I9I9] 



MCDOUGALL—STROPHARI A 



259 



development, since the carpophore shown in fig. 2 is considerably- 

 larger, although little if any further developed than that shown in 

 fig. I ; but in any case the first internal differentiation is the appear- 

 ance of the hymenophore primordium. 



The rapid growth of the elements of the hymenophore as the 

 carpophore enlarges, together with the cessation of growth, or at 

 least very slow growth of the ground tissue below the hymeno- 

 phore primordium, soon cause the formation of an annular gill 

 cavity (figs. 3, 4). The presence of the annular gill cavity makes 

 it easy to see in longitudinal section which parts of the carpophore 



"'MS^^W 



Fig. I 



Fig. 2 



Figs, i, 2. — Stropharia epimyces: fig. i, small carpophore showing primordium 

 of hymenophore as only dififerentiation ; fig. 2, larger specimen at same stage of devel- 

 opment. 



in general belong to the pileus fundament and which to the stem 

 fundament, but it is not until still later that these are clearly dis- 

 tinguished. 



The gill cavity enlarges rapidly (fig. 5), but it does not become 

 very large before the formation of the lamellae by the downward 

 growth of hyphae from the hymenophore begins (figs. 6, 7). By 

 this time also, if not earHer, the universal veil has disappeared, 

 and the mature carpophore is without any trace of it. Atkinson 

 (4) has explained in detail the development of the lamellae in 



