722 FUNGI 



' Pickling ' processes, however, are said by many to reduce smut 

 in wheat, rye, and oats, and is believed to be effective against the 

 attacks of ' covered ' smut ( U. Jensenii Rostr.) in barley : it does 

 not, however, diminish the ' naked ' smut ( U. nuda Jens.) in 

 barley so satisfactorily. According to some authorities the chlamy- 

 dospores of the latter species of smut are blown at the time of 

 flowering in between the glumes, and are thus securely protected 

 from the direct action of any poisonous compound which only 

 wets the outside of the grain. 



(d) Another method which is destructive to the 'smut 'and 

 which does not so seriously diminish the germinating capacity 

 of the grain is the following : — 



Soak the grain for 1 2 to 1 6 hours in a J per cent, solution (| lb. 

 in 10 gallons) of copper sulphate. Then run off the solution of 

 copper sulphate and pour over the grain a solution of milk of lime 

 made by adding 7 lbs. of good quicklime to 10 gallons of water. 

 Stir the grain in the lime-water for five minutes, after which 

 remove it and spread it out to dry before sowing. 



(e) Soaking the seed in a '2 per cent, solution of formalin for 

 two hours is recommended as a cheap and efficient remedy for 

 many of the smuts of cereals. 



Ex. 289. — Examine the smutted ears of the common cereals, wheat, barley, 

 and oats. 



As soon as one diseased ear is noticed, examine the others growing from 

 ' tillers ' of the same plant. 



If some of the ears are still in the leaf-sheath, open the latter and see if 

 these young ears are already smutted. 



In which part of the ear, the lower or upper half, is the smut first observable ? 



Ex. 290. — Examine in water with a high power the chlamydospores of the 

 various species of smut. Draw a single spore of each. 



Ex. 291. — Keep some smutted ears of the different cereals through winter, 

 and in spring place some of the chlamydospores of each in separate drops of 

 water on glass slides. 



Put these all under a bell-jar on damp blotting-paper. Examine with a low 

 power every twelve hours. 



When the spores have germinated, place over the drop of water a thin cover- 

 slip and examine with a high power. Make drawings, and contrast and compare 

 the conidiophores and conidia developed from each species of chlamydospore. 



Ex. 292. — Dip 50 grains of wheat in water, and then thoroughly dust them 



