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Allen . — Nuclear Division in the 
I have just mentioned show that, although in many instances it holds with 
greater or less exactness, it is very far from being universal. It should be 
noted also that even in cases which are classed as illustrations of 
dominance, as Correns (’03 a , ’03 b) has pointed out, the dominant quality 
by no means always appears in the offspring in the intensity which was 
characteristic of the dominant parent. Thus, Mendel says that ‘ the hybrid 
character resembles that of one of the parental forms so closely that the 
other either escapes observation completely or cannot be detected with 
certainty.’ This is illustrated by the colour of the embryo in the Matthiola 
crosses of Bateson and Saunders (’02), in which green usually appeared 
to be the dominant colour, but was often much diminished in the crosses. 
A series of such facts might be collected, which would show every 
conceivable gradation between the complete dominance of one parental 
quality and the appearance of an exactly intermediate character in the 
offspring. Nevertheless, the frequently-occurring fact of dominance, taken 
in connexion with the reappearance of the recessive character in the next 
generation, is important as showing that the physical bases for two more 
or less antagonistic qualities may exist side by side in the same nucleus 
without any such interaction as materially affects the nature of either. 
Considering the cross-bred individual as a whole, it constitutes a 
complex of qualities, some of which may approach, or be identical with, 
the corresponding qualities of the father ; others bear a like relation to those 
of the mother, and still others are intermediate between, or even entirely 
different from, the corresponding qualities of either parent. As a result 
of the summation of all these various qualities, the offspring occupies, in 
general, a position intermediate between the respective parents. In the 
simplest possible case — that, namely, in which the parents differ in only one 
quality — if dominance occurs with respect to that quality, the offspring 
exactly resembles one parent. The same result may follow in more 
complicated cases, provided all the characters of one parent in respect to 
which the parents differ happen to be dominant. This, however, becomes 
less probable with an increase in the number of differences between the 
parents. The possibility of an exact resemblance between the hybrid and 
one parent may be illustrated by the much-discussed ‘ false hybrids 5 of 
Millardet (’94). The fact that these hybrids breed true may be due to 
what we may term a permanent dominance, as distinguished from the 
ordinary (Mendelian) form ; or it may result from a complete disappearance 
of one set of characters, due to something like a destruction or extrusion 
of one parental idioplasm. 
It will naturally be expected that whatever balance may be struck 
in one case as the result of the combined action of two idioplasms will 
appear in other cases in which, under substantially similar conditions, the 
same or similar idioplasms come into a like relation. This implies that 
