PLANT HYBRIDIZATION BEFORE MENDEL 



269 



The structural details of cells from Cytisus adami and its 

 stock-graft parents are as follows : 



CYTISUS LABURNUM CYTISUS ADAMI (gRAFT- 



(stock) hybrid) 



Cortex 

 13-15 layers 13-15 layers 



sclerenchyma cells, sclerenchyma cells, none 5 longitudinal masses 

 none 



Leaf 

 epidermis covered with epidermis, glabrous 

 spindle-shaped hairs 



Vascular bundle of petiole 

 Phloem (sieve-tubes) 

 6 4-4.5 



Xylem (tracheids) 

 20 14-15 



Epiderm.is 

 (stomata in field) 

 (X400) 

 (upper) 12-14 (upper) 



40 (lower) 17-20 (lower) 



Flower, 

 Petals. 



Standard. 

 glabrous marginal fringe of 60-65 



hairs 

 wings 

 glabrous marginal fringe of (av.) 



90 hairs 

 Keel 

 glabrous marginal fringe of 



48-50 hairs 

 Stamens 

 Pollen-cells (diam.) 

 2 1 -23 M 23-25 i" 25-26 At 



cytisus purpureus 

 (scion) 



7-10 thin-walled layers 

 5 longitudinal masses 

 of sclerenchyma cells 



epidermis, glabrous 



3-4 

 8 



27-30 (upper) 

 30 (lower) 



marginal fringe of 

 125-130 hairs 



marginal fringe of 

 160-170 hairs 



marginal fringe of 

 100-1 10 hairs 



