SEXUALITY AND THE ENVIEONMENT. 249 



in his ternaries on some Bicecious Plants,^ " 1 think seeds 

 themselves are probably not either male or female, but that 

 after influences produce the sex ; as in animals the sex is not 

 developed in the early embryo life of the creature, nor till 

 the embryo has attained a certain age." 



On the other hand, F. Heyer thought sex was determined 

 at an earlier period than the rijDening of the seed.f Some 

 differences which have been noticed in seedlings of Nutmegs 

 seem to countenance this idea; thus Mr. Prestoe, in his 

 report on the Trinidad garden, ;{: says that " the leaf of the 

 female seedling is most perfectly elliptical, with straighter 

 primary veins. In the male plant it is broader towards the 

 point than at the middle, i.e. obovate, and furnished with a 

 point much longer than that of the female. The veins are 

 also curved in towards the point much more roundly than 

 in the latter." 



An interesting experiment by Mr. T. Anderson-Henry, 

 recorded in the Gardeners Chronicle of 1876, may be quoted. 

 He says, " I raised a seedling Begonia having female flowei'S 

 only. It resulted from an experiment I made on the seed- 

 bearer by cutting off two of the three lobes which compose 

 the stigma, and fertilising the remaining lobe, I repeated 

 this experiment ; and all of the progeny which have yet 

 bloomed, consisting of four or five plants, have likewise all 

 come with female flowers only." This seems to show that 

 the female seedlings were due to concentration of energy to 

 a limited number of seeds. On the other hand, a hybrid 

 Begonia^ " Adonis," raised by Mr. Veitch from a summer- 

 flowering tuberous variety, " John Heal," crossed with a 

 ■winter-flowering variety (itself obtained from B. Socotrina 

 crossed by a dwarf- flowering tuberous variety), bore nothing 



* Journ. ofBot, 1864, p. 232 (note), t Journ. Micr. Soc, 1884, 251. 

 X Gard. Chron., 1884, p. 315. 



