294 Canadian Record of Science. 



fifth that of leaves on normal, vegetative shoots. Such 

 depauperate leaves do not find a place in the diagnosis of the 

 species, but the latter rests upon a description of the larger 

 forms occurring upon the non-flowering branch — forms which 

 are in general, common to the plant as a whole, and which 

 arise only after the period of inflorescence is well advanced or 

 even completed, as also during a time when there is great 

 activity in the formation of new shoots. The cause of the 

 reduced leaves on flowering shoots is obviously to be referred 

 to relatively defective nutrition, or, to put it in another form, to 

 a diversion of energy and its concentration upon the reproduc- 

 tive process, what Goebel would describe as a survival of 

 juvenile forms, representing airest of development through 

 correlation 1 with reproductive shoots. This is apparent not 

 only through a comparison with vegetative branches, but by 

 reason of the greatly reduced size and ephemeral character of 

 the flowering branches which shortly disappear through a pro- 

 cess of natural pruning ; while it is further substantiated by 

 the fact that as soon as the fruit is formed, and the energy 

 thus employed has been liberated, the same branch gives rise 

 to relatively vigorous branchlets with larger and more normal 

 leaves, and the whole plant enters upon a period of most 

 vigorous growth. In this we have a simple expression of a 

 widely exhibited and well known law. 



In Lonicera the case is somewhat different. There the 

 variation of foliage is of a much more striking character ; it 

 does not arise periodically as in Spiraea but sporadically ; the 

 forms are more extreme and the variation does not depend so 

 much upon conditions of inflorescence, since the reduced 

 forms of the leaf and the normal forms are found about 

 equally associated with the production of flowers. It has 

 been shown that in the case of this plant, essentially three 

 types of foliage have been produced, and that the reduced 

 forms were found exclusively upon each of two individuals 

 which, chiefly through pruning, were much inferior in stature 

 to their neighbors. Here it is not possible to refer the altera- 

 tion of form and size to the well known effects of light and 



I. Organography, 58 and 143. 



