SOCIETY OF CENTRAL ILLINOIS. 273 



Mr. Gray — I have had this same experience with Mammoth 

 Cluster and Doolittle. The fungus first made its appearance 

 after a very heavy crop. I did not get a bushel off of three 

 acres. The Snyder Blackberry suffered the same way. I think 

 I shall be compelled to give up growing cane fruit for two or 

 three years. The Miller cricket has been a great pest in my 

 raspberry plantations. 



Mr. Doan — After two or three heavy crops, plantations become 

 exhausted, and are liable to be attacked by this fungus, but if 

 heavily manured or mulched, are more likely to escape. 



THE LIFE OF AN APPLE TREE. 



BY F. I. MANN, OILMAN. 



In the present condition of apple tree growing, it would be 

 well for us to consider some things in its construction other than 

 the apparent surroundings and conditions. That our so-called 

 varieties undergo change in certain characteristics as they become 

 older, I think can hardly be denied, and it is important that we 

 investigate some of the causes which lead to these changes. 



"Whatever definition we may give to life, or however we may 

 consider it, the element of greatest importance is the tendency to 

 continue existence. A new life may be born, but if it has not in 

 itself the desire or tendency to continue its existence sufficiently 

 strong, the life is given up. This tendency to continue existence 

 is termed vitality, but we should not confine this use of the 

 term with the one simply meaning thriftiness or an apparent life 

 force. The thriftiness may be due only to perfectness in envi- 

 ronments, and not to any strong tendency to exist. It is not 

 necessary here to consider any of the causes that modify this ten- 

 dency to exist in the reproductions of the new individual, such as 

 the conditions that would give strong vitality, or the contrary. 

 It is sufficient for our present purpose to consider that every new 

 life has a normal amount of vitality, or tendency to continue its 

 existence for a somewhat certain period of time, known as the 

 period of longevity. A child is born with a tendency to live 

 three score and ten. Its environments largely determine whether 

 it lives so long. But we could not consider that it had any ten- 

 dency to live for two hundred years, whatever its environments 

 might be. So we may consider the horse as having a tendency to 

 live for a score of years; the kine, sheep and swine, each its own 

 period of life; the clover, with continuance of but two years, and 

 other plants and animals having their own period of longevity, 

 ranging from a century and more down to but a few moments. 



Life is a property only of an individual. It is something that 

 is brought into existence only through the production of a new 

 —19 



