248 Vniversity of California Puhlications in Botany [Vol.5 



SUMMARY 



The sum total of the evidence at hand concerning the germination 

 of hybrid vs. parental seed leaves no doubt that different plants 

 of F^, Fo, and F. produce seed the germination of which is signifi- 

 cantly differentiated as to the total amount of the seed that will ger- 

 minate, or as to the length of time during which germination takes 

 place, or as to the period, during the extent of the test, within which 

 the maximum amount of germination occurs. Further, there is evi- 

 dence that among the seeds of a single F, or Fg plant a portion have 

 a characteristic period during which they germinate, which is distinct 

 from the period characteristic of another group of the same seed. 

 The suggestion is made in this connection that if the plants grown 

 from the seeds which germinated most heavily at one period were 

 kept distinct from those resulting from seed with a different maxi- 

 mum of germination the plants within each group would correspond 

 one to another in their inheritance of certain characters. Certainly 

 the results indicate that care must be taken in pricking out seedlings 

 from the seed pans not to discriminate in favor of the larger seedlings 

 if the resulting plants are to exhibit a representative progeny of the 

 parent individual (cf. Goodspeed, 1912, p. 111). Unfortunately our 

 facilities are such that the germination, under controlled conditions, 

 of large quantities of seed is not possible, nor is sufficient space avail- 

 able for growing the number of plants necessary to give final evidence 

 on this subject. Finally, the F^ seed from reciprocal crosses has been 

 shown to differ with reference to its germination. In this connection, 

 either the amount of total germinaion, or the extent of the germinating 

 period, or the days of maximum germination peculiar to one parent 

 have been shown also to be characteristic of the cross-pollinated seed 

 which it bore. 



Transmitted April 8, 1915. 



LITERATURE CITED 



Goodspeed, T. H. 



1912. Quantitative studies of inheritance in Nicotiana hybrids. Univ. Calif. 



Publ. Bot., vol. 5, no. 2. 



1913. Notes on the germination of Tobacco seed. Ihid., vol. 5, no. 5. 

 Setchell, W. a. 



1912. Studies in Nicotiana, I. Ihid., vol. 5, no. 1. 



