38 



HEREDITY AS ILLUSTRATED BY TRICHOMES. 



JfiO.g.ftlehomefotJugtanteaHfornlea : nir/m, Fj: a, awn-shaped trichome from a leaf; 6 to d, 

 dlsk-stiaped trichomes ; e to i, some stages in the development of long secreting trichomes : 

 .;', transverse section of head of mature long secreting trichome ; k to HI, long secreting tri- 

 chomes ; n to r, long secreting trichomes of the type having a head of more than 4 cells: 

 n, longitudinal sections of the head of a single trichome; o to </, views of long secreting tri- 

 chomes ; r, transverse sections of head of long secreting trichomes of different ages ; ., some 

 stages in;the development of short secreting trichomes. (All figures 535; reduced one- 

 fourth.) 



