456 



Thk Journai, of Hkkkditv 



of height is to determine the exaet 

 point at which the plants should be 

 divided on the one hand into Tails and 

 on the other hand into Dwarfs. 



After some consideration it was 

 decided to take the mid-point of the 

 measurements as the dividing line 

 between Tails and Dwarfs; for example, 

 any plants exactly half-way between 

 the tallest plant and zero should be 

 classed as Dwarf, while those having a 

 greater height measurement than the mid- 



point should be placed in the Tall class. 



When the plants were measured their 

 a\'crage heights were found to vary 

 from two inches up to eleven inches. 

 Then taking the mid-point at 5.5 inches 

 all plants which measured up to this 

 height inclusive were placed in the 

 Dwarf class; those above 5.5 inches 

 being placed in the Tall class. 



On analyzing the measurements it 

 was found that the plants arranged 

 themselves in the following manner: 



Segregation of plaats according to height. 



If we accept the arbitrary standard A close inspection of the plants 

 of measurement used for grou])ing the showed that as with height the variation 

 Tails and Dwarfs, it will be seen that in in habit of gro\\1:h was continuous, 

 view of the small niunber of plants Beginning with the prostrate form as 

 studied the actual segregation is fairly characteristic of black medick there 

 close to theoretical expectancy, the Tall was found to be a continuous series 

 character being dominant and the ranging through decimibent and semi- 

 Dwarf character recessive, erect up to the erect fonn; this latter 



habit resembling the female parental 



n.vBiT OF GROWTH. form (alfalfa). 



In order to resolve a continuovis series 



A reliable determination as to whether of this kind into two grou]js the method 



there is any segregation in habit of was adojjtcd of first classifying the 



grrnvth is even more difficult to obtain plants into four subdivisions, then 



than in the case of height; and as no arranging the subdi\nsions into two 



simple measurements can be made to be main groups by which means the plants 



of use, any determinations for ]Durposes fall naturally into one of two grou])s one 



of classification must be made by of which has been termed non-erect and 



observation. the other erect, as shown in table below: 



Segregation of habit of growth 



Prostrate forms 3 plants] 



[ non-erect 88. 



Decumbent 85 plants] 



Semi-erect \>\ )lants1 



1- erect 20. 



Erect 8 plants] 



