174 
A. D. Darbishire. 
each generation bred from the hybrids, recessives occur in the 
proportion of 25% of the whole of the generation. 
I have taken the Tables printed below from Mr. Lock’s 
valuable paper on “ The Recent State of Knowledge of Heredity 
in Pisum,” 1 and incorporated my own published observations 2 on 
this point. 
Generation. 
Observer. 
No. of Yellows. 
No. of Greens. 
% of Greens. 
F., 
Mendel ... 
6022 
2001 
24-9 
Correns ... 
1394 
453 
24-5 
Tschermak 
3580 
1190 
24-9 
Bateson ... 
11903 
3903 
24-7 
Hurst 
1310 
445 
25-4 
Lock 
1438 
514 
26-2 
Darbishire 
4015 
1394 
25-8 
P 3 
Correns ... 
1012 
344 
25-5 
Tschermak 
3000 
959 
24-2 
Lock 
3082 
1008 
24-6 
Correns ... 
225 
70 
23-7 
Lock 
2400 
850 
26-1 
Mendel continued the experiment with cotyledon colour through 
six generations, but on a small scale, and he does not give any further 
information than that “ no departure from the rule has been 
perceptible.” It is to be supposed that he recorded the numbers of 
yellows and greens, but did not think them of sufficient interest to 
warrant their publication. I shall have occasion to revert to this 
highly important fact later. 
For the present I am only concerned to point out that all the 
evidence we possess as to the proportions in which the recessive 
member of the pair of characters we are at present dealing with 
occurs, is contained in the Table given above. Now the expectation 
based on Mendel’s theory is that hybrids will continue to produce 
recessives in these proportions to infinity. But so closely have 
Mendelian fact and hypothesis become associated that some of those 
1 Ann. R. Bot. Gard. Peradeniya, IV., 1908, p. 93. 
* Proc. Roy. Soc. B., Vol. 81, p. 70 and p. 78. 
