TYPES OF CRYPTOGAMS; THALLOPHYTES 261 



Are they straight or curved ? Describe the margin, of the cup, the 

 color without, and the color of the contents. 



With a power of 200 diameters or more examine some of ths 

 cells composing the cup and note the form, color, and nature of the 

 surface. Draw. With the point of a needle or knife pick out a 

 bit of the contents of the cup and examine as above. Note the 

 characters as before and compare in detail with the cells of the cup. 

 The cells within the cup are the spores. Can you tell how they are 

 attached ? 



A thin section through the cup will show the mode of attachment 

 and the r.elation of the spores to the cup. 



312. Examination of Red and Black Rust. — Under the magnify- 

 ing glass examine the eruptions of spores (sori) on the wheat plant, 

 some of red spores and some of black spores. The red spores are 

 faded in dried specimens. Note the approximate size and shape 

 and any other peculiarities. Prepare slides of each kind of spores 

 and see if both can be found in one sorus. The spores may be 

 taken from the host-plant on the point of a knife by picking rather 

 deeply down into the sorus. Place the small quantity of spores so 



Fig. 192. — A Cluster-Oup of Anemone Eust (Puccinia fnsca). (x 120.) 

 «, chams of spores ; j>, tlie covering or peridium of the cup j A, byphse. 



obtained in a drop of water on a slide, spread with dissecting needles 

 and cover. Examine under a power of 200 or more diameters. 



The red spores (uredospores) have each a stalk from which they 

 easily fall. They may be seen attached to their stalks if properly 



