sept. 15,1924 Effect of Feeding Thyroid on Plumage of the Fowl 
287 
COMPARISON OF NEW FEATHERS IN THYROID - FED BIRDS WITH THOSE OF 
NORMAL BIRDS 
Cape 
AVing Bow 
Saddle 
Normal birds. 
Exposed portion generally 
red, base black; red may 
occupy whole distal half 
of feather or be reduced to 
a border. Distinctly 
pointed; with broad zone 
of free barbs. 
Similar to cape but occasion¬ 
ally with black spot at 
tip. Same general shape, 
but shorter. 
Varying from almost wholly 
red to red with black 
middle stripe. Long 
(some 12 cm.); narrowly 
attenuated distally; 
pointed. AVide zone of free 
barbs. 
Bird No. 441.. 
Black, with definite red stip¬ 
pling near tip. Broadly 
rounded, without zone of 
free barbs. 
Black with a considerable 
quantity of red more or 
less irregularly inter¬ 
mixed; tendency to stip¬ 
pling. Broadly rounded, 
without “free zone.” 
Black with considerable red 
irregularly distri b u t e d. 
Elongate (11 cm.) but 
broad, and rounded at tip; 
very little “free zone.” 
Bird No. 440_. 
Black; little if any red. 
Broadly rounded; with¬ 
out “free zone.’' 
Black. Broadly rounded; 
without “free zone.” 
Dull black with some ir¬ 
regular red; tendency to 
stippling. Broad, rounded, 
without “free zone”; 
length 8 cm. 
Bird No. 444__ 
Mostly black; a few feathers 
with a small amount of 
red on margin. Bluntly 
rounded; without “free 
zone." 
Black with small amount of 
red, showing tendency to 
stippling. Bluntly 
rounded; no “free zone.” 
Black (no red). Elongate 
(11 cm.); with somewhat 
the taper of male saddle 
feathers but broader and 
rounded at tip; narrow 
“free zone” near tip. 
Old male_ 
Black or black with little 
red. Broadly rounded; 
without “free zone.” 
None available. (This bird 
pulled the new feathers he 
could reach as they grew.) 
None available. 
LITERATURE CITED 
(1) Cole, L. J., and Lippincott, W. A. 
1919. THE RELATION OF PLUMAGE TO OVARIAN 
CONDITION IN A BARRED PLYMOUTH ROCK 
PULLET. Biol. Bul. 36: 167-182, illus. 
(2) Crew, F. A. E., and Huxley, J. S. 
1923. THE RELATION OF INTERNAL SECRETION 
TO REPRODUCTION AND GROWTH IN THE 
DOMESTIC FOWL. I. EFFECT OF THYROID 
FEEDING ON GROWTH RATE, FEATHERING, 
and EGG production. Vet. Jour. 79: 343- 
348. 
(3) Goodale, H. D. 
1916. GONADECTOMY IN RELATION TO THE 
SECONDARY SEXUAL CHARACTERS OF SOME 
domestic birds. 52 p. illus. Washington,. 
D. C. (Carnegie Inst. Wash. Pub. 243.) 
(4) - 
1916. A FEMINIZED COCKEREL. JOUT. Exp. 
Zool. 20: 421-428, illus. 
(5) - 
1918. feminized male birds. Genetics 3: 
276-298, illus. 
(6) Torrey, H. B., and Horning, B. 
1922. HEN-FEATHERING INDUCED IN THE MALE. 
FOWL BY FEEDING THYROID. PrOC. SOC- 
Exp. Biol, and Med. 19: 275-279. 
