136 COCOA CHAP. 



the same height above the soil as they were in the 

 nursery. 



Layering (marcotting}, grafting and budding. 

 Grafting, budding and layering (marcotting) experi- 

 ments have been conducted in several countries, especially 

 at Experiment Stations. None of these methods has so 

 far been put into general plantation practice, and there 

 is no definite information as to how plants propagated 

 in such manners will be able to resist disease, what yield 

 may be expected, what age they will attain, etc. As 

 long as our knowledge is at this stage, budding, grafting 

 and marcotting of cocoa may be an object of study and 

 experiment in Botanic Gardens and Agricultural De- 

 partments, but the time has not yet come to recommend 

 the planter to apply any of these methods of vegetative 

 propagation on a large scale. 



There are, however, probably some planters who would 

 like to try these methods and to form their own opinion 

 as to their advantages and disadvantages. For this 

 reason the different methods will be briefly described. 



First of all, what is the use of marcotting and 

 grafting, or, in a general term, " vegetative propaga- 

 tion " ? The aim is simply to obtain an offspring which 

 is wholly like the mother tree. 



There is a large group of plants in which the offspring 

 is generally different from the mother plant. This is 

 the group of hybrids. When, for instance, a Liberia 

 coffee tree is pollinated by an Arabica coffee tree, the 

 offspring are hybrids, which have characters both from 

 the Liberia mother and from the Arabica father ; they 

 are uniform among each other, and more or less inter- 

 mediate between the two parents. When, however, 

 we sow out the seeds of these hybrids, we obtain an 

 offspring which is not at all uniform ; it contains very 

 different plants, some more like the Liberia grand- 

 mother, others more like the Arabica grandfather ; but 

 almost every tree is different, and each contains Liberia 

 and Arabica characters in a new combination. 1 



1 Some hybrids are "constant," and remain the same in their progeny. 



