MICROSCOPIC ORGANISMS IN INTESTINAL CANAL, 269 
matter within Mucor sporangia. Like the material of the 
sporangial wall, however, it concretes or sets in drying, so as to 
appear in many preparations of partially dried sporangia in the 
form of a network, in the interspaces of which the spores are 
situated. The character and definition of this vary considerably 
in different instances, and in some cases it may be distinctly 
resolved into two series of meshes—a larger one, seemingly cor- 
responding with the parent Amcebe, and a smaller one with the 
individual spores (Figs. 18. 19). Both the sporangial wall and 
Fie. 18.—Large reticula of intercellular matrix x 1000, 
the intrasporangic network are, when fully developed, stained of 
a deep red brown by solutions of iodine, whilst the spores merely 
Fic. 19.—Fine reticula of matrix corresponding to spores x 1000. 
acquire a yellow tint. No blue colouration follows treatment 
with iodine and sulphuric acid, nor does any effervescence occur 
under the influence of acids. 
The spores, as before mentioned, are, when first formed, of a 
spherical outline, or are, at all events, spherical when free, for, 
due to mutual pressure, they are frequently more or less polygonal 
while within the sporangium. ‘The process of spore formation 
