188 REPORTS ON THE STATE OF SCIENCE.—1912. 
chromosomes, instead of forming the ordinary eight synaptic groups, 
were irregularly fragmented and scattered on the mitotic spindle, some 
of the chromatin masses being much shialler, others much larger, 
than the normal synaptic chromosomes. Previous to this division it 
appeared that the spermatogonia in the testes were perfectly normal, so 
that we must ascribe the abnormality of the spermatozoa, and the con- 
sequent sterility of the hybrids, to the incapacity of the chromosomes 
derived from the two parents to form synaptic pairs. These results 
will shortly be published in detail in the ‘ Q.J.M.S.’ 
Further observations on sterile hybrids are being made in the case 
of some birds presented by Mrs. Haig Thomas, which have been kept 
for varying times in my aviaries-and some of which are still alive. 
Investigation of the sterile male shows similar features to those observed 
in the case of the pigeon-dove hybrids, but other observations on 
sterile females and another male hybrid are not complete. The sterile 
female hybrids show a partial assumption of cock’s plumage, and this 
is probably correlated with the atrophy of the ovary, since I have 
collected within recent years several examples of this phenomenon, 
which will be described when the observations are complete. 
On the Inheritance of the Spurred Condition in the Domestic Hen.— 
The object of this investigation is to attempt to discover if the inheri- 
tance of spurs in the hen could be explained on the same lines as the 
inheritance of the horns in horned breeds of ewe. ‘The difficulty of 
this breeding experiment lies in the fact that the birds have to be 
kept alive for at least a year, and for more to be on the safe side, 
before it can be settled whether a given female is going to develop 
spurs or not. In consequence the experiment has not yet been going 
on long enough to speak with any certainty, but the following crosses 
have been made :— ae 
Normal g x Spurred 9 8 
F, Normal Cock (Four Hens died) 
F, Cock x P Spurred 98 
F, Six Normal Cocks and Vive Non-spurred Females 
Although the numbers are small, it was expected that half at least 
of the F., females would be spurred. Now three of the F, cocks have 
been crossed with the F, females, and there are about twenty-five 
chicks being reared, but it is not yet possible to see if any of them will 
develop the spur. This should appear in six months’ time. 
On the Inheritance of Extra-Toe in the Fowl.—Since the first male 
parent used in the above experiment showed the abnormality of extra- 
toe, crossings have been made to deal with the inheritance of this 
character. Two distinct strains of extra-toe differing in the position 
and size of the extra-toe have been detected, and their inheritance 
is being tested against one another. Crossings of what would be 
ordinarily called extracted recessives—i.e., four-toed g x four-toed 9 — 
have given about ten per cent. of five-toed progeny. An extracted 
four-toed hen of one strain of extra-toed race, crossed with a five-toed 
