374 NOTICES OF THE MEETINGS, [Feb. 10, 1854. 
The homologous teeth being thus determinable, they may be’ 
severally signified by a symbol as well as by a name. The in- 
cisors, e. g., by their initial letter 7., and individually by an added 
number, i. 1, i. 2, and i, 3; the canines by the letter c.; the pre- 
molars by the letter p.; and the molars by the letter m.; these 
also being differentiated by added numerals. Thus, the number 
of these teeth, on each side of both jaws, in any given species, 
Man e. g., may be expressed by the following brief formula :— 
a: — c. = D. — m. —. == 32; and the homologies 
of the individual teeth, in relation to the typical formula, may be 
signified by i. 1., 1.2.3 c.; p.3., p.4.3 m.1.,m. 2.,m.8,: the 
suppressed teeth being i. 3., p. 1., and p. 2. 
These symbols are so plain and simple as to form no obstacle to 
the ready comprehension of the facts explained by means of them. 
Were those facts described in the ordinary way, by means of the 
verbal phrases or definitions of the teeth ; as for example, in Man, 
‘the second deciduous molar, representing the fourth deciduous 
molar in the typical dentition,” instead of d. 4, and so on, the de- 
scriptions of the manifold modifications of the teeth and of dental 
development must continue to occupy much unnecessary space, 
and levy such a tax upon the attention and memory, as would in- 
evitably tend to enfeeble the judgment and impair the power of 
seizing and appreciating the results of the comparison.* 
Each year’s experience had strengthened the Lecturer’s con- 
viction that the rapid and successful progress of the knowledge 
of animal structures, and of the generalizations deducible there- 
from, would be mainly influenced by the determination of the 
homology of parts and organs, and by the concomitant power of 
condensing the propositions relating to them, and attaching to 
them signs or symbols, equivalent to their single substantive 
names. In the Lecturer’s work on the “ Archetype of the 
Skeleton,” he had denoted most of the bones by simple numerals ; 
the symbols of the teeth are fewer in number, are easily under- 
stood and remembered ; and, if generally adopted, might take the 
place of names: they would, then, render unnecessary the endless 
repetition of the verbal definition of the part, harmonise conflicting 
synonyms, serve as a universal language, and at the same time 
express the expositor’s meaning in the fewest and clearest terms. 
The Entomologist had long found the advantage of such signs as 
é and @¢, in reference to the sexes of Insects and the like; and 
the Anatomist would find it to his advantage to avail himself of 
this powerful instrument of thought, instruction, and discovery, 
from which the Chemist, the Astronomer, and the Geometrician 
have obtained such important results. [R. O.] 
