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PHARMACEUTICAL BOTANY 
Sub-class A.—Zyygomycetes 
(Sexual apparatus shows isogamy) 
Order 1.—Mucorales, the black molds, mostly saphrophytic. Ex¬ 
amples: Mycor Mucedo, Rhizopus nigricans , Thamnidium,Pilobolus. 
Rhizopus nigricans (Mucor stolonifer), commonly known as 
“ Black Mold ” or “ Black Bread Mold,” is frequently found on bread, 
jellies, syrups, acetic pharmaceutical extracts and other substrata, 
where it forms a dense thready mycelium bearing numerous black 
tiny spore cases. The source of this mold is the spores, which are 
found in the air or water with which the attacked substratum is 
Pig. 123. —Black mold (Rhizopus nigricans). A , older plant; myc, mycelia; spx 
sporangiophore; sp, sporangium; st, stoloniferous hypha produced by A, and 
giving rise at its tip to a new plant, B. Greatly enlarged. (Gager.) 
in contact. Each of these, upon germinating, sprouts out and forms 
three kinds of hyphae, vix.: rhizoidal or submerged hyphce, spor- 
angiophores or aerial hyphce and stoloniferous hyphce. The branching 
rhizoidal hyphae penetrate the substratum and secrete a dias- 
tatic ferment that changes the water insoluble carbohydrate ma¬ 
terials into a soluble sugar which passes into solution and is absorbed 
by their walls. This, upon entering the hyphae, is converted into 
protoplasm, and so the mold increases in size. Sporangiophores 
or aerial hyphae arise vertically or obliquely from a bulged-out 
common base of the rhizoidal hyphae. Each of these when mature 
