PLANT HYBRIDIZATION BEFORE MENDEL 265 



In Erica watsorii, a natural hybrid between E. ciliaris and 

 E. tetralix, the hybrid was found to be very evenly balanced. 

 Details are given of the anthers only. (p. 544.) In a cross between 

 Rhododendron ciliatum and R. edgeworthii, the hybrid is said 

 greatly to resemble the former parent, and scarcely at all the 

 latter in its gross morphology. In the histological details of leaf 

 structure, however, "the minute features of both parents were, 

 strongly traceable in the hybrid." (p. 544.) 



In a cross between Cyprvpedium insigne and C. villosum, the 

 number of the stomata was found to be as follows, for the mag- 

 nification used : 



In a cross between Cypripedium harhatum and C. insigne^ the 



relationship was as follows, in respect to the distribution of the 



stomata : 



C. barbatum 3-4 



C. insigne 11 -12 



C. ashburtonae (hybrid) 6-7 (p, 544.) 



In a rather brief contribution to the Gardeners' Chronicle for 

 June 20, 1891 (6c), the matter of color, flowering period, and 

 constitutional vigor of hybrids is discussed. The article in ques- 

 tion seems to have been contributed in view of Henslow's paper 

 before the Royal Horticultural Society, May 12, 1891, and re- 

 viewed in the Gardeners' Chronicle for May 16, on color inheri- 

 tance in "greenhouse Rhododendrons." Macfarlane holds that the 

 evidence from Henslow's examination, to the effect that color- 

 inheritance was more or less a variable matter, should probably 

 be modified. His statement is interesting, in that it shows an ap- 

 proach of mind toward a stricter scientific use of the materials in 

 crossing. He remarks : 



* 



"l feel that it will eventually be possible, in the great majority of 

 cases, to predict the exact color which the hybrid will show, especially 

 if the color in each parent be due to the presence of one' pigment only" 

 (6c) ; the examples chosen by Henslow being complicated by the frequent 

 presence of two pigments, a dissolved red and a granular yellow, in at 

 least one of the parents. 



"if we compare parents which each develop one pigment, or one of 

 which only is white, i.e., devoid of colour, it may be laid down as a 

 broad general rule, that the hybrid will be intermediate between the 

 two, having regard to the size of the floral parts of each." 



