April, 1915.] The Inheritance of Size in Tomatoes. 



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FLUCTUATING VARIATIONS. 



Any quantitative character is subject to deviation from the 

 average condition. According to the laws of chance these devia- 

 tions are sometimes plus and sonietimes they are minus, as a 

 result of which they have been termed "fluctuating variations". 

 Quetelet has shown that all living structures vary and are always 

 grouped about a mean. In other words plus or minus deviations 

 of increasing magnitude occur with diminishing frequency in such 

 a way that a given population will be distributed, in a large part, 

 at or near this mean or mode. Galton called attention to this 



Figure 1 



same fact in another way when he stated that the offspring of 

 parents with plus or minus variations are closer to the average 

 than the parents. There are always certain limits of fluctuating 

 variability beyond which the deviations do not extend. 



Since the fruit of the individual plants were found to be subject 

 to these fluctuating variations in size, it was considered necessary 

 to harvest a large number of fruits from two typical plants in 



