364 
NATURE 
e 
[ Sepé. 7, 1871 

spirit and enthusiasm displayed throughout proved how 
greatly the value of the course was appreciated. When it 
is remembered that, with scarcely an exception, these 
teachers had hitherto never used the microscope, never 
dissected a single organ or organism for themselves. nor 
seen one properly dissected, the advantage gained by the 
experience they have now obtained, even if only a portion 
of what was condensed into six weeks’ work remains with 
them, is something very considerable, for it is something 
of a zew kind, a form of knowledge which they had en- 
tirely failed to obtain before. 
It is exceedingly interesting to find that no difficulty 
was experienced in going over all these matters in a class 
which was not confined to men alone, and most heartily 
do we hope to see in the future a larger proportion of 
women engaged in this and other branches of scientific 
study. Those whoimagine that women have some innate 
incapacity, and assert that if admitted to classes now 
limited to men they would be unable to profit by them, or 
would hinder the progress of the class by the greater atten- 
tion they would require in order to keep them to the level 
of male students, may take this fact to heart—one of the 
microscopes offered asa prize for the best work done, and 
the best record of the lectures and the day’s work, was 
adjudged simply upon the merits of her reports and work 
to the one lady among the thirty-nine students who formed 
the class. On the other hand, this fact will probably 
stimulate that unavowed feeling, akin to the trades-unions’ 
hostility to competition, which is the cause of the arbitrary 
exclusion of one half of the community from our greatest 
educational institutions. E.R. 


MAGNUS’S BONES OF THE HEAD OF BIRDS 
Untersuchungen tiber den Bau des Knochernen Vogel- 
kopfes. Von Dr. Hugo Magnus, Assistentarzt an der 
Klinik des Herren Prof. Dr. Forster, zu Breslau. Mit 
sechs Tafeln. (Leipzig: Engelmann, 1870; pp. 108. 
London : Williams and Norgate.) 
‘ala work is a systematic description of the form, 
structure, and relations of the various bones of the 
head of birds. Each bone is taken separately, and the 
cuief varieties it presents in the several sub-classes are 
described, and are illustrated by carefully drawn plates. 
In here giving a brief notice of the work, we need 
scarcely say that the details of the several bones in the 
adult state are very well and clearly given, and the author 
has had opportunities, of which he appears to have 
thoroughly availed himself, of studying and comparing 
the skulls of a large number of birds. The mode in 
which the variations from typical structure are given is 
instructive and accurate. We willgivean extract to show 
the mode in which he deals with the subject, and select a 
part of his account of the squama of the Temporal :— 
“The squama of the Temporal Bone (Squama, 
Sheitelbein, Geoffroy) closely resembles that of Mammals 
in its form and position, It is an elongated, scale-like 
bone situated upon the lateral wall of the skull above the 
tympanic cavity, and is posteriorly in contact with the 
occipital,above with the parietal or temporal, and anteriorly 
with the great wing of the sphenoid, with which, as we 
have already seen, it frequently unites to form the posterior 
orbital process. The external convex surface of the squama 
for the most part enters into the formation, sometimes more 
and sometimes less, of the temporal fossa, especially in 
the long-billed marsh and aquatic birds. From the pro- 
cessus orbitalis posterior a semicircular line runs upon or 
around the squama, separating it with its striz or ribs 
from the planum temporale. Near the anterior border of 
the squama,and usually below the posterior orbital process, 
a process shoots forth from its surface, which is the 
Processus Zygomaticus of Carus and the temporal pro- 
cess of KGstlin. This in some birds, as in the Larks, 
Parrots, and Fowls, is tolerably well marked, and fuses 
with the processus orbitalis posterior. In the singing 
birds, this process is very variable in size; in Thrushes, 
Sylviadz, Motacillidee, and Hirundinide, it is rather 
feebly developed, resembling a small blunt head. Inthe 
Fringillidee it is developed into a slender rod, as it is also 
in Edolius, and (though to a less degree) in Lanius. In 
the Paridz it forms a broad lamina. In the Corvini, 
it is considerably developed; while in the Falcons it 
appears to be entirely absent. In Owls it is slender and 
acicular. Inthe Woodpeckers it is very large, and occu- 
pies a special groove of the Quadrate bone. Inthe marsh 
and aquatic birds it approximates very closely to the 
articular surface of the 03 quadratum, and is for the most 
part of very small size.” He then proceeds to describe 
the internal surface of the squama, and its junction with 
other bones to form the tympanic cavity. 
The principal defects of the book are obviously that the 
author has little acquaintance with the history of the em- 
bryological development of the class of birds generally, and 
does not appear to have studied the serial homologies of 
the several bones in other classes. 
As an instance of the former defect, we may note that 
Herr Magnus maintains with Nitzsch that the os 
dentale, or median portion of the lower jaw, is de- 
veloped from a single point of ossification. “I have 
never,” he says, “been able to discover the presence of 
two nuclei, even in the youngest animals I have examined, 
nor any trace of a suture.” We would refer to Mr. Parker’s 
paper on the head of the fowl, as clearly showing the 
double nature of this bone, though no doubt the two parts 
early coalesce. Taking the ethmoid bone again, we find 
Dr. Magnus describing it rightly as a cranial bone, or 
rather as one belonging to his animal sphere. He notices 
the singular modification in form it undergoes throughout 
the whole class, and observes that it is a thin bony plate 
lying between and in front of the globes of the eye. The 
anterior portion, he goes on to say, situated in front of the 
eyes, and provided with lateral processes that shut off the 
nasal from the orbital cavities, may be regarded as the 
labyrinth of the ethmoid. And then comes the remark- 
able statement that ‘the plate extending backwards from 
this and separating the two orbital plates from each other 
is the crésta gal/i, whilst the short plate extending for- 
wards into the cavum narium represents the lamina per- 
pendicularis.” This scarcely appears to us to be an 
accurate representation. The crista galli is to all intents 
and purposes an intracranial projection of bone, we mizht 
even consider it to be a portion of the falx cerebri which 
has undergone ossification, and such result must be above 
the plane of the canals for the nasal branch of the 
fifth ; in point of fact, it may be seen in all birds ina 
rudimentary form between the two passages for the olfac- 
tory nerves, (See note to Mr. Parker's paper * On the 
structure of the Skull of the Common Fowl,” Phil. Trans. 
1869, p. 762.) The septum between the two orbits is chiefly 
and not to a small extent only, formed by the os perpen- 

