530 
AMERICAN JOURNAL OF BOTANY 
[Vol. 9, 
Schmitz, J. 1842. Mycologische Beobachtungen als Beitrage zur Lebens- und Ent- 
wickelungsgeschichte einiger Schwamme aus der Klasse der Gasteromyceten uhd 
Hymenomyceten. Linn. 16: 141-215. Pis. 6, 7. 
Trog, J. B. 1837. Ueber das Wachsthum der Schwamme. Flora 20: 609-618. 
Walker, Leva B. 1919. Development of Pluteus admirahilis and Tubaria furfuracea. 
Bot. Gaz. 68: 1-21. Pis. 1-5, figs. 1-8. 
DESCRIPTION OF PLATES 
Plate XXVIII 
Buttons of Agaricus campestris vars. Bohemia and Columbia. 
Figs. 1-16. Stages in development of fresh carpophores showing the young gills 
attached to the fundamental tissue below the pilear region. Figs. 4, 9, 13, 14, and 15 are 
tangential sections, showing no annular gill cavity and the small gills still attached to the 
tissue which will develop into the annulus. Photographed 5 to 20 minutes after free-hand 
sections were made. X 2|. 
Figs. 17-22. Young buttons which have turned brown and died 48 to 96 hours after 
their appearance on the substratum. Longitudinal sections show no annular gill cavities, 
but the gill Anlagen are attached to the fundamental tissue below them. Photographs 
made from buttons 5 to 20 minutes after being sectioned free-hand. X 3. 
Figs. 23-28. Dead buttons of the same stage of development after having been in a 
chrom-acetic solution for 24 hours show no annular gill cavities; the rifts below the young 
gills were caused by cutting the fluid-soaked buttons. X 3. 
Figs. 29-34, Fresh, actively growing buttons sectioned longitudinally after being 
sxposed to Flemming's weaker solution for 48 hours; the so-called annular gill cavities 
appear and the young gills appear to be growing downward into them. Photographs were 
made from 5 to 20 minutes after removal from fluid. X 3. 
Figs. 35-41, Young, actively growing buttons which were subjected to a chrom-acetic 
solution for 2 hours show exceedingly large annular gill cavities below the developing lamel- 
lae, Fij ures 35, 38, and 40 are tangential sections showing the so-called annular gill cavity 
as a wide slit due to the shrinkage of the tissue caused by the fixing agent. X 3. 
Figs. 42-44, Actively growing buttons, after being fixed in Flemming's strong solu- 
tion 6 to 18 hours, show shrinkage which causes the development of the annular gill cavity. 
Figs. 45-51. Fresh buttons after having been fixed for from 6 to 18 hours: figure 45, 
in Gilson's solution; figure 46, in Juel's; figure 47, in Bouin's; figure 48, in Merkel's; 
figure 49, in Kaiser's; figure 50, in picro-acetic; figure 51, in Carnoy's. All X 3. All 
show tremendous shrinkage, which accounts for the appearance of the annular gill cavity. 
Plate XXIX 
The microphotographs on this and the following plates were made with the aid of the 
Zeiss microphotographic apparatus and Leitz objectives nos. 3 and 6, and oculars nos. i, 
3, and 4. 
Figures 52 to 62 represent sections of Agaricus campestris. 
Fig. 52. Longitudinal tangential section of a young dead carpophore, showing the 
trama of the young lamellae continuous with the fundamental tissue below the pileus and 
forming a series of interlamellar chambers. Ocular i, objective 3, bellows 20 cm. 
Fig. 53. A dead button slightly older than the one shown in the previous figure, cut 
tangentially to the long axis of the carpophore; it shows wide tramal tissue and the hy- 
menia. The trama is continuous with the fundamental tissue below. Ocular 3, objective 
4, bellows 20 cm. 
Figs. 54, 55. Longitudinal tangential and median sections of a young dead button 
slightly older than the one shown in figure 53. The hymenial surface is beginning to 
