NEEDLES IN SPURS OF PINUS LONGIFOLIA. 117 



The co-relation of the presence of the long shoots to the number 

 of abnormal dwarf shoots is shown below : — 



Plants with long shoots (branched) ... ... 90 



Plants without long shoots (unbranched)... ... 10 



Plants with normal shoots only ... ... 5 1 



Plants with abnormal shoots also ... ... 5 ) 



It will be seen from this that 50 % unbranched plants show the 

 presence of abnormal shoots in addition to the normal shoots, while 

 52 out of 90, i.e., nearly 58 %, of branched plants possess the same 

 peculiarity. This small difference has probably no significance. A 

 very interesting point, however, is that that all the abnormal shoots 

 on these 5 plants were 4-leaved. The details are as follows : — 



Two plants possessed only one such shoot each ; one possessed 

 5 such shoots ; one possessed 8 such shoots, and one possessed 13 

 such shoots. This last plant was growing in a larger pot than the 

 others, 



This relation between the absence of long shoots and the presence 

 of 4-leaved abnormal dwarf shoots only (of course in addition to nor- 

 mal shoots) can hardly be accidental. Of course some branched 

 plants also had 4-leaved shoots, either alone or along with other 

 abnormal shoots, but no unbranched plants were found with any 

 but 4-leaved abnormal shoots. The large size of the pot in one case 

 may explain the large number of the 4-leaved shoots in that plant, 

 but hardly the fact that all shoots were 4-leaved and not even one 5- 

 leaved. Another fact which was noticed in this connection was that 

 plants with few and small branches showed a greater tendency on the 

 whole to form abnormal shoots than plants with long and many 

 shoots but no exact numbers were obtained. 



Below is given an analysis of the plants which possessed five or 

 more abnormal shoots. The total number of such plants was 12. 

 Nine plants had purely 4-leaved shoots as follows : — 



4 with 5 such shoots. 



1 with 7 such shoots. 



2 with 8 such shoots. 

 1 with 10 such shoots. 

 1 with 13 such shoots. 



A combination of 2-and 4-leaved shoots with more than five 

 shoots occurred in one plant : — 2-leaved shoots, 2 ; 4-leaved shoots, 5. 



A combination of 4-and 5-leaved shoots with more than five 

 shoots occurred in one plant : — 4-leaved shoots, 8 ; 5-leaved shoots, 3. 



A combination of 2-, 4-and 5-leaved shoots with more than five 

 shoots occurred in one plant : — 2-leaved shoots, 1 ; 4-leaved shoots, 

 7 ; 5-leaved shoots, 1. 



