82 



The Canadian Field-Naturalist. 



[Vol. XXXV. 



A.), it appears that the German authority 

 refers to a general opinion that the mater- 

 ial contained in the stump prior to felling 

 might be the only source of the new forma- 

 tions, and that they might also be due to 

 root-graft between the stump and a tree 

 possessing its crown; but he instances ab- 

 solutely isolated stumps in which he avers 

 the reserve material would not be suf- 

 ficient 'explanation of the bulky forma- 

 tions which take place. He refers, in this 

 connection, to the chlorophyll to be found 

 in the rims of the overgrowth and says 

 there is no reason why this chlorophyll 

 apparatus .should not assimilate as well as 



the green bark of the trunk. 



It appears then that European views of 

 the cause of the overgrowth have differed. 

 Wliile the overgrowth is conceded on one 

 hand to be a consequence of root-graft 

 there are authorities who think -it might 

 be initiated by reserve material, and in the 

 case of isolated stumps that the chlorophyll 

 in the rims of the overgrowth might fulfil 

 the functions of foliage. No particulars 

 are given, so far as I can learn, of the 

 steps which were taken to establish that 

 the remote stumps were absolutely isolated. 



On this continent Prof. Willis Linn Jep- 

 son appears to be the first to publish any 



Fig. 1: Douglas fir, Pscjdotsuga taxifoMa (Poir.) Britt. Completely capped-over Douglas 

 fir stumps living posts the vitality and capping-over being due to root union 

 with foster-tree to the right, ijocality, Admiral's Eoad, Esquimalt district, 

 Vancouver Island. 



