REPRODUCTION BY LAYERING IN THE BLACK SPRUCE 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 173 
GEORGE D. FULLER 
(WITH SIX FIGURES) 
During the summer of 1912, while making some ecological 
studies along the Saguenay River, Quebec, attention was directed 
™ 
Fic. 1.—The black spruce growing on granite with a basal whorl of prostrate 
branches; ‘Celina’ County, Quebec. 
to the process of forest development upon granitic areas with very 
little soil, where the rocky surface was exposed to the full sweep 
of the wind. The most careful studies were made on a series of 
Botanical Gazette, vol. 55] [452 
