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Dl D. FÉNYES 
derate), and 1 black (or bad), specimens amongst the produce, or, on the 
average, a stock, each specimen of which exhibits above-named qualities 
in the same proportion in itself. 
A more natural interpretation than usual, of the significance of 
heredity, atavism or reversion, and variation is desirable. It is usual to 
consider the qualities of the individual from three standpoints ; (1) the 
properties of the produce, so long as they resemble the average of those 
of the parents and more remote ancestors, are looked upon as «heredity»; 
(2) the qualities of the progeny, in so far as they deviate from the average 
and are found similar to the characteristics of one or more predecessors, 
when compared with the latter, are considered as «atavism or reversion»; 
(3) the different degrees of the deviations of the full brothers and sisters 
compared to the average, but without taking into account the properties 
of the parents and more remote ancestors, are generally called the «variation»- 
No hard and fast line can be drawn between heredity, atavism or reversion 
and variation, and the distinctions of these would create confusion just 
for the very reason, that heredity is nothing else but the series of chances 
of probability, which bring out the properties of the parents and more 
remote ancestors in the individual ; consequently, the chances of the in¬ 
heritance of the qualities which deviate from the average to different 
degrees or to the extremes, — chances, which are rarer, of course, than the 
average, — the atavism or reversion and variation — are to be classed 
under heredity also. 
Henceforth, white will be recessive, grey dominant, and black also 
recessive. When, according to Mendel and his followers, — 
a) Pure-bred grey and pure-bred white are crossed, all the hybrids, 
without exception, will be grey (uniform, Land) and hétérozygotie. The 
produce of the inter se matings of these full brothers and sisters will be, 
as regards their outer appearance, of two kinds, viz., greys (dominant) 
and whites (recessive), and will show a 3: 1 ratio ; amongst these hybrids 
of the second generation, one-third of the greys will be homozygots and 
two-thirds heterozygots, and all the whites, homozygots. — The ho¬ 
mozygots are constant, they breed true, like the pure breeds, while, on 
the other hand, the progeny of the heterozygots (like the progeny of 
the hybrids of the first generation) will again show the grey : white = 3:1 
ratio. 
ß) Pure-bred white and pure-bred black are crossed, all the hybrids 
will be, without exception, uniform grey, and hétérozygotie. From the 
inter se matings of the hybrids of this first generation, there will result 
three kinds of hybrids of the second generation, which are also externally 
different, viz., whites (recessive homozygots) : greys (dominant hetero- 
