PEACH AND THE PEAR. 8/ 



not Stop to describe it, but merely mention some of its 

 habits. The eggs are laid upon the trunk, from close to 

 the ground to a height, perhaps, of two or three feet, 

 and, especially in old trees, in the forks of large 

 branches. The eggs hatch and the larvae or worms feed 

 upon the inner bark and sap-wood, eating a space of the 

 size of a silver dollar. As many as ten or twelve have 

 been found in a single tree, and this cause alone is sufifi- 

 cient to account, in a great measure, for the thoroughly 

 exhausted condition of many trees. In order to better 

 understand the nature of this disease and its effects upon 

 the tree, let us glance at some of the functions of the 

 tissue of the plant. In all plants the principal part of 

 the plant-food is prepared or transformed, so as to be in 

 condition to nourish the new growing cells, in the leaf. 

 During the day-time, and under the influence of light, 

 the plant-food taken in from the atmosphere and the 

 soil is being rapidly transformed into starch in the 

 green part of the leaf At night, when the plant is in 

 active growth, this starch is changed into sugar, and it 

 is in this form that it is taken up to nourish the growing 

 tissue. 



Now it is found in diseased trees that there is a 

 large quantity of starch undissolved in the tissues, and 

 that the latter seems to have lost the power of trans- 

 forming it into the proper condition for its nourishment, 

 just as the sick man, although he is able to take large 



