2 Harri.-. A quantitative studj o£ the Factors influencing etc. 



The aiialytical methods employed are those of the modern 

 higher statistics, which are steadily gaining grouml a.s tools of 

 research. Xo other technique known tu ine is capable ofattacking 

 the kind of problem with which \ve have to deaL 



The present section dcals solcly with tbc interrclationships 

 between the eharacters of the pod and the weight of the seed. 

 lt Touches on no factors cxcopr thoso i »eculiarto the fruits in which 

 the seeds are borne — the pods drawn from a „general popnlation" 

 produced by the cultivation ander ordinary garden or field con- 

 ditions of a reasonably homogeneous variety. Thus the niaterial 

 has no experimental artificiality. We are. in fact, studying the 

 physiology of seed development as it normally goes forward. Fac- 

 tors which for the present are left entirely out of account will be 

 taken up in detail later. 



II. Presentation and analysis of data. 



The portion of the data discussed here consists of five series 

 derived from several hundreds of plants, and comprising altogether 

 23.312 individually weighed seeds. These will be referred to 

 hereafter by key letters. They are: 



L. Golden Wax. Grown at Lawrence, Kansas, 1906. 2861 seeds. 



LL. Golden Wax. Plants the offspring of the L. series. Grown 

 at Lawrence, Kansas, 1907. 3947 seeds. 



GG. Burpee's Strindess. Grown at the Missouri Botanical 

 Garden, 1907. 8364 seeds. 



NH. Navy. Grown near Sharpsburg, Ohio, 1907. 5778 seeds. 



XI). Navy. Another series, grown, ander very different con- 

 ditions, near Sharpsburg, Ohio, 1907. 2362 seeds. 



The characteristics of these varieties and the cultural con- 

 ditions under which they were grown have been or will be de- 

 scribed for other purposes elsewhere. The most exact description 

 of the pods and of the seeds is furnished by the physical constants 

 derivable from the tables of data. 



The Influence of Number of Ovules and of Number of Seeds per Pod. 



The data may be best shown in a series of Condensed tables, 

 in Table I. Here, the first column shows the number of ovules 

 formed (the denomiuator) and the number of seeds developing (the 

 numerator ) in the pods considered. The number of seeds weighed 

 and the total weight (in working units of .025 grams) of seeds 

 produced for each class of pods is given in the 5 pairs of columns. 1 ) 



J ) Frorn the data in this table, the physical constants (means, Standard 

 deviations and coefficients of Variation) for ovules per pod. seeds per pod. 

 ovules failing to develop per pod, and seed/ovule index can be calculated, as 

 well as the rough moments for the correlations between these eharacters and 

 seed weight. The correlations are completed by a knowledge of the Variation 

 constants for seed weight by a ruethod explained elsewhere (Amer. Nat. Vol. 44. 

 1910. p. 693-699.) 



