386 COOK 



continued to be accepted as a sufficient cause of the extensive 

 modifications which have taken place. 



The question has been debated at length on theoretical 

 grounds, but without decisive results, since it appeared to lie 

 outside the range of experimental determination, owing to the 

 vast periods of time which have figured in the calculation. 

 Fortunately, all plant cultures are not the same in method or in 

 history, and the so-called Arabian coffee furnishes an instructive 

 contrast with other domesticated species. Coffee has prob- 

 ably not been in cultivation much more than a thousand years, 

 and has existed but a few centuries, or often only a few decades, 

 in its present centers of production. It is not an annual, but a 

 shrub, or small tree, the selective improvement of which would 

 require more years than planters generally expect to give to the 

 business. Plantations are generally large, and experiments 

 with individual trees are difficult and time-consuming, so that it 

 is only within recent years that the securing of improved varie- 

 ties of coffee has received serious attention. The evolutionary 

 factors of selection and of long periods of local influences of 

 soils and climates are thus alike absent, and yet there is no lack 

 of coffee varieties with abundant diversity in form, habit and 

 color. Their general similarity consists only in being inferior 

 in fertility to the parent type. 



So much has been written upon the improvement of plants by 

 domestication and selection that this inferiority of coffee varie- 

 ties may seem exceptional, but the apparent anomaly disappears 

 if we reflect that fruit trees and other horticultural plants sup- 

 posed to have been greatly improved in domestication are not 

 grown for the seeds, and hence complete fertility in the sexually 

 reproductive sense has been a minor consideration or even a 

 positive disadvantage ; indeed, with many plants it has been 

 one of the direct objects of selection to reduce the number of 

 seeds or to eliminate them completely. More or less seedless 

 abnormalities are valuable, for example, among the grapes, 

 plums, and oranges. If coffee were cultivated as an edible 

 fruit the new sorts would be of use, since thicker pulp and 

 smaller seeds are frequent characteristics of the berries ; indeed, 

 a coffee which did not produce any normally developed seeds 



