8 PASTORAL AND AGRICULTURAL BOTANY 



LABORATORY EXERCISES 



1. Remove some of the mycelium with the conidiophores of Aspergillus fumigatus 

 from the surface of the bread in the Petri dishes with a pair of smooth forceps. Place 

 on a slide in 50 per cent, alcohol, so as to wet the hyphae. Drain off the alcohol and 

 mount in acetic acid (2 per cent.), applying a ring of asphaltum. Study and draw. 



2. Study and draw the awned brome grass, Bromus tectortim, and dissect out the 

 parts which collectively become injurious to animals. 



3. Do the same for the sand bur, Cenchrus tribuloidcs , and the squirrel grass, 

 Hordeum jubatum. 



4. Compare the three, or four, species of feather grass, Stipa capillata, S. comata, 

 S. spartea and make detailed drawings of the spikelets with attached spirally twisted 

 awns. 



5. Macerate portions of the crimson clover hair balls in potassium hydroxide dis- 

 solved in water in a porcelain evaporating dish over the Bunsen burner flame. Com- 

 pare the parts thus released with the hairs on the calyces of crimson clover flowers 

 preserved hi alcohol. Draw the material from the two sources for comparison. 



6. Remove the hairs from the leaves of plane trees and study under the microscope. 

 A supply of the leaves for this purpose should be gathered in the spring. Young leaves 

 of plane trees should be preserved in alcohol for later class study. 



