174 
THE POULTRY BOOK. 
pressed bony off-growtb which rests on the frontal part of the head, is plainly 
solid, and has not the least connection with the cavity of the skull.” 
Blumenhach was evidently not intimately acquainted with this singular variety of 
fowls, as he makes several erroneous statements respecting their instincts and habits, 
and states that the abnormal formation is confined to the female sex. Some 
years since, the Editor, Mr. Tegetmeier, paid much attention to this very remark- 
able aberration, and, having made a large number of preparations of the crania 
of both sexes at different ages, read a paper on the subject before the members of 
the Zoological Society, which was illustrated hy engravings, and published in the 
Proceedings of the Society. 
The following cuts represent very faithfully this strange formation. The first 
figure shows the entire skull of a Golden- spangled Polish hen, the second that of a 
Silver-spangled Polish cock, which has been divided by a vertical longitudinal 
section : — 
rig, 1, Skull of a Ci’ested Hen, showing the spherical tuberosity supporting the crest 
and the deficiency of the intermaxillary bones supporting the nostrils. ’ 
Fig. 2. Section of the skull of a Crested Cock, showing the shape of the cavity 
containing the brain. 
By referring to these engravings, it will be seen that the tuberosity, which is 
situated on the fore part of the skull, is formed of bone, but that there are several 
apertures, which in the living animal are closed in by membrane. 
On looking at the section, it may be noticed that the anterior part of the brain 
is entirely contained in this tuberosity, so that this important organ is really of an 
hourglass shape. This peculiarity in its form does not, however, as Blumenhach 
