ON BIASTREPSIS IN ITS RELATION TO CULTIVATION. 169 



Otherwise straight. One of these showed well-marked twisting in 

 one of the lateral branches. Hence only four plants out of nineteen 

 (about 20 per cent.) showed slight and local twisting of the stem; 

 that is, just the same proportion as that of typically twisted stems 

 occurring in a control-experiment^). These four plants flowered in 

 isolation and ripened seed before September 15, 1893; that is, within 

 a year from the time of sowing. 



Tne effect of the method of culture described above is that, in 

 these artificially annual plants, whilst twisting of the stems is not 

 altogether prevented, it is reduced to a minimum. 



Sowing of September 15, 1893. The seed of one of the previously 

 described artificially annual plants was immediately sown, and 

 germination took place under the same conditions as in the previous 

 year. Tne seed-bearing plant was the one which showed twisting 

 in one of its lateral branches. At the end of January the plants were 

 brought out of the greenhouse and were kept for a time under glass. 

 Two weakly plants remained in the rosette-stage, but the others, 

 thirty-five in number, threw up shoots in May: the shoots were 

 vigorous, of about the same height and thickness, and were better 

 and more uniformly developed than were those of the preceding 

 generation. The examination of them on June 18 gave the follo- 

 wing results: — 



Nine normal decussate shoots; 



Ten decussate shoots, each having one four-leaved whorl; 



Three shoots with two four-leaved whorls; 



One shoot with three four-leaved whorls; 



One shoot in which the leaves of one of the pairs were separated. 



Eleven shoots with slight local twisting (30 per cent.). 



The result is thus the same as that obtained with the preceding 

 generation. I was unable to allow these plants to flower, for fear 

 of interfering with the normal cultivation of the breed. 



Sowing of September 3, 1894. Professor 0, Le Monnicr of Nancy, 

 who has for years cultivated my breed of Dipsacus on a larger scale 

 than I have myself been able to do, was good enough to send me 

 some fresh!y-gathered seed of twisted individuals early in Sep- 

 tember, 1894. In the more southerly climate of Nancy the seed had 



i) It should be remarked that in the control- experiments only the 

 entirely, or a most entirely, twisted stems are counted: no attempt was 

 made to ascertain whether or not slight local twisting of the stem would 

 develop in the other plants, for most of these were dug up before they 

 had completed their growth. 



