274 



PLANT HYBRIDIZATION BEFORE MENDEL 



Sto7nata {lower 361" long x 24M 26x25/* 

 surface) wide 



32/* diam. 



Chloroplasts 

 of guard cells 



20-22, and meas- 

 ure 2/* diam. 



12-14, and meas- 15-17, and meas- 

 ure 1.8/A diam. ure 2.5/^ diam. 



Tentacles 



Pigment confined Pigment richest Pigment less 



to the oval or 

 elliptical head 

 of each tentacle, 

 Hair-stalk green 



in the head-cells, 

 but distributed 

 in the cells of 

 each stalk for 

 2/3 its length 



pronounced, and 

 extends 1/3 to 

 nearly 1/2 the 

 length of the 

 stalk 



Cortex 



4-5 rows of thin- 1-2 layers of 2-3 layers of 



walled parenchy- parenchyma. 3-4 parenchyma cells. 



ma cells, with 

 abundant chloro- 

 plasts. 5-6 layers 

 of sclerenchyma 

 tissue 



layers of slightly 4-5 layers of 

 sclerench^'ma sclerenchyma 



tissue tissue 



Macfarlane deserves to be remembered, therefore, among those 

 who have contributed to build up a substantial knowledge of the 

 hybridization process, because of the exact character of his in- 

 vestigations, and his anticipation of the discoveries made only 

 after the publication of Mendel's papers. His contribution, funda- 

 mentally speaking, may be summed up in his own words as 

 follows : 



"From extended observations that the writer has made, alike on living 

 plants, and on their minute tissues, he adheres to the view that an aver- 

 age hybrid is nearly intermediate between the parents." (6f .) And that : 



"Every cell of a plant inherits the peculiarities of both parents, at 

 times in a perfectly balanced way, so far as our limited powers of study 

 can carry us, at times with an evident leaning or bias to one parent." (6a.) 



