amounts of acids and tannin indicates a non-performance of some of 

 the complicated processes of metabolism, which should carry off 

 these injurious by-products. The failure of the diastatic and oxidiz- 

 ing functions are symptoms of a similar nature. 



It therefore appears, so far as conclusions can be drawn, that this 

 " yellow " disease of the aster is due to a failure of those metabolic 

 activities in the leaf which when properly carried on furnish nutrition 

 for the plant. Further, it is believed that the characteristic effects 

 in the flower, which have been shown to be a change or reversion 

 from reproductiv^e to vegetative development, are simply a secondary 

 symptom and the result of partial starvation in those parts. The 

 actual, fundamental cause of all this is still unexplained, except that, 

 as stated, it is not due to individual circumstances, but is the result 

 of a misadjustment of the plant to what should be its normal envi- 

 ronment. The fact has been mentioned that there is a well-defined 

 variation in the amount of the disease in different seasons. It seems 

 not improbable that such circumstances as the'frequency of rainfall, 

 relations of rainfall to sunshine, and such conditions as would 

 strongly and suddenly affect the functions of the plant may be con- 

 cerned in the result. 



Finally it may be mentioned that this disease is one of an increas- 

 ing list of somewhat similar troubles. Most prominent of these is 

 the peach " Yellows." The '' Calico " disease of the tobacco is 

 another, in connection with which the researches of A. F. Woods of 

 the U. S. Department of Agriculture have given many suggestions 

 in the present work. 



THE ASTER RUST. 



A true rust affects the aster very commonly. This is seen in 

 orange-colored pustules which break out on the under side of the 

 leaves rather late in the season. While prevalent everywhere the 

 disease is not at all destructive and does no apparent damage to the 

 plant. 



THE BLACK BEETLE. 



One of the best known aster pests is the slender, lively black 

 beetle {Epkauta Petittsylvatiicd) which attacks the blossoms. If left 

 unchecked they soon destroy every flower when at all prevalent. 

 Thorough hand picking has been our best remedy and if done 

 every day is no great task even in a large bed. 



