290 The Pedigree Fain Hies. 



tions with especial reference to the characters of the 

 young plants. 



I shall describe these characters in greater detail in 

 the following chapter, but it seems desirable to preface 

 it by a short comparative resume. 



I began by sowing the seed in the garden. The 

 result of that was, as I have already mentioned, that part 

 of the seed remained in the ground and germinated in 

 subsequent years. So that each particular part of the 

 garden could only be used once. I therefore adopted 

 the plan of sowing the seed in pans ; the soil for them was 

 bought from a nursery and was sterilized so that any 

 seeds of Oenothera that happened to be in it were des- 

 troyed — a fact completely proved by numerous control 

 experiments. The seedlings remained in these pans when 

 ever possible, until they were old enough to be identified, 

 and until the different kinds had been recorded ; if this 

 was not possible they were transplanted into wooden 

 boxes measuring 30 by 50 centimeters and 10 centimeters 

 deep. They remained in these until they could be planted 

 out in the beds. 



The plants were only grown in pots when it was 

 desirable that they should be treated particularly care- 

 fully or when especially robust plants were wanted. 



A sharp distinction is to be drawn between crops 

 which are intended to flower and such as are recorded 

 and thrown away before the plants develop stems. The 

 former are almost always transplanted from the pans 

 before the characters of the new species are recognizable ; 

 the latter are very often kept in the pans until they are 

 done with. 



Some forms are recognizable as soon as the hrst 

 leaves are developed. This is almost always true of 0. 



