264 BOTANICAL GAZETTE [ocroBER 
OERSTED?’ says that the stem is produced first, and afterward the 
pileus. 
In the forms of Agaricus campestris studied here, as I have shown, 
the young homogeneous fruit body (figs. 1, 2) shows no differentia- 
tion into parts (except the rudimentary universal veil), and it is to 
be considered as the primordium of the carpophore, It is not 4 
stem, nor is it a pileus, there is no differentiation to show even the 
rudiments or primordia of stem or pileus; there is no more active 
growth manifest in one place than in another, and no separate group 
of hyphae with richer protoplasmic content which gives a differen- 
tial stain. It cannot therefore be considered as a rudimentary stem, 
as GOEBEL (/, c, 132-138) has suggested. It is true we might speak 
of a stem end and a pileus end, but the application of these terms to 
the portions of the carpophore primordium which are later to be 
organized into pileus and stem primordia does not predicate their 
existence before organization takes place. But soon the differentia 
tion takes place by the appearance of the primordium of the hymenium, 
which at once delimits also the primordia of pileus, stipe, and ame: 
ginal veil (figs. 3-5). This condition answers well to the conception 
of Fries that all parts are present in the young stage, though he 
conceived them to be present in the still younger stages, which we 
find is not the case, 
DECANDOLLE* says that in the case of Agaricus the upper A gs 
or pileus develops before the lower part, or stipe. Without critical 
study of the very young stages one might be led to this conclusion 
by an examination of certain large pileate short-stemmed is 
and perhaps DECANDOLLE examined such plants. According to 
Fayop (I. c. 279-280) the pileus is differentiated first, the hymemum 
23 OERSTED, A. S.: Iagttagelser anstillede i Lébet af Vinteren 1863-64, som cast 
ledet til Opdagelsen af de hidtil ukjendte Befrugtningsorganer hos Blapsvampen® 
Oversigt over det Kongelige danske Videnskabernes Selskabs Forhandlinget, P- a 
pls. I-2. 1865. Copenhagen. 
See translation, Observations made in the course of the winter 0 
have led to the discovery of the hitherto unknown organs of fructification in the ¢ 
cini by A. S. OERSTED. Quart. Jour. Microscop. Sci. 8: 18-26. 1868. o 
24 “Dans plusieurs, tels que les Agarics, la partie supérieure, qu’on ore” 
chapeau, parait développée avant l’inférieure, qu’on a comparée & une tige 0 fs 
pédoncle; l’inverse semble avoir lieu dans les Clavaires qui paraissent on 
en haut.” Organographie végétale 1:384. 1827. 
£ 1863-64, which 
