THE ANAT03IY OF A MLSH1103M. 
399 
subject which requires elucidation, and when we have ascer- 
tained the mode of growing agarics of any species, ad libitum^ 
from the spores, it Avill be comparatively easy to determine 
whether a kind of prothallus is formed on which germ and 
sperm cells are developed, cis in some other cryptogams, or 
whether the plant at once rises from the mycelium witliout any 
such intervention. 
EXPLANATION OF PLATE. 
Fig. 1. A^oimg mushrooma (Agaricus campe.tri^ springing from the 
mjcelium or spawn. 
„ 2. Longitudinal section of young mushroom with indication of future 
gills. 
3. Longitudinal section of mushroom in a more advanced condition. 
„ 4. Diagramatic shetch of portion of the hymenium of mushroom, 
showing arrangement of the gills. 
„ 5. Fragment of hymenium of an agaric ( GoinpJiidius'), showing a sterile 
cells, h hasidia, c cystidium, magnilied highly. 
„ 0. Longitudinal section of mature mushroom (Agaricus campcstris), 
a mycelium, h stem, c veil or ring, cl pileus or cap, e gills, 
covered with the hymenium. 
„ 7. Portion of hymenium of meadow mushroom (Agaricus arvcnsis), 
seen Irom above, with the spores in situ, magnified. 
„ 8. Portion of stem of mushroom, highly magnified. 
„ 9. Spores of mushroom (Agaricus campestris) , more highly magnified. 
„ 10. Transverse section of stem of Agaricus campestris with its pale, 
pith-like centre. 
„ 11. Archegonium and cylindrical branch-cell from Agaricus vaginatus, 
highly magnified. After Karsten. 
„ 12. Two naked archegonia from the same agaric, highly magnified. 
After Karsten. 
„ 13. Transverse section of gills of mushroom. 
,, 14. Transverse section of gill of mushroom (Agaricus ca^npestris), 
showing arrangement of hymenium with its hasidia and spores, 
and central cell-structure descending from the pileus, highly 
magnified. 
D D 
VOL. VIII, — XO. XXXIII, 
