On the Vomer in Man and the Mammalia. 95 
The vomer and sphenoidal sponge/ bones in man. — Having 
found the vomer and lateral masses of the ethmoid so univer- 
sally connected, we naturally inquire how they are related in 
man. They are not in contact. Their only connection is 
that the expanded portion of the vomer which grasps the 
rostrum lies beneath the sphenoidal spongy bones, and that 
these articulate with the lateral masses of the ethmoid. Now, 
seeing that the sphenoidal spongy bones are recognised as 
ossifications distinct from the sphenoid, I think we have 
already sufficient evidence to prove that they represent the 
ethmo-vomerine laminae, by aid of what we have noticed in 
the Chimpanzee's skull ; for it is impossible to doubt either 
that the distinct bone which lies between the orbital plates of 
the ethmoid and the vomer in that skull corresponds to the 
ethmo-vomerine lamina of other monkeys ; or, on the other 
hand, that it corresponds to the sphenoidal spongy bone in 
man. But the correspondence becomes much more distinct 
when we study the early condition of the sphenoidal spongy 
bones. The most interesting condition of these bones is when, 
in the skulls of young children, they can be got completely 
ossified and not yet destroyed by amalgamation with the 
neighbouring bones. In this state the sphenoidal spongy 
bone is somewhat of the shape of a hollow pyramid with the 
apex directed backwards, its inner aspect parallel to its fellow, 
and its cavity (the first form of the sphenoidal sinus) opening 
at its base into the nasal cavity in front (fig. 2). This pyramid 
is constructed by the union of at least three distinct pieces of 
bone. Firstly, there is an orbital piece, forming a portion of 
the wall of the orbit between the ethmoid and sphenoid, an 
element, I believe, in the formation of the orbital wall not 
hitherto observed. It articulates with the orbital process of 
the palate bone, and, together with the inferior piece, com- 
pletes the nasal foramen of the palate-bone, namely, the fora- 
men called spheno-palatine, but which we have seen to be 
invariably ethmo-palatine in other animals. The superior 
piece bounds the sphenoidal sinus above and on the inside, 
and ultimately becomes incorporated with the sphenoid bone. 
The inferior piece is the largest of the three ; it forms the 
floor of the sphenoidal sinus, and the under half of its opening 
