s evidently much larger than in the Cochin skull of the
same size, and extends much further beyond the interorbital septum, but
laterally is less deep. Whether this cavity is entirely filled by the
brain, may be doubted. In the skull of the Cochin and of all ordinary
fowls a strong internal ridge of bone separates the anterior from the
central cavity; but this ridge is entirely absent in the Polish skull
here figured. The shape of the central cavity is circular in the
Polish, and lengthened in the Cochin skull. The shape of the posterior
cavity, together with the position, size, and number of the pores for
the nerves, differ much in these two skulls. A pit deeply penetrating
the occipital bone of the Cochin is entirely absent in this Polish
skull, whilst in another specimen it was well developed. In this second
specimen the whole internal surface of the posterior cavity likewise
differs to a certain extent in shape. I made sections of two other
skulls,--namely, of a Polish fowl with the protuberance singularly
little developed, and of a Sultan in which it was a little more
developed; and when these two skulls were placed between the two above
figured (fig. 35), a perfect gradation in the configuration of each
part of the internal surface could be traced. In the Polish skull, with
a small protuberance, the ridge between the anterior and middle
cavities was present, but low; and in the Sultan this ridge was
replaced by a narrow furrow standing on a broad raised eminence.

[Illustration: Fig. 35.--Longitudinal sections of Skull, of natural
size, viewed laterally. A. Polish Cock. B. Cochin Cock, selected for
comparison with the above from being of nearly the same size.]

{264}

It may naturally be asked whether these remarkable modifications in the
form of the brain affect the intellect of Polish fowls; some writers
have stated that they are extremely stupid, but Bechstein and Mr.
Tegetmeier have shown that this is by no means generally the case.
Nevertheless Bechstein[429] states that he had a Polish hen which "was
crazy, and anxiously wandered about all day long." A hen in my
possession was solitary in her habits, and was often so absorbed in
reverie that she could be touched; she was also deficient in the most
singular manner in the faculty of finding her way, so that, if she
straye