20 NEBRASKA STATE HORTICULTURAL SOCIETY. 



and correspond to the ribs and "veins" of ordinary leaves. In a 

 cross section of the apple they show as little dots or points (Fig. 4, B, 

 W B). 



C 



FIG. 4. A, longitudinal, B, cross section of an apple; C, 

 the calyx-tips (or "calyx ") in the "basin"; S, the stalk, 

 in the "cavity"; S P, the five seed-pods, or "core"; W B, 

 the woody bundles of the calyx-tube. 



Normally there should be two seeds in each seed-pod, thus mak- 

 ing ten seeds for the whole core ; but very commonly only one devel- 

 ops in each pod, and sometimes both are aborted. On the other 

 hand, in some varieties, more than two seeds form in each pod. In a 

 general way we may say that it is better for the fruit to have few seeds 

 than many, as it requires much food to perfect seeds, which otherwise 

 might be utilized in the fruit itself. 



THE TREE DISEASED. 



The apple tree, in common with all other living things, is subject to 

 various diseases. Without attempting to enumerate all the diseases 

 to which it is subject in different parts of the world, the following 

 summary statement it is hoped will be helpful to a better understand- 

 ing of its pathology : * 



There are four general causes of pathological conditions in plants, 

 all of which are factors in the pathology of the apple tree. 



I. UNFAVORABLE HABITAT. This includes not only such matters 

 as height above the level of the sea, forest or plain conditions, etc., 

 which may have much more influence than we suppose, but, also, the 



*For a fuller discussion of the subject of plant diseases see the article "Patho- 

 logy" (Vegetable), in the new edition of Johnson's Cyclopedia, vol. VI, from 

 which much of what is here given is derived. 



