26 TOMATO CULTURE 



in cold, damp weather the flowers often fail of fer- 

 tilization, in which case they drop, and this is often 

 the first indication of a failing of the crop on large, 

 strong vines. I have known of many cases where the 

 yield of fruit from large and seemingly very healthy 

 vines was very light because continual rains prevented 

 the poUenization of the flowers. Such failures, how- 

 ever, do not always come from a want of pollen but 

 may result from an over or irregular supply of water 

 either at the root or in the air, imperfectly balanced 

 food supply, a sapping of the vitality of the plants 

 when young, or from other causes. Insects rarely 

 visit tomato flowers and are seldom the means of their 

 fertilization. 



Characteristics of the fruit. — The fruit of the orig- 

 inal species from which our cultivated tomatoes have 

 developed was doubtless a comparatively small two to 

 many-celled berry, with comparatively dry central 

 placenta and thin walls. In some species the cells were 

 indicated by distinct sutures, forming a rough or cor- 

 rugated fruit. It has improved under cultivation by 

 increase in size, the material thickening of the cell 

 walls, the development of greater juiciness and richer 

 flavor and a decrease in the size and dryness of the 

 placenta, as well as the breaking up of the cells by 

 fleshy partitions resulting in the disappearance of the 

 deep sutures and an improvement in the smoothness 

 and beauty of the fruit. (Fig. ii.) 



The quality of the fruit is largely dependent upon 

 varietal dififerences, to be spoken of later, but it is 

 also influenced by conditions of growth — such as the 

 proportion of the nutritive elements found in the soil, 



