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145 
tension, conduction, and collection of sound. Subsequently a 
peculiar arrangement of structure is added with a spevial nerve 
supply that is adapted to appreciate more delicate characters in the 
composition of sound demanded by the increasing variations in 
vocal utterances connected with the extension, form, and develop- 
ment of the animal kingdom. A third addition, yet further, takes 
place, in adaptation to a change of medium in which the animal 
lives, as the hitherto more aquatic becomes mixed with the terres- 
trial and aerial, or confined to the two latter, and also in accordance 
with the progressive development and variations of the vocal 
power of other creatures. In the first change the simple otocyst is 
enlarged into the vestibule or vestibular sac with its divisions, 
called the utriculus and sacculus ; to the former are added curved 
channels termed the Labyrinth. These changes in several of their 
variations were demonstrated in detail, and shown to occur mainly 
in fishes. The gradual advance of such alterations was particularly 
dwelt upon, as well as the gentle gradations, by which the transi- 
tion from one class to another is made. In the next group, 
Reptilia, the advance, incident to the mixed life, on land and in 
water, or simply terrestrial, was shown by the gradual formation 
from the sacculus of the vestibule, of that peculiar arrangement for 
the appreciation of the more delicate character of tones in sound, 
to which the name Cochlea is applied. The commencing develop- 
ment of the third addition, the formation of an air chamber, with 
extended communications, fitted with an exposed membrane stretched 
across an external orifice, and brought into relation with the 
vestibule by a column (columella) of bone, the whole arrangement 
entitled the tympanum, was pointed out. Lastly, the great advances 
in all these additions, the greater finish in the structure, and the 
fuller adaptation thereby to the increasing demands for appreciation 
of tones in sound were shown in the group aves. 
XXXI.—On Time, as a Geological Factor.—By A. 8. Rem, M.A., 
G8. 
roth JANUARY, 1888. 
The author pointed out the proneness to speculative theories 
exhibited in the childhood of the individual, of a nation, of a 
science; the question ‘‘Why’’? always preceding the question 
“What” ? He showed how a misconception of the part played 
by Time accounted for early geological errors. Taking an example, 
he pointed out how an erroneous idea of the age of the world had 
prevented, for a long time, any doctrine of uniformity being 
tenable. He then showed how an inability to grasp the immensity 
of geological time, as contrasted with historical periods, tended to 
the production of speculative theories to account for the apparent 
‘‘crowding” of events. Another liability to error lay in the 
