322 LOCK: STUDIES IN PLANT BREEDING 
(5) MendeVs Paper on Hieracium . 
Mendel himself showed in a later paper (translation 
Bateson (2)) that the results which he obtained in the case 
of seven pairs of characters in peas are not universally 
applicable. As the result of experiments in crossing different 
forms of the genus Hieracium he came to the following 
conclusions :— 
The characters of the hybrids were, as a rule, more or less 
intermediate between those of their parents, although in 
some cases there was partial dominance. Hybrids arising 
from the same cross were not always identical in appearance. 
In further generations, which resulted from self-fertilized 
hybrids, the pure parental characters did not appear, but the 
offspring agreed in appearance both with each other and 
with the hybrid plant from which they were derived. 
In cases such as this it seems clear that the simple form of 
Mendel’s Law is not followed. 
11.—REGENT CONFIRMATORY OBSERVATIONS 
AND CRITICISMS. 
There has already been occasion to allude to the simul¬ 
taneous confirmation of Mendel’s observations afforded in 
1900 by the publication of the work of de Vries, Correns, 
and Tschermak. Among other observations in the same 
direction may be mentioned those of Spillman (41) with 
wheat, Hurst with orchids (40), and Emerson (34) with 
kidney beans. Biffen (8) has confirmed many of Spillman’s 
results, and his discovery that in the case of wheat suscepti¬ 
bility to, and immunity from, disease behave as allelomorphic 
characters and obey Mendel’s Law, the former being domi¬ 
nant, is of special interest from a practical point of view. 
Miss Saunders (6) found a Mendelian behaviour in 
Lychnis, Atropa, Datura, and in a considerable number of 
cases in crosses between hairy and glabrous races of 
Matthiola, but in some of the latter certain exceptional or 
