TYPES OF CRYPTOGAMS; THALLOPHYTES 257 
305. Classification of Types studied. 
DIATOMACE. Yellowish. 
Diatoms. 
CYANOPHYCE. Blue-green or some similar color. 
Oscillatoria. 
CHLOROPHYCE. Green. 
Pleurococcus, Spirogyra, 
Vaucheria, Nitella. 
PH#OPHYCE. Olive. 
Fucus. 
FLORIDES. Red. 
Nemalion. 
Polysiphonia. 
THE STUDY OF BLACK MOULD (RHIZOPUS. NIGRICANS) 
306. Occurrence. —This mould may be found in abundance on 
decaying fruits, such as tomatoes, apples, peaches, grapes, and cher- 
ries, or on decaying sweet potatoes or squashes. For class study it 
may most conveniently be obtained by putting pieces of wet bread 
on plates for a few days under bell-jars and leaving in a warm place 
until patches of the mould begin to appear. 
307. Examination with the Magnifying Glass.— Study some of — 
the larger and more mature patches and some of the smaller ones. 
Note : 
(a) The slender, thread-like network with which the surface of 
the bread is covered. The threads are known as hyphe, the entire 
network is called the mycelium. 
(6) The delicate threads which rise at intervals from the myce- 
lium and are terminated by small globular objects. These little 
spheres are spore-cases. Compare some of the spore-cases with 
each other and notice what change of color marks their coming to 
maturity. 
308. Examination with the Microscope. — Sketch a portion of the 
untouched surface of the mould as seen (opaque) with a two-inch 
objective, then compare with Fig. 189. 
