334 The Journal 
Darwin’s ‘‘Animals and Plants,” (1) 
Mendelian dominance (2) sex-limited 
Mendelian inheritance or (3) predomi- 
nance as a group of the characters of one 
parent over those of the other. In 
other cases it may mean only (4) a high 
degree of excellence as regards some 
inherited character or the ability to 
transmit the same. 
BREEDERS’ EXPLANATIONS 
If we go a little farther and inquire 
what explanations the breeders have 
offered for the various results that they 
lump together under the name of indi- 
vidual prepotency, we find these: 
1. “Maximum efficiency of all 
organs,”’ as indicated “in the expression 
of the countenance and in the general 
bearing, behavior and carriage,’’! or, ina 
word, vigor. 
2. Existence of the breed for a long 
period of time ‘“‘on a favorable soil.’” 
3. Length of time in which a variety 
or breed has been under domestication. 
“Tt is generally assumed that an old 
species or variety is prepotent over a 
more recent species or variety.’’ 
4. Mutation. ‘High prepotency does 
not arise through normal variation, but 
must rank as a heritable sport or aber- 
rant variation.’’* 
5. Accompaniment of a mutation. 
“In nature, prepotency may arise spon- 
taneously and abruptly along with 
sports in one or more directions.’ 
6. As a result of natural selection, 
of Heredity 
through a gradual process of evolution.® 
7. Inbreeding. 
8. “Purity of blood.” 
9. Sexual development.’ 
10. “The lack of affinity in certain 
characters, which makes it difficult to 
blend them.’’’ 
11. Telegony.® 
12. Maternal impression.” 
13. Physiological relation between 
dam and offspring, which is supposed to 
make the dam prepotent over the sire.!! 
14. Relative maturity of parents, old 
animals being thought to be prepotent 
over very young ones.” 
15. Degree of ripeness of germ-cells, 
fully mature gametes being prepotent 
over immature gametes." 
16. Relative strength of ‘nervous 
organization” —whatever that may 
mean. 
17. Degree of functional develop- 
ment, either of an individual or of his 
immediate ancestors. 
Certainly we have here a beautiful 
example of a term that means all things 
to all men. Some writers regard it 
clearly as a function of individual 
characters, others regard it clearly as a 
function of individual animals, others 
do not stop to ask what it does mean; 
others look on it as a highly variable 
quantity, as J. Cossar Ewart, who 
says :16 
‘“‘An animal (male or female) may be 
prepotent in some respects and not in 
1 Marshall, F. R. Breeding Farm Animals, p. 90. Chicago, 1911. 
2 Von Oettingen, B. Horse Breeding, p. 222. 
London, 1909. 
3 Ewart, J. Cossar. The Pennycuik Experiments, p. xii. London, 1899. 
4 Galton, Francis. Nature (London), July 14, 1898. 
5 Ewart, op. cit., p. 44. 
6 Thid. 
7 Cf. Dexter, William Hart. Methods Used by the American Jersey Cattle Club in Perfecting 
the Breed. In A. B. A. Proc. IV (1908), p. 37: “‘ Prepotency will be shown in the general appear- 
ance, which should be thoroughly masculine in character, with a harmonious blending of the parts 
with each other. There should be evident vigor, style, alertness, and a resolute appearance with 
abundant nervous energy.” 
8 Shaw, Thomas. Animal Breeding, p. 105. New York, 1901. 
9 Thid. 
10 Or even ‘‘paternal impression’! A genealogist writes me with reference to the Brigham 
Young photographs: “I fancy that I can see that the force of affection, which may exist in the 
heart of either parent at the time of creation, determines where the likeness will fall. . . . The 
one who loves the most copies in the offspring the features of the one loved.” 
11 Mentioned by Davenport, E. In Breeders’ Gazette, vol. lx, p. 82. Chicago, 1911. 
12 Ewart, J. Cossar, Address to Zoological S2ction, British Association, 1901; quoted by Reid, 
G. Archdall. The Principles of Heredity, p. 69. New York, 1905. 
13 [hid. 
14 Cited by Davenport, E. Principles of Breeding, p. 568. Boston, 1907. 
16 This is the idea developed by C. L. Redfield in Dynamic Heredity (New York, 1915) and 
elsewhere. 
16 The Pennycuik Experiments, p. 44. 
i dn, Yee ee, De oO 
