— 4 
AND 8PORES IN AGARICUS CAMPESTRIS. 169 
some 200 species, paid special attention to this question, and says 
that in Agaricus campestris he had never seen a basidium with 
more than two sterigmata, and never any signs of two crops as 
described by W. G. Smith. 
De Bary, writing in 1887 *, observes that there are only two 
sterigmata in Calocera and Dacryomyces, but does not mention 
the mushroom. The next writer to touch upon the question was 
Mr. G. Massee, who, in a note to a “ Monograph of the Thele- 
phoree” + referring to Sachs’s statement that only two spores are 
developed in the mushroom, remarks :—‘ This is not correct ; 
the basidia of Agaricus campestris have four sterigmata, each 
producing a spore; nevertheless this strange error has been 
repeated and accompanied by the equally incorrect woodcut in 
several English works on Botany.” Finally, Zopf in Schenk’s 
‘Handbuch,’ in 1890, states (vol. iv. p. 631) that in Agaricus 
campestris there are only two sterigmata. 
Most of the material at my disposal consisted of cultivated 
mushrooms of different ages. Small pieces bearing lamelle were 
cut off and fixed for about 24 hours in Flemming’s weak solution, 
orin a concentrated solution of corrosive sublimate containing 
one per cent. of glacial acetic acid. Flemming’s solution was 
found to give far better results than corrosive sublimate. After 
fixation, the material was well washed in water and brought 
gradually through increasing strengths of spirit to absolute 
alcohol; then through 50 per cent. aleohol and chloroform, 
through several changes of chloroform to half chloroform and 
paraffin, and finally to paraffin. Thin sections were then made by 
the Cambridge Rocking Microtome, and after being floated out on 
the surface of warm water, they were fastened on the slide by 
M of albumen fixative. The paraffin, after careful drying, 
sli "rn by xylol, and the sections were then stained on the 
slong ori e principal stains used were gentian violet, either 
carmine, In combination with Congo red or fuchsin, Hartog s 
and nigrosin as recommended by Wagert, Manns 
*osin and toluidin blue, Heidenhain’s hematoxylin with orange G 
or Congo red. 
* 
à mp Morph. Fungi, &c., Eng. ed. 1887, p. 63. 
4 Soe, Journ. (Bot.) xxv. (1890) p. 107. 
4 & St 
p. 294 ructure and Reproduction of Cystopus candidus,” Ann. Bot. vol. x. 
