2 LOTSY AND KUIPER, A PRELIM. STATEMENT OF THE RESULTS OF MR. 
known species of Gallus when crossed with each other, or when crossed, 
with the exception of G. bankiva, with the domestic fowl, produce infer- 
tile hybrids’. Or, even at that time, this statement was not correct, nay, 
it was in contradiction with a previous statement of DARWIN himself 
l.c. p. 246 „Out of 500 eggs raised from various first crosses and hybrids, 
between G. sonnerati, bankiva and varius, only 12 chickens were reared 
arid of these only three were the product of hybrids inter se”. Only, in the 
cade of crosses with G. lafayetti the statement as to sterility holds good, 
but it refers (1. c. p. 246) to two hybrids only, one male and one female. 
It may be mentioned here already, that one has to be exceedingly ca- 
reful when drawing conclusions as to sterility from non-succes in bree- 
ding in one or even during several seasons. External conditions: the 
way in which the animals are kept, the food given to them, the condi- 
tions of the weather, the way in which the eggs are hatched etc. etc. 
have a very great influence on the result. 
A very striking instance will be given in detail later on: in 1922, an 
exceptionally wet year, not a single egg of any of our hybrids hatched, 
while previously we had obtained even F, birds from the cross Bankiva- 
Sönhkrati, so that, if our hybrids had been sent this year to an expert 
for ‘judgement he would undoubtedly have pronounced all of them ste- 
rilé The supposed sterility of the hybrids of wild fowl, was however not 
thé ole, nor even the chief reason for DARWIN to accept Gallus bankiva 
asthé°only ancestor of our domestic fowl: In this, he relied chiefly on 
thé Many cases of reversion among domestic poultry to the plumage of 
bun Riva. How little the significance of ,reversion”” and inheritance was 
afthat'time understood, the following quotation l. c. p. 285 may show: 
„I reared several birds from the white Silk hen by the Spanish 
ay abe: all were coal black [as the father] +), and all plainly showed 
“their parentage in having blackish combs and bones; none inheri- 
7 “ed the so called silky feathers, and the non-inheritance (sic) of this 
1 Haracter has been observed by others. The hens never varied in 
their plumage. As the young cocks grew old, one of them assumed 
Yellowish- -white hackles and thus resembled in a considerable de- 
i ‘bree the cross from the [previously mentioned] Hamburgh hen; 
. ‘the other became a gorgeous bird, so much so that an acquaintance 
' “had it preserved and stuffed simply from its beauty. When stalking 
“about it closely resembled the wild Gallus bankiva, but with the 
OEE was? 
1) “words between square brachets added by us. 
