TRANSACTIONS OF THE SECTIONS. 117 
ally the result of exposure to cold, are produced by trifling alterations in the quantity 
or quality of this secretion, which, when very abundant, is known to cause nearly 
complete mcapacity of hearing, until the accumulation be removed. In this respect 
the ear seems to possess an analogy with the other organs of sense, the skin, the 
tongue, the nose, and the eye, in all of which the normal condition of the surface 
secretions is necessary for the due performance of the specific function of the organ. 
Dr. Carlile also called attention to the form of the external ear in some species of the 
Vespertilionide, more especially in the Plecotus auritus. In this animal the external 
ear consists of a large posterior auricle, almost as long as the body of the creature, 
and a small anterior auricle, nearly symmetrical with the larger, the tube of the ear 
Opening at the lower part of these appendages, in front of the larger, and behind the 
smaller. The smaller auricle is generally regarded as an operculum, which prevents 
the entrance, into the tube of the ear, of the air, when the animal flies with rapidity 
in pursuit of its prey or against the wind; but more probably, like the tragus, its 
homologue in the human ear, it serves as a reflector, receiving on its back or inner 
surface many rays of sound, sent by reflexion from the front or hollow surface of 
the larger auricle, and reflecting them again to the same surface, whence they are 
transmitted, either by one reflexion or by several, between the opposed surfaces of 
the large and small auricles, to the tube of the ear, in order to reach the membrana 
pani. Were it not for this provision, many rays of sound, after a first reflexion 
from the surface of the larger auricle, would pass into the air, and be altogether lost. 
The large size of the cochlea in some Vespertilionidz, found in connexion with the 
great expansion of the auricle, would seem adverse to the opinion that the cochlea is 
the portion of the internal ear specially adapted to receive sounds conveyed by con- 
duction through the solid parts of the head, the great reflecting power of the auricles 
being one of the distinguishing characteristics of the organ. 
A “Register of Periodical Phenomena at South Lincolnshire,” and “ Register of 
Periodical Phenomena at Llangefelach, Glamorganshire,” were presented. 
GEOGRAPHY AND ETHNOLOGY. 
On the Ethnological and Physical Characters of the Negro variety of man- 
kind. By Antoine D’Axspanie, Correspondent of the French Institute. 
Tue following statements were founded chiefly on the author’s own observations 
collected during a ten years’ stay in Eastern Ethiopia. 
The settlement of the negroes in Africa was effected by a stream of immigration 
flowing from east to west. The negro tribes who live now in the most easterly parts 
have the largest facial angle, the greatest amount of intelligence, and can be referred, 
by slow and almost imperceptible gradations of form and colour, to the red races of 
Ethiopia, which all authors have until now agreed in referring to the Caucasian 
stock. From his total inability to decide whether several individuals of the 
Doggo, Barya, and Nara tribes belonged to red or to negro origin, he has been forced 
to conclude that all future controversies on the creation of negro varieties of man- 
kind must take into account the fact of a gradual formation of the black variety, or 
at least must explain, in the uncalled-for hypothesis of a separate negro creation, 
how tribes living in continual war with their neighbours, have amongst themselves, 
and spontaneously as it would seem, several individuals who must be referred to a 
variety alike alien to the majority of their relations and to that of their fellow- 
countrymen. ) 
_ The author proceeded to quote several facts drawn from tribes living at opposite 
extremities of Ethiopia and separated by an extent of country equal to the breadth 
of France. It is inferred from these facts, that in tropical Africa the skin of man 
is blackened when the chief food is not animal, but vegetable. Numerous direct 
observations prove that the air of Ethiopia differs from that of Europe by some very 
