86 PROCEEDINGS OF THE ACADEMY OF [1899. 



fail to be impressed with the truth of the principle I have ad- 

 vanced, that the question of sex in flowers is merely a question of 

 nutrition in an early stage. 



For reasons already given, the fact is not so apparent in Corylus 

 Avellana. In the later period of the growing season, in this 

 species, some of the axillary buds develop to short branchlets 

 instead of remaining as buds to bear flowers, and make growth for 

 the coming year. It is from the axillary buds of this secondary 

 growth that the male catkins appear, and thus present the appear- 

 ance, from their elevated position, of being superiorly situated as 

 regards nutrition than the female flower buds, Avhich are only 

 apparently below. When closely examined it will readily be seen 

 on how weak the axes and how very unfavorably for nutrition these 

 buds of the male catkins are situated. 



It may be noted that the axial buds, bearing the male flowers in 

 Corylus rostrata, develop slightly to a branchlet in the fall of the 

 year, but I have never seen one to reach more than a quarter of 

 an inch in length. 



I know of no monoecious plant that does not show a more or less 

 continuous activity during the early autumn, or even during the 

 winter season if a few days of springlike weather occur, and the 

 postulate may be presented that a marked characteristic in the 

 growth of a female flower is the greater conservation of energy dur- 

 ing its early stages, as compared with a tendency to reckless expen- 

 diture in the male floAvers. After all, this is but another Avay of 

 expressing what has already been made plain, that the ability to 

 store and to profit by nutrition accounts for sexual differentiation. 



II. Clethra alxifolia in relation to its morphology. 



In families where there is considerable irregularity in the number 

 and arrangement of related plants, it is important in what might be 

 termed genealogical botany that the primary type should be Avell 

 understood. In Ericacere, for instance, we have genera with vary- 

 ing numbers in the calyx, corolla, gtamens, and styles; some are 

 gamopetalous and some polypetalous, while some have inferior and 

 others superior ovaries. 



As all parts of a plant from the starting in growth of the seed 

 to the final maturity of the flowers it produces are but modified 

 leaf-blades, the arrangement of the leaf-blades on the primary stem 



