of the wild Boar , and Animal incognitum. 321 
there are, properly speaking, only four grinders, forming a 
regular row. 
As the jaw increases in length, a small cell is formed in its 
substance, behind the last grinder, in which the rudiments of a 
new tooth appear: these increase, along with the cavity in 
which they are contained ; and the new tooth is in every respect 
larger than the preceding one. By the time it is completely 
formed, and ready to cut the gum, the jaw has extended itself, 
so that there is room for it to come into its place, as the poste- 
rior grinder. 
While this tooth is concealed in the jaw, another cell is 
formed immediately beyond it ; and there is a small round hole 
of communication between the two cells, similar to what is met 
with in the elephant ; but there are no remains of such a com- 
munication, between the anterior cell and the socket of the full 
grown tooth immediately before it. 
The last mentioned cell is at first very small ; but gradually 
increases to a prodigious size; and the tooth formed in it is 
nearly double the size of the preceding large grinder. Its mas- 
ticating surface has a row of four projections on each side, and 
the tooth has eight fangs ; so that it very much resembles two 
large grinding teeth incorporated into one : the posterior fangs 
are not completely formed at seven years of age. 
This large tooth, although it is formed in the posterior part 
of the jaw, is brought sufficiently forward, by the growth of the 
jaw bone, to cut the gum, and range in the line with the other 
teeth, making the connected row of grinders six in number. 
From its very great size, it not only fills the jaw completely, 
but all the bodies of the other five teeth are pushed by it out of 
their perpendicular direction, leaning a little forwards. 
mdcccl T t 
