2:^(5 PHILOSOPHICAL NOTES ON 



Avbieli results i'rum these eoiisidenitions is that the seed-bearing 

 plant, with its jjollen grains and embryo-sacs, is the equivalent of 

 the sjiore-producing generation of heterosporous vascuLir crypto- 

 gams," that is, of those which have both male and female spores. 



Both pollen cells and spore cells germinate in a similar 

 manner. The ones are naked, the others covered. In the ovules 

 of Gymnosperms and Angiosperms, something similar occurs. 

 Those are naked, these are covered. That is, relatively covered by 

 the curling up of the carpel margins, although in some the carpels 

 remain open. 



Dr. Masters (" Teratology," p. 192) records a case of the cone 

 of Abies excelsa which normally produces only ovules. Abnor- 

 mally, however, it produces stamens in the lower scales and 

 ovules in the upper, indicating that ovules and stamens are inter- 

 changeable. 



He also records a case of Bcechia diosmcefolia^ Rudge, in 

 the ovary of which stamens were evolved instead of ovules ; and a 

 case of a hyacinth, in the ovary of which the placenta produced 

 both anthers and ovules, and cases of pollen within the ovule of 

 Passijiora, and all intermediate stages of transformation between 

 the anther and the ovule (p. 185). 



So that we appear to have here not only unity of anther and 

 ovule, but also unity of the sexes. The separation of the sexes 

 appears to be only a matter of convenience and advantage in the 

 struggle for life, two differentiated individuals producing more 

 variation in the progeny than bisexual undifferentiated individuals. 

 It stands to reason that the more distinct the individuals are 

 which bear the separate sexes, the greater will be the individual 

 variation, and the larger number of variations will result from the 

 recombination of the sexual elements. 



In the hundreds of modifications of anthers, we get that of 

 Menispermum Canadcnse, in which each i)ollen-sac is again 

 divided into two locelli hy the growth of a partition. Similar 

 partitions or so-called false dissepiments are not infrequent in the 

 ovary. The partition in the anther may be exi^lained by the 

 ingrowth of the margins of the double indusium, thus dividing 

 each anther sac into two locelli, as a carpel would divide its cavity 

 into two cells ])y the ingrowth and fusion of its margins. 



