1906] ATKINSON—AGARICUS CAMPESTRIS 243 
BoNoRDEN® deals briefly with the anatomical structure of the 
genera recognized by Fries in his Epicrisis. He does not discuss 
the differentiation of the parts in the young fruit body, but describes 
somewhat in detail the different forms of the universal veil, its mode 
of dehiscence, and its relation to the partial veil and the pileus in 
certain species of Lepiota (pp. 178-181). He says, very briefly (p. 8): 
“From the mycelium rises the fruit body of the fungus (stroma, 
thallus), either naked from the first or enclosed in an envelop (velum, 
volva). The latter consists always of very much elongated cells, 
tubes, which are like the tissue of the mycelium, and has therefore , 
always a structure very different from that of the fruit body of the 
fungus; it is to be regarded as a continuation of the mycelium, The 
envelop is ruptured by the further growth of the pileus and is thrown 
off, but sometimes remains a part of the same and forms the epidermis 
of the pileus, on which account this is so different in structure in the 
case of the gastromycetes and pileated fungi from the other parts 
of the fungus.” 
H. Horrman contributed at that time some important work on 
‘the anatomy and morphology, and as early as 1856 gave a very 
brief account of the origin of the hymenium of A garicus campestris.” 
In speaking of his studies of the developmental history of the lamellae 
in very different types (J. c. , P. 145) he cites three extremes: Agaricus 
carneo-tomentosus (Panus torulosus), where they arise at the apex of 
the young fruit body; Agaricus campestris, where they originate 
deeper in the interior and develop laterally; and Hymenogaster 
klotzschii, where they remain concealed in the interior of the fungus. 
In describing the development of Agaricus campestris (p. 145) he 
Says (I give a free translation): “It begins, as BULLIARD has already 
very well represented (Champ. d. France. pl. 514, fig. L. 1791-1809), 
in the form of small spheres which for a part rest upon thick mycelium 
Strands, This stroma is formed as in the former case [A garicus 
carneo-tomentosus, the stroma of which, he says, at first quite homo- 
8eneous, is formed out of felted filamentous cells]. Gradually the 
same takes on an elongate form; the interior cells grow in a perpen- 
© Handbuch der Allgemeine Mycologie 147-196. 1851. 
ag ’ Pollinarien und Spermatien bei Agaricus. Bot. Zeit. 14:137-148, 153-163. 
+ 5. 1856. 
