482 The Ohio Naturalist. [Vol. XV, No. 6, 



a circular space of ground about 10 feet in diameter. Unfor- 

 tunately no fruits were weighed while the plant was grown in the 

 greenhouse, but any increase in the size of fruit, as a result of the 

 garden conditions, was so slight as not to be apparent. 



The second experiment was completed in order to detennine 

 the effect of a soil which contained very little plant nutriment 

 that was available, upon the size of plant and fruit. Plant 10 of 

 the F-3 generation (17-12-4) grew in the greenhouse to be about 

 7 feet tall and possessed an average fruit of 2.22 grams. A cut- 

 ting of this plant was grown in an eight-inch pot filled with pure, 

 washed, desert sand which contained very little plant nutriment. 

 An inch layer of nomial pot-soil was added in the middle of the 

 pot as it was feared the scarcity of nutriment would cause the 

 plant to die before it reached maturit3^ The light temperature 

 and moisture conditions were identical with both plant 10 and the 

 cutting. The plant in the sand grew to be only 21 inches high 

 and its average fruit weight was found to be .85 grams. The size 

 of plant and fruit were reduced 75% and 61% respectively. This 

 shows the effect of extreme lack of the essential nutritive sub- 

 stances upon the size of the plant and irmt. 



In addition to the F-1 plant grown in the garden, as described 

 in the first experiment, a number of other plants of the parental 

 and hybrid generations of this currant-pear cross has been grown 

 both outside and inside the greenhouse. Any effect upon the 

 fruit, as a result of greenhouse environment, would probably be 

 shown by a decrease in size. So far as can be ascertained, however, 

 from all the evidence now at hand, there was no apj^reciable 

 difference in the size of fruits as a result of the different environ- 

 mental conditions of the greenhouse and garden. 



Even if there were a small diminution in the size of the tomato 

 fruit as a result of being grown in the greenhouse, this change of 

 size would affect all ]3lants in the same way and in the same pro- 

 portion, and, as all the plants concerned in this jjroblem are 

 greenhouse grown, the accuracy of the ratio between the sizes of 

 the parents and offsprings, which is the vital part of the thesis, 

 would remain unimpaired. 



The average weight of the first ten fruits of a plant was com- 

 pared with the average weight of ten fruits taken in the latter part 

 of the fruit bearing ])eriod. A number of plants were examined 

 in this manner and it was found that the fruits which ri])cned first 

 were not larger than those which ripened later, nor was any cor- 

 relation discovered between the size and time of blooming. The 

 relation between the time of blooming and the size of fruit on a 

 single cluster was examined and considerable data collected but 

 no correlation was found to exist. 



