96 PLANT HYBRIDIZATION BEFORE MENDEL 



the constitutional than the closer botanical affinities of the parents." 

 (2C, p. 342.) 



As to whether there was a real fundamental difference between 

 plants which could produce fertile and those which could produce 

 only sterile offspring by crossing, Herbert says further: 



"it was my opinion that fertility depended much upon circumstances of 

 climate, soil and situation, and that there did not exist any decided line 

 of absolute sterility in hybrid vegetables, though from reasons which I 

 did not pretend to be able to develop, but undoubtedly depending upon 

 certain affinities either of structure or constitution, there was a greater 

 disposition to fertility in some than in others. Subsequent experiments 

 have confirmed this view to such a degree as to make it almost certain — 

 that the fertility of the hybrid or mixed offspring depends more upon 

 the constitutional than the closer botanical affinities of the parents." 

 (2c, p. 342.) 



He holds that it obtains as a general fact throughout the plant 

 kingdom, that species which have close botanical affinity, if they 

 have widely different soil or climatic requirements, are apt to pro- 

 duce sterile offspring as the result of a cross, while, if they have 

 the same constitutional habit, they tend to give rise to fertile 

 offspring. 



From the standpoint, then, of a practical plant hybridizer and 

 horticulturist, Herbert holds that : 



"Any discrimination between species and permanent varieties of plants 

 is artificial, capricious, and insignificant ; that the question which is 

 perpetually agitated, whether such a wild plant is a new species, or a 

 variety of a known species, is waste of intellect on a point which is 

 capable of no precise definition." (2c, p. 346.) 



"The effect, therefore, of the system of crossing, as pursued by the 

 cultivator, instead of confusing the labors of the botanist, will be to 

 force him to study the truth, and take care that his arrangement and 

 subdivisions are conformable to the secret laws of nature ; and will only 

 confound him when his views shall appear to have been superficial and 

 inaccurate ; while on the other hand it will furnish him an irrefragable 

 confirmation when they are based upon reality." (2C, p. 346.) 



The attitude of Herbert with regard to the production of hy- 

 brids was not, however, so much the attitude of the scientist as 

 that of the horticulturist and florist. His point of view is well 

 stated in the following: 



"To the cultivators of ornamental plants, the facility of raising hybrid 

 varieties affords an endless source of interest and amusement. He sees in 

 the several species of each genus that he possesses, the materials with 

 which he must work, and he considers in what manner he can blend them 

 to the best advantage, looking to the several gifts in which each excels, 

 whether of hardiness to endure our seasons, or brilliancy in its colors, 



