74.4 Michael F. Guyer 
The supposition that old characters reassert themselves does 
not necessarily imply that they have been lying dormant in an 
isolated particle in the germ-plasm for a series of generations. It 
is just as possible that, as regards their objective expression, they 
have simply been obscured as the result of more recently devel- 
oped modifications in their own substance. Or again, it 1s equally 
plausible to suppose that the earlier expression was the result of 
the union or special grouping of certain complimentary elements 
which have become separated or deflected by the newer acquisi- 
tions of the species and that with the suppression of these later 
additions the older groupings have been restored. 
It is evident how this could be true particularly with such fea- 
tures as color where a very slight physical or chemical change 
might be optically expressed as a very pronounced difference in 
the color pattern. ‘Thus the arrested development of a green- 
making superstructure may yield a yellow instead of green color. 
Indeed with apparently slight alterations one may get as great 
contrasts as red and green, as illustrated in certain parrots where, 
while the adult males are intensely green, the young males are red, 
resembling more the females, which are bright red. 
Again, gloss and iridescence of feathers, it is known, are a 
matter of the structure of the horny coating of the feather rather 
than one of pigment. Since this physical structure is not exactly 
the same in the different species of birds that exhibit the phenom- 
ena, even where both ancestors of a hybrid have much iridescence 
the hybrid itself may be of plain dull colors, an example of which 
I have before me, in a peacock-chicken hybrid. One can only 
conclude, therefore, that the two different types of structure have 
annulled one another. Of all the hybrids of markedly divergent 
parentage which I have examined, in fact, not one shows more 
than a faint trace of iridescence although most of them as peacock 
* chicken, and pheasant X chicken, have progenitors on each 
side which display it to a considerable degree. 
In the guinea-chicken hybrids, as we have seen, all the parental 
ornamentations of head and plumage have been suppressed. In 
color, only certain fundamental pigments and structures in‘ a 
measure common to both groups have appeared, fdr the most 
