5o THE PLANT WORLD 



separate rows of each culture, always beginning with (I) at 

 the label-stake and always counting in the same direction 

 across the garden. Letters of the alphabet always refer to 

 types or classes of plants distinguished by morphological 

 differences sufficiently described in the pedigree-records, and, 

 when practicable, also represented by specimens in the her- 

 barium. 



It is so generally necessary to make notes regarding in- 

 dividuals before it can be known whether they will ever be 

 used as progenitors, that it is necessary to assign some tem- 

 porary designation which may afterwards be replaced by a 

 permanent number when it is decided to use them. For this 

 temporary label I use the Arabic numeral in curves, thus ( i ) , 

 (2), etc. All notes entered in the note book regarding any 

 particular individual refers to it under the number thus as- 

 signed. This refers only to pot cultures in which each plant 

 has its own label bearing the pedigree-number of its mother. 

 Tn the garden, the individual plant is not given a separate 

 label, but is referred to in terms of its location. Thus "III. 

 13" indicates the thirteenth plant in the third row, counting 

 the row bearing the label-stake as the first. 



In the construction of the permanent pedigree-numbers, 

 there are several things to be kept in mind : The tracing of 

 pedigrees through successive generations must be facilitated; 

 connection of each member of the pedigree with the notes 

 regarding its characters, and those of its family must be made 

 as perfect and simple as possible; and numbers must be kept 

 from getting too large, as the likelihood of incorrect writing 

 and reading of large numbers is very much greater than 

 small numbers. To attain these ends I begin all pedigree 

 numbers with the last two digits of the year in which the 

 mother of the corresponding culture was grown, and follow 

 this by the number of the page in my notebook for that year, 

 on which the current notes are entered regarding the offspring 

 of this particular plant. Thus 06230 indicates a plant, the 

 complete history of whose offspring during one generation is 



