Practice of Plant Breeding 



another, set (seed from 5200 feet) were only 30 inches 

 high and grew 2.4 inches in the same year. 



At Adlisberg also larch-seedlings (seed from Avers 

 6300 feet, and Engadine 6900 feet) were only 9 and 15 

 inches high respectively. These young trees stopped 

 growing on June 27th and July 2nd. 



As a control experiment, larches of the same age 

 from Bonaduz seed (2350 feet) were 26 inches high, 

 and went on growing till August i8th. 



Sycamores (three-year-old) from Alp Drusen seed 

 lost all their leaves on October i3th and were not 

 more than 16 inches, whereas others from Adlisberg 

 seed were 25 inches in height and remained in leaf until 

 November i2th. 



Such instances as these quite conclusively prove the 

 inheritance of such habits as slow growth, time of 

 growing, and of leaf-fall. Those parent larches which 

 grew at 6000 feet and over had surely acquired the 

 habit of slow growth simply because there was too 

 short a season to grow fast. And as we have seen, this 

 habit was transmitted, somehow, to their seedlings. 



The parent sycamores on Alp Drusen would certainly 

 have had their leaves killed off by frost, &c., in the middle 

 of October, and had transmitted the habit of shedding 

 their leaves at that date to their descendants, who had 

 never known a severe Alpine climate. Perhaps even 

 more interesting are those experiments of Klebs, who 

 was able by varying the conditions of growth to change 

 the colour of Campanula trachelium from blue to white, 

 and again by another change from white to blue. 14 



Both blue and white varieties not only of Campanulas 

 but of all sorts of flowers regularly inherit the colour of 

 their parents when cultivated under the same conditions. 



So that this third method, that of varying the condi- 

 tions of cultivation, is quite as promising as either selec- 



292 



