84 PROCEEDINGS OF THE ACADEMY OF [1899. 



CONTRIBUTIONS TO THE LIFE-HISTORY OF PLANTS. No. XIII. 

 BY THOMAS MEEHAN. 



I. Sex in flowers. — Corylus rostrata. 



Since the publication of my first paper on the law governing the 

 sexual characters of flowers/ and others subsequently on the same 

 topic, the evidence of the soundness of the principles therein pre- 

 sented is everywhere so palpable that I have for some years past 

 given up noting it and placing it on record. The principle 

 then and subsequently made plain is, that in the earlier stages of 

 its life a flower bud maybe either male or female, and that the final 

 determination of sex is a mere question of nutrition. If there be 

 an abundant supply of nutrition available, or vital power capable 

 of availing itself of the nutrition provided, the female character- 

 istics prevail. With lessened nutrition, or of vital power in the 

 floral matrix to make use of nutrition, the male characteristics 

 result. These views, opposed as they were by eminent biologists, 

 and even ridiculed by my esteemed friend Prof. Agassiz on the 

 reading of my paper, I have lived to note are generally accepted, 

 though at times it seems to me that a few more recorded observa- 

 tions might be profitable. Before me at this time is an able paper 

 by Prof. Kenjiro Fujii, of the Impel ial University of Tokyo, 

 Japan, on sexuality in the flowers of Pinus densiflora.'^ He 

 finds in his observations that the sex of the flowers is undeter- 

 mined until a certain stage of development, and that a flower which 

 would otherwise develop into a male has a tendency to become 

 female when local increase of nourishment takes place at a certain 

 stage, or during certain stages of its development. This seems so 

 like the language of my papers of a quarter of a century ago, that 

 it is pleasant to know that Prof. Fujii has worked the conclusion 

 out in utter ignorance of my having occupied the field before him. 



^ Proceediugs of Americaa Association for the Advancemeut of Science, 

 1809, p. 2.56. 



^ Tokyo Tlotan'cal INIagozine, Vol. ix, No. 101. 



