Lect. VII.] NASAL LABYRINTH OF THE TENREC. 1G9 



smell are distributed. These scrolls in us are divided 

 into the upper and middle turbinated bones ; in front and 

 below we have the maxillary or inferior turbinal, whose 

 nervous supply is from the first or ophthalmic Ijranch of 

 the fifth nerve — the trigeminal — the nerve wdiich sup- 

 plies most of the upper and lower face, and this first 

 branch is that nerve which sets up sneezing. Under the 

 median bar or thick base of the septum nasi or 

 partition wall of the nose-passages, we have a vomer or 

 j)loughshare bone, large and long in proportion to 

 the great intertrabecular beam which it undersplices. 

 There are also other little vomers, two in front protect- 

 ing Jacobson's organs, and two behind, tying the legs of 

 the main vomer to the turbinal masses, as in the Hedge- 

 hog. But that which, to me, is wholly unique, and 

 morphologically inexplicable, at present, is the subdivi- 

 sion, by su]3erficial peeling, of the main or middle 

 vomer. 



I have examined vomers of all sorts and sizes, in types 

 varying from a Sturgeon to a Man ; but this harking, as 

 it may be called, of the median piece is to me something 

 new. In the nearly ripe embryo of the Tenrec the bone is 

 relatively very large, and is becoming rough, cracked, and 

 cellular; but in young from the nest, about the size of 

 Field Mice, the lower surface of the bone has sj^lit itself, 

 like the bark of the plane-tree, into secondary fiakes. 

 There are two of these superficial centres of ossification, 

 one before the other, and they sheath the inner and main 



