290 Canadian Record of Science. 



but such variation is always definitely associated with a vegetat- 

 ive or with a reproductive condition of the branches. In the 

 particular shrub selected for observation, there was a some- 

 what marked luxuriance of growth in the branches of the 

 season (Fig. 6a), these being upwards of 1.27 metres long, with 

 a diameter of 1 cm. at the base. Upon such shoots the leaves 

 were altogether normal as to form and size, with here and 

 there an atrophied member of the base of a branchlet (Fig. 

 fa : 3). Leaves of normal form are strongly cuneate, and 

 show a conspicuously decurrent blade. As shown in the 

 series (Fig. -ja : 1, 2, 4) the leaves increase in size upwards, 

 but again diminish toward the apex of the shoot, to which 

 position leaf No. 4 belongs. Excluding such abnormal forms 

 as No. 3, such leaves show a variation between 2.78 sq. cm. 

 and 9.65 sq. cm., with an approximate average area of 5.64 sq. 

 cm. 



The reproductive shoots produce terminal clusters of 

 flowers which are developed with great luxuriance. This 

 appears to influence a limited development of the branches 

 themselves, which are always small and wiry, usually about 10 

 cm. in length with a diameter of 1 mm. at the base. Among 

 these, and arising from the same main axis, are a few vege- 

 tative shoots also influenced in a marked degree by the 

 reproductive period, but conspicuous by reason of their 

 somewhat more vigorous development (Fig. 6b). They range 

 upwards of 15 cm. in length with a diameter of 2 mm. at the 

 base. On such vegetative shoots, which generally develop from 

 near the extremity of the main axis and appear after the period 

 of inflorescence is well advanced or completed, the leaves 

 approximate very closely in form to those of the ordinary 

 vegetative shoot. They are, however, much smaller (Fig. ja : 

 2, 5, 6). They range in size from 1-34 sq. cm., to 3.11 sq. 

 cm., with an average area of about 2.08 sq. cm. They 

 therefore bear to the leaves of the ordinary vegetative shoot, 

 the relation of 1 : 2.70. On the other hand, the leaves borne 

 upon the short, wiry flowering branchlets, are usually much 

 reduced in size and altered in form (Fig. jb : 1-3). They 

 vary from 0.290 sq. cm., to 1.995 S( F cm - w ' tn an average area 



