18 THE JouRNAL OF HEREDITY 
All of the Asiatic varieties of chestnut 
so far known are small trees and prob- 
ably slow growing. The Chinese chest- 
nut, or at least the variety shown in 
figure 1, bears nuts that are about the 
size of the American chestnut, or a 
trifle larger, and of a delicate, sweet 
flavor and fine texture. The Japanese 
varieties are also small trees and in 
general have large, coarse nuts, with a 
bitter adherent inner skin; but there 
appear to be some strains that are sweet. 
No European varieties have yet been 
found that are appreciably resistant. 
Perhaps the greatest desideratum at 
‘this time is a resistant tree of the forest 
type. But this may yet be found, as 
the world-species of Castanea are not 
yet assembled. 1 
How much easier it would have been, 
and how much loss could have been 
avoided if importation of nursery stock 
had been safeguarded in time to have 
excluded this latest addition to our 
collection of foreign diseases and pests. 
Prevention is cheaper than cure; this 
is the first great lesson to be learned 
from the invasion of the chestnut bark 
disease. It is too late to exclude this 
undesirable citizen; but we can at 
least redouble our efforts to see that no 
others get a foothold on this continent. 
Inheritance of Milk Yield 
Inheritance of the property of milk production in a registered herd of cows in 
East Prussia is discussed by J. Peters in Nos. 11, 12 and 13 of the Deutsche Land- 
wirtschaftliche Tierzucht, Hannover, Germany, 1913. His data show great 
variations in the inheritance of milk yield. The offspring of the best mothers 
yielded, on the average, the most milk and those of the inferior mothers least. 
_The range of variation was not, however, so great among daughters as among 
imothers. First class cows produced both good and inferior offspring, and vice 
‘versa. The inheritance varied around a center, which was somewhat higher in the 
‘daughters of superior mothers than in those of inferior cows. The magnitude 
of the variation was the same for all classes. 
_ Peters then determined the milk production of the grandparents and of the 
‘separate families of the herd. With regard to the families, he found that some 
‘produced relatively many good animals, while the descendants of others were 
usually inferior cows; in other families, again, he observed unusually large varia- 
tions in the performance of the offspring. As a rule, however, the offspring of good 
families were good.milkers and those of inferior families unsatisfactory. Inheritance 
varied in the case of mediocre families. 
The writer comes to the conclusion that it is not sufficient to estimate the absolute 
and relative yield of cows, and upon these data to select the offspring of the best 
individual performers for further breeding, but it is necessary to select the best 
families, for among the descendants of these will be found the largest number of 
good milch cows. His data are summarized in the Bulletin of the International 
Agricultural Institute, Rome. 
The Improvement of the Human Race 
The improvement of the breed of mankind is no insuperable difficulty. If every- 
body were to agree on the improvement of the race of man being a matter of the very 
utmost importance, and if the theory of the hereditary transmission of qualities 
in man was as thoroughly understood as it is in the case of our domestic animals, 
I see no absurdity in supposing that, in some way or other, the improvement would 
be carried into effect—Francis Galton, in Macmillan’s Magazine (1865). 
