268 D, D. CUNNINGHAM. 
escape detection in developing or recently formed sporangia, 
which have been kept in a very moist atmosphere; it is very 
soft, and quickly dissolves and disappears in water, although 
readily visible ere the addition of fluid, and especially so long as 
no pressure has been applied. In such cases, too, certain re- 
agents, such as Liquor Lodi, readily demonstrate its existence. In 
older sporangia, which have undergone a certain amount of dry- 
ing, it appears as a distinct, somewhat resistant, and very elastic 
membrane, of a yellowish colour. In structure it is finely mole- 
cular, and the external surface is covered with projecting organic 
corpuscles (Pl. XVIII, fig. 6). In the course of thorough 
desiccation again, it appears gradually to disintegrate and more 
or less completely disappear, leaving its contents exposed, and 
only adherent to one another by intercellular material. Its inner 
surface is sometimes distinctly mapped out by a series of promi- 
nent thickened ridges into polygonal areas corresponding with the 
formative Aincebe (ig. 17). 
Fie 17.—Ridges and uepressions on inner surface of Sporangial membrane 
x 1000. 
After the sporangia have been, as it were, planned out by the 
aggregation and more or less intimate union of the Amebe, and 
the formation of an investing membrane, the process of spore 
formation normally sets in. When this is regularly carried out 
the bodies of the Amcebz become resolved into masses of spherical 
spores, measuring from 5 to 9 » in diameter. In cases where the 
fusion of the parent bodies seems to have been complete these are 
indiscriminately massed in the cavity of the sporangium embedded 
in an intercellular basis ; where, on the other hand, the process 
has not gone so far they tend to adhere in groups of various sizes 
corresponding to individual Amcebz, or to small groups of these. 
The intercellular material in recently developed sporangia is 
soft and seemingly more or less fluid, resembling the intercellular 
