2 -. Cc. H. DANFORTH 
C. Polydactyly. For the sake of convenience three grades of 
polydactyly, corresponding essentially to those designated by 
Anthony (’99), were employed. Grade 1 includes cases in which 
only the distal phalanx is involved; grade 2 includes cases 
where two phalanges are involved but with the toes usually 
more or less united and equal; grade 3 includes all cases of a 
more pronounced form. In grade 3 the metatarsal is also 
affected and the accessory toe generally has three phalanges. 
Only one instance of six toes occurred. Occasional specimens in 
which there were really only four toes but in which the first 
digit showed three phalanges instead of two were classed as 
polydactyl, grade 1. Such individuals were included because 
the evidence seems to the writer to indicate that polydactyly 
in the fowl is not so much a matter of added elements as of 
readjustments following early hypertrophy of a single anlage. 
In possibly a third of the cases the two sides were not strictly 
symmetrical. Of the 28 polydactyly chicks that hatched, 8 
were of grade 1 and 10 each of grades 2 and 3. The father 
‘was of grade 2 (on the left side only). 
As shown by Kufmann-W olf (’08), some cases of polyadactyly 
can be recognized as early as the fifth day of incubation. Prob- 
ably all individuals which would develop info grade-3 speci- . 
mens can be recognized as polydactyl at this age. But for 
purposes of the present record no individual under seven 
days is included. Of 220 chicks and embryos of 7 days and 
over, 147 were normal, 73, or 33 per cent, were polydactyl. 
If polydactyly behaved as a strictly dominant character the 
expectation in this case would be 50 per cent. The failure of 
polydactyly in poultry to give typical Mendelian ratios has 
been discussed by several authors, especially Davenport (’09). 
D. Booting. In chicks that are to be booted, feather (down) 
rudiments generally become apparent on the tarsi during the 
eleventh day of incubation (fig. 2) or considerably later than on 
other parts of the body. After the twelfth day, booting is 
easily recognized. Thirty-six living chicks which were booted 
were classified into three grades, based upon the amount of down 
on the tarsi. Grade 1 represents individuals with from one 
