[Fi-om ‘The Auk,’ Vol. V, No. 2, April, 1888.] 
Polydactylism in Birds. 
To the Editors of the Auk : 
Sirs :—My attention has been directed to a short article in ‘The Auk’ 
(Vol. IV, No. 4, pp. 331-333, Oct. 1887), on ‘Ornithological Curiosities.— 
A Hawk with nine toes, and a Bobolink with spurs on its wings.’ Ido 
not profess to be an ornithologist, though much interested fin the subject, 
and something of an observer of bird life; I prepare this note as a teratol- 
ogist. lam much pleased with the report of the cases of the supernu- 
merary development by Mr. Henry K. Coale, and hope his example will 
be followed by others from numerous observers all over the land. 
In my somewhat extensive reseai’ches for the purpose of collecting and 
classifying the bibliography and references relating to the ‘The Material 
of Teratology,’ I have been surprised at the infrequency as well as the 
meagreness of reports, and the almost absence of even incidental men- 
tion of cases of supernumerary and duplex development in birds. Such as 
are found are almost exclusively such as occur in domesticated fowls. I 
have been disposed to belie ve that ornithologists are inclined to ignore 
malformations and monstrosities as unworthy of study, or even mention, 
and that they have cast aside the specimens which have presented them- 
selves to their casual notice, as one would an imperfect example in any 
other department of natural objects. 
I desire to invite the co-operation of all classes of ‘bird men’—sports- 
men, collectors, and scientific ornithologists—in procuring and reporting 
all cases of double monsters, or of supernumerary development, in any de- 
gree in which it may be found in any species of the feathered tribes. I 
am quite certain that ‘The Auk’will be a proper medium of communi- 
cation—under the head of Teratological Notes—or Ornithological Tera- 
tology. 
Ulysses Aldrovandus, wrho was a celebrated ornithologist, and a volu- 
minous writer on the subject two and a half centuries ago, gives us many 
illustrations of double monstrosities, extra legs and extra toes in various 
species of birds. These are chiefly found in his special work ‘Monstro- 
rum Historian!,’ a ponderous folio, published sumptuously in 1642. The 
pages 549 to 570 are occupied with descriptions of cases of extra limbs in 
birds, under the title ‘Multiplicatio pedvm in foetivs avivm ,’ and is 
illustrated with seventeen figures. The cock of the common fowl on 
page 560 has two extra toes attached to his left leg. 
Otto, in his great work, ‘Monstrorum Sexcentorum Descriptio-Anatom- 
ica,’ grand folio, 1841, describes (No. 473) a chicken with seven toes on 
its right foot. 
Polydactylus is not rare among animals that normally are possessed of 
several digits. In the human subject six or more fingers or toes are not 
very uncommon. In three well authenticated cases, as many as nine toes 
were developed on the left foot. iSSS. 
Correspondence. 
219 
There is already an extensive literature pertaining to teratology, and 
still it is desirable to have more accurate records of genuine cases of con- 
genital malformations, particularly such as may occur among non-domes- 
ticated animals and birds. There are many interesting questions, both 
scientific and popular, which may be enlightened by a powerful array of 
well attested facts. The miserable popular belief that maternal mental 
emotion can and does produce malformations, will receive its annihilat- 
ing blow when it is generally known that every form of malformation 
which has ever been observed in the human foetus, has its exact analogue 
in all the lower animals—viviparous and oviparous. It is a fact, that 
there is no physical monstrosity which is peculiar to the human foetus. 
George Jackson Fisher, M. D. 
Sing Sing, JV. T.