ELIOT OXALIS SUKSDORFI. 



2S5 



effect fertilization ; yet cross-fertilization between flowers of the 

 same form is effected in only about one-half the cases, as is shown 

 by some of Mr. Darwin's experiments upon other trimorphic 

 species. 



Considering that O. S/tksdorfii is an insect-fei tilized flower, 

 its great abundance can be accounted for by its excellent adapta- 

 tion to the law of chances ; and this also might be held to account 

 for the predominance of the mid-styled flowers, for in these the 

 stigma is at a point midway between the anthers (in other words, 

 the flower is the average of the other two forms), and any insects 

 over 7 mm. in length might effect fertilization. 



I make mention in closing of two abnormal flowers, or " freaks," 

 which I came upon while making m\' measurements. The one 

 was a flower of the mid-style form, and contained six stamens — 

 the sixth bearing, instead of an anther, a petal-shaped appendage. 



1 he other specimen may be best described by referring to 

 Table V. 



TABLE v. — Abnormal Flower of O. Stiksdorfii. 



MEASUREMENTS OF STAMENS AND PISTILS. 



Stamens. 



3 

 4 

 5 

 6 



7 

 8 



9 

 10 



Pistils. 



Color of Anther. 



Length. 



Bright yellow ] 9.1 



Dull yellow I 7.7 



Lighter yellow i 6.7 



Bright yellow .'. ^-8 



Buff I 6.0 



Grey 5.5 



Grey | 5.0 



Darker grey 1 4-5 



Dark grey i 4.0 



Dark grey j 4.0 



i;.o 



Both of these specimens may be illegitimate offspring of the spe- 

 cies, as similar examples in other heterostyled plants have been 

 described by Mr. Darwin, or they may be merely effects due to 

 unknown causes. 



