142 BROOKLYN BOTANIC GARDEN MEMOIRS 
wholly self-sterile the second season, when grown in Brazil. One 
may assume, I think, arguing from data of similar character, that this 
progressive result was not due to actual inheritance of an acquired 
character but rather to the fact that the first generation in each case 
passed a portion of its life cycle in the original environment. 
Similar results were obtained in the case of Abutilon darwinit, 
which though self-sterile in its native Brazil, became moderately self- 
fertile late in the first flowering season in Darwin’s greenhouse. 
Darwin made more detailed experiments on Senecio cruentus, 
Reseda odorata and Reseda lutea and found, as he believed, that each 
plant though self-sterile was cross-fertile with every other plant. 
His pollination experiments with Senecio cruentus and Reseda lutea 
were so inadequate that they may be omitted from consideration; it 
was really his experiments on Reseda odorata that were thought te 
establish the fact of complete cross-fertility. 
DARWIN’S EXPERIMENTS ON Reseda odorata IN 1868 
Male Parents 
Ae panG pn pe) ee 
Aa cS eae. | 
BuleealeS: Alcala | 
g 0 | — —  — — _— 
gC ie aS. Ee Es | 
3 eo | ee | en, ee 
OD Nase |S fete || Sea 
30 
St JB TR. WS 1 eS | 
oO 
jew | | 
F | S45 
G | Ss: 
Only sixteen cross matings were made, however, and this is not 
sufficient to prove the point, as is shown by one of our own experi- 
ments, where I13I cross-matings were made with only 4 cases of cross- 
sterility. From the fertile cross-pollinations Darwin raised four 
plants in 1869. Three of these proved to be self-fertile and one self- 
sterile. Six more plants were grown in 1870. Of these, two were 
almost self-sterile and four were almost completely self-fertile. The 
former produced altogether five seeds from self-pollinations, and the 
resulting plants proved to be self-sterile like their parents. These 
varied results Darwin attributed to a difference in inherited sexual 
constitution, but it seems to me that this conclusion should be ques- 
tioned. Our own results have proved conclusively that toward the 
