142 



Sex Segregation in the Bryophyta 



scheme an alternative reading is given {A and B). If the purity of the 

 gamete for sex characters be maintained, a sex segregation in the somatic 

 tissues of the gametophyte is assumed to occur (B). This point will be 

 considered a little later. 



Quite naturally the question arises, how far can the facts of sex in- 

 heritance gained from the study of animals, be applied to these plant 

 forms, if indeed they can be applied at all ? At the outset it must be 

 borne in mind that in general, meiosis accompanies gametogenesis in 

 animals, and sporogenesis in plants. Exceptions occur in plants, as for 

 example in the Fuci, where there is no alternation of generations and 

 reduction occurs at gametogenesis. 



Assuming that in a monoicous (^) form of moss, the gametophyte 

 produced J^ gametes bearing the male factor, and $ gametes bearing 



SCHEME I. 



Sporophyie 



Apcsporoas Itiie. 



<r 



( ( ( 



@ 



1579. /S4. 5 

 Oierile axes. 



0., g)< Spores 



( 



) 



Leafi^ 



> Gajrteiropkyte. 



(ny (J)^ Gameles j 



__3poropAyi€ 



Dioicous ij/pe. 



