Referate. 299 
and their presence only in the males of Gallus has sufficed to bring about 
their suppression in the hybrids even though the latter are male. The 
frequent recurrence of reddish-brown or brown mottled with black in the 
plumage of such hybrids as guinea >< chicken, pheasant >< chicken, and 
eacock >< chicken, is presumably a return to a condition such as exists 
in Gallus ferrugineus or in still more primitive types such as Polyplectron 
chalcurus. If one could express the whole matter in one phrase it would 
be that the return in each regressive feature seems to be more to primitive 
fundamental states or conditions common to a number of allied groups 
than to any particular recognizable ancestor.” 
There are several difficulties in the way of unreservedly accepting 
these conclusions. In the first place the whole reasoning is deductive. It 
would be quite possible for another person to take the same data and 
with a different viewpoint reach totally different conclusions. More speci- 
fically there are several points in doubt. Thus the author throughout 
discusses the pattern shown by these hybrids as though it were a true 
barred pattern, though as a matter of fact the description and figures 
given shown plainly that it comes much closer to the type of pattern 
known technically to poultry fanciers as crescentic pencilling than to true 
barring. The objection might be raised that this is mere verbal quibbling: 
that the two patterns which the poultryman calls respectively barring and 
pencilling are fundamentally the same. The difficulty is, however, that 
it is easily possible to show by definite experiment (as has been demon- 
strated in the reviewer's laboratory) that these two pattern types behave 
as distinct and different characters in inheritance. Furthermore the author 
is apparently not aware of the fact that there are at least three (and 
possibly more) types of true barring to be found in the plumage patterns 
of domestic poultry, all of which types behave differently in inheritance, 
although they are superficially quite similar. Again the meager number 
of the hybrids and the fact that they are all in one direction and of the 
same sex (i. e., there are no reciprocal guinea d >< chicken 2 crosses) makes 
the conclusion that we have a true case of reversion here seem somewhat 
hasty in view of the fact that certain ones, at least, of these plumage 
patterns in poultry are being found to be inherited in a sex-limited manner’). 
In such cases totally different conclusions as to probable atavism would 
be reached according to the direction in which a cross was made if only 
one direction were experimentally tried. To attribute the condition of 
character exhibited by a hybrid to reversion and to make deductively a 
plausible case for the truth of such a contention is not difficult, especially 
where the color patterns of Gallus are involved?). But does this get us 
much ahead? Interesting and valuable as are records of hybrids such as 
Guyer sets forth in the paper under review as statements of fact, may not 
the clear and definite analysis of the breeding pen be more surely and 
safely depended upon for their interpretation than a deductive appeal to 
phylogeny ? Raymond Pearl. 
1) Cf. Pearl, R., and Surface, F.M. On the Inheritance of the Barred Color 
Pattern in Poultry. Arch. f. Entwicklungsmech. 30 1910 (Roux Fest-Band) I. Teil, 
PP- 45—61. 
2) It is possible by careful examination to find single feathers on a Black-breasted 
Red Game 9, each of which seems to show an approximation to some one of the well 
known types of color pattern of poultry (e. g., barring, pencilling, lacing, stippling, etc.) 
and from a single bird of the sort named feathers representing practically every one 
of these known pattern types may be obtained. 
