1866.) Biology. 545 
germinal spots, which are readily examined in very young ova, as 
consisting of a material resembling protoplasm only in its great 
instability and tendency to vacuolate. The action of water and 
other agents on the tissues of the ovum was carefully discussed. 
The observation of the dotted structure of the yelk sac has led 
Dr. Ransom to ascertain that it does not grow by the apposition 
of either internal or external layers, but by interstitial development. 
In studying such structures it is very necessary to use a suitable 
medium. Dr. Ransom recommends a mixture of glycerine and 
water, which can readily be brought to the right density. 
Dr. W. Turner, of Edinburgh, described the very curious 
method of gestation in a new fish, belonging to the genus Arius, 
which he had received from Ceylon. The female fish deposits her 
eggs, which are then taken into the mouth of the male, who swims 
about with them until they hatch. Dr. Turner's correspondent 
had been very careful to avoid any mistake or imposition in the 
matter. The fish lived in stagnant pools in marshy ground, where 
they were caught in large numbers by the natives. Dr. Ginther, 
of the British Museum, said it was very remarkable that m South 
America there was a fish almost exactly like that which Dr. 
Turner had described, and Agassiz had lately described several 
others from the Amazons possessing this curious method of gesta- 
tion ; none, however, had been observed in Africa. Fishes of the 
most distant regions were often most alike, as, for example, certain 
species found in Madeira and in Japan. 
Dr. Cobbold read one of his horrifying papers “On the Entozoa 
of the Dog in Relation to Public Health,” in which he showed that 
Trichina might be communicated by the dog to man. 
Mr. Groom Napier brought forward papers “On the Food and 
Economic Value of British Butterflies and Moths,” and, “On the 
Causes of Variation in the Eggs of British Birds.” 
Mr, Frank Buckland amused the Section, as is his custom, by a 
jocose description of Salmon and Oyster fisheries. 
In Human Anatomy there was but one paper, but that was 
of considerable interest, being “On Variations in the great Arterial 
Blood Vessels,” by Dr. G. D. Gibb. The author illustrated the 
subject by two examples. In the first, the large vessel rismg from 
the heart, called the aorta, gave four branches instead of the usual 
three, the right carotid and the subclavian, both rising by a distinct 
and separate trunk, there being necessarily an absence of the in- 
nominate artery. In this curious case there was an irregularity in 
the division of both femoral arteries and in the left sciatic nerve. 
In the second example, the aorta divided into two great branches ; 
the first of which subdivided into the usual innominate and the left 
