SOLANACE/E 5^9 



Extensive experiments made by Fletcher and Gregg with 

 f^reenhoiise or forced tomatoes showed that self-fertiUzed 

 blossoms set fruit as well as cross-fertilized ones. Further- 

 more, there was practically no difference in the appearance 

 or weight of the fruit, and no difference in the number of cells. 



Parthenocarpy.— This phenomenon is not at all uncommon 

 in tomatoes. By this is meant the ripening of the fruit 

 without the fertilization of the ovules. Such fruits, of 

 course, possess no gcrminative seeds. 



Abnormal Tomatoes. — Munson has found, in crossing 

 tomatoes, that the amount of pollen placed on the stigmas 

 affects the size of the fruit. Two stigmas in the same flower 

 chister were given different amounts of pollen: one abun- 

 dant i)olIen, the other lo to 20 grains. With plenty of 

 pollen, normal fruit resulted, while with scanty pollen, small 

 and fleformed fruit resulted. In the first case, there was 

 abundant seed, while in the latter, only a few seeds. One- 

 sided tomatoes result when pollen falls upon one side of the 

 stigma only. It is undoubtedly commonly true that small 

 and irregular tomatoes are caused by an insufficient sui)ply 

 of pt)llen. 



The Mature Fruit— The fruit is a true berry (Fig. 240). 

 The wild form of our common garden tomato US', csniloiluni) 

 has a two-celled fruit with a rather (lr\- placenta. 'i"he cells 

 are delinite in both number and shape. C'ultixaled tornis 

 of the common garden tomato have a number ol cells in the 

 fruit; thev are indehnite in both nuinl)er and shape, and the 

 placenta is exceedingly lleshy. The fewest celled fruits are 

 eonsi.lered nean-st the original tyi)e. The pear and cherry 

 tomatoes l)oth have two-celled fruit, 'i'he calyx is persist- 

 ent, adhering to the base of the fruit. The fruit \aries in 

 shape, color, and smoothness of surface. The seeds are 

 numerous and small. 



