any satisfactory ex- 
planation. Mr. Worthington Smith described and figured* a plant of Agaricus 
campestris (fig. 28) which had on the top of its pileus a reversed pileus (quite half 
the size of the parent) from which ascended a stem duly furnished with a ring, and 
surmounted by another pileus with the gills downward. It is possible to account 
for the reversed pileus and stem by adhesion, as in cases already referred to under 
that head, but not so the uppermost pileus. I venture to submit to you the only 
explanation I can think of. Let us number the three pilei, calling the lower No. 1, 
the one reversed No. 2, and the top one No. 3. Supposing No. 2 to have been pressed 
by an accident of growth against No. 1, adhesion would take place, and No. 2 
would be drawn from its attachment by the more vigorous growth of No. 1, and 
hoisted upside down so that its stem would be in the air. This stem would then 
reverse its direction of growth, and proceed to form a new pileus on its upturned 
extremity, deriving its nourishment from the tissue of No. 1, with which it had 
become perfectly united. 
**The same gentleman represents an Agaricus fascicularis, the pileus of which 
extends beyond the normal gills, bends downwards, and then takes an almost 
horizontal direction towards the stem (fig. 24). On the portion extending beyond 
the normal gills, another series of gills is formed, and again on the opposite surface 
is a third series. These several series may be the result of interrupted and re- 
newed growth, or may be another curious instance of prolification. 
“*No one has ever yet observed, as far as I know, a case of adhesion between 
two individuals of different species. I exclude cases of parasitism. 
“T have thus glanced at a few of the more typical examples of monstrosities 
amongst the higher Hymenomycetes, and would conclude by expressing the hope 
that mycologists will regard this subject as one worthy of more extended study, 
and pass over no specimen they may find without making careful notes and obser- 
vations. 
* Gardeners Chronicle, July, 1873. 
