Chap. IV. OXALIS REGNELLI. 173 



We here have the remarkable result that every one 

 of 138 legitimately fertilised flowers on the three forms 

 yielded capsules, containing on an average 11 '33 seeds. 

 Whilst of the 255 illegitimately fertilised flowers, only 

 6 yielded capsules, which contained 3 • 83 seeds on an 

 average. Therefore the fertility of the six legitimate 

 to that of the twelve illegitimate unions, as judged 

 by the proportion of flowers that yielded capsules, is 

 as 100 to 2, and as judged by the average number of 

 seeds per capsule as 100 to 34. It may be added that 

 some plants which were protected by nets did not 

 spontaneously produce any fruit ; nor did one which 

 was left uncovered by itself and was visited by bees. 

 On the other hand, scarcely a single flower on some 

 uncovered plants of the three forms growing near 

 together failed to produce fruit. 



Oxalis Regnelli. — This species bears white flowers 

 and inhabits Southern Brazil. Hildebrand says that 

 the stigma of the long-styled form is somewhat larger 

 than that of the mid-styled, and this than that of the 

 short-styled. The pistil of the latter is clothed with a 

 few hairs, whilst it is very hairy in the other two 

 forms. The diameter of the pollen-grains from both 

 sets of the longest stamens equals 9 divisions of the 

 micrometer, — that from the mid-length stamens of the 

 long-styled form between 8 and 9, and of the short- 

 styled 8, — and that from the shortest stamens of both 

 sets 7. So that the extreme difference in diameter is 

 as 9 to 7 or as 100 to 78. The experiments made by 

 Hildebrand, which are not so numerous as in the last 

 case, are given in Table 28 in the same manner as 

 before. 



The results are nearly the same as in the last case, 

 but more striking ; for 41 flowers belonging to the 

 three forms fertilised legitimately all yielded capsules, 



