330 
POPULAK SCIENCE KEYIEW. 
The teeth of Rotif era. — The Rev. Lord Sidney Godolphin Osborne made a 
communication on this subject to the Literary and Philosophical Society of 
Manchester at its meeting on April 6 . The dental organ, he says, con- 
sists primarily of two slightly arcuate jaws, broad at their upper extremi- 
ties and narrow and pointed at their lower ones. Elastic ligaments bind 
these together at each end. The front or convex margin of each jaw is 
crenulated, the projections corresponding with the transverse parallel ridges 
usuall}^ regarded as the teeth of the animal. These jaws form the two lips 
of a sac, the lateral parts of which consist of a separate tissue, which over- 
laps each jaw at its anterior margin, hooked on, as it were, to the crenulations 
and thrown by them into permanent parallel corrugations. Each of these 
corrugated organs passes first outwards and then downwards and backwards, 
where they are bound together by another broad membrane, which completes 
the sac posteriorly. The food enters this sac by a passage from the oesopha- 
gus, at its superior extremity, is crushed between the two jaws, and then 
passes out again by a similar orifice at its opposite or lower end to enter the 
stomach. Of these tissues the jaws are the hardest, and are capable of being 
dissected out, as Lord S. G. Osborne has succeeded in doing. The lateral 
coiTugated organs have a concavo-convex form, which they appear capable 
of retaining after dissection 5 they appear less dense than the jaws, but more 
so than the membranous tissues of the gizzard, to which they are united. 
The central corrugations are always the largest. 
The Varieties of Dogs. — Dr. John Edward Gray has written a paper on 
the varieties of dogs in the Annals of Natural History. In reference to 
that kind of variation, which he thinks ought to be looked upon as abnor- 
mality, the author points out the following four types : — 1. The short and 
more or less bandy legs of the turnspit and lurchers, which are common to 
terriers and spaniels. 2. The more or less imperfect development of the 
upper jaw, found in the bull-dog, pug-dog, and different breeds of spaniels. 
3. The great development of the ball of the eyes, so as to become too large 
for the orbit and exceedingly prominent and liable to accident, found in 
some breeds of spaniels and terriers. 4. The more or less complete want 
of hair, which is generally accompanied by a more or less complete want or 
great imperfection in the development and rooting of the teeth, showing 
the relation between these two organic productions. 
The Conformation of the Negro Cranium. — At the meeting of the Physical 
Society of Edinburgh, on April 7, a paper was communicated by Dr. J. S. 
Smith and Professor Turner, on eight negro crania, recently sent from Old 
Calabar. Four of tlie skulls were those of males and four females. They 
were the crania of slaves of the Calabar negroes, and were probably of the 
Iboe tribe, having been brought from the delta of the mighty Niger or 
(^uorra. These negroes have been described as being among the most 
degraded of the negro race. The skulls, however, showed no such appear- 
ance of degra^lation, and one of the male skulls had an internal capacity or 
brain bulk of 1 >.‘» cubic inches. The crania also exhibited a much greater 
variety of size than was to have been expected in a rude negro people. Mr. 
Ilobb considers that the degraded state of the delta negi'oes has been much 
exaggerated. He has lived among them, and states that they are simply 
what paganism makes them, but their nature is similar to our own, and they 
