320 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 
The flowers on one of the derivatives, as they may be called, were so 
completely lacking in color as to be a cream-white, this derivative 
being designated as albida, while the other showed some marginal 
color and a rusty tinge and was designated as rufida..... Seeds of 
the original two derivatives were sowed in the greenhouse. But one 
plant of albida, the most extreme departure, survived, while four of 
rufida were secured.”” MacDougal compared these second generation 
seedlings with seedlings from the original stock of the species, noting 
differences in size and margin of leaves, length of petioles and number 
of marginal glands. He found that the differences shown by the first 
generation appeared again in the second generation. Striking as these 
results appear it must be admitted that it would be difficult, on account 
of the small numbers of individuals differing from the parent type, to 
prove satisfactorily to the biometrician that they were not mutations 
which would have occurred regardless of the ovarial treatment. 
What appear to be germinal variations in the tomato have been 
induced by intensive feeding. T.H. White tested the effect of dried 
blood, dissolved phosphate rock, sulphate of potash and iron filings 
all in excessive amounts, and (with the exception of the iron) in 
various combinations, on the Red Cherry tomato. The lack of data 
on control cultures of seedlings from the same parent as the experi- 
mental cultures makes it impossible to compare the actual amount 
of permanent variation produced. T. H. White states that measure- 
ments ‘‘show that the plants of the sixth generation grown under the 
influence of the dried blood are one-third larger in height, length of 
leaf and size of fruit, than those of the second.” The author con- 
cludes that “there can be no doubt . . . . that, in the case of Red 
Cherry treated with dried blood, there is permanent variation to the 
third generation.” If these results are corroborated by more care- 
fully planned and rigidly controlled experiments they will add the 
weight of scientific proof of a principle in plant breeding long since 
recognized on empirical grounds, to wit, that the introduction of wild 
plants into intensive cultivation induces variation. Furthermore, it 
suggests a possible means for rapid permanent improvement of wild 
forms with which hybridization may be impracticable. 
In experiments on lower animals, e.g., the protozoa, the same 
difficulty is met with as has been encountered in bacteria and yeasts, 
in that it is manifestly impossible to distinguish between somatic and 
germinal variations. Moreover, in most of these experiments, as with 
most of those on higher animals, the necessary conditions for rigid 
