467 



Internal injuries in juicy fruits, caused by hail, are interesting. Fig. 

 94 shows a cross-section of a tomato fruit skin struck by hail. We notice 

 at the left, the actual place hit, a hard, dry dark-brown excrescence, 

 the blow of the hailstone did not destroy the epidermis (e). The more 

 tender sub-epidermal tissue was fatally bruised and consequently turned 

 brown and dried (t). As a result of the further process of swelling, the 

 tissue of the still unripe fruit is torn and transformed to a hard cyst. 



Besides this injury, which is most strikingly noticeable, however, a 

 second hard place is found in the juicy flesh of the fruit surrounding a 

 vascular bundle ((/). The hardness of the tissue arises here because of 



Fig-. 94. Cross-section throug-li the fruit wall of a tomato strucli by hail. (Orig-.) 



e epidermis of the outside of the fruit, />' epidermis of the inside of the fruit wall. 7i' dead edge of the wound 

 cut oiT from the living tissue by plate cork W, r cells elongated radially and in part forming dividing walls, 

 in normal cells of the fruit flesh. /the beginning of the formation of plate cork, g vascular bundle, /t vas- 

 cular bundle sheath, « division of the cells which are over-elongated radially to form a vascular bundle. 

 k zone of cork tissue, s/ starch, z collapsed cells with swollen cork walls. 



suberization, which has affected the whole spot after the cells had begun to 

 elongate and divide freely in the vicinity of the bundles. This has probably 

 been initiated by the change in a ring-like zone (s) at a definite distance 

 from the vascular bundle due to the blow from the hailstone or its after 

 effect. Some of the cells have collapsed from the swelling and suberization 

 of the walls ; in other cells, the walls have only swelled, while the walls of 

 the adjacent cells have only been suberized. When the hail fell, the fruit 

 was still green and rich in starch and, during suberization, the starch was 

 retained in the irritated tissue zone, while, during the ripening, it has disap- 

 peared from the rest of the fruit flesh. On this account, we see a ring 

 drawn about the vascular bundle, composed of deep brown tissue filled with 

 starch (st). 



