26 journal of Comparative Neurology and Psychology. 



lip group and have their innervation in common with that, and, 

 second, the fact that the buds on the mandible supplied by the 

 r;imus mand. ex. V appear ifirst on the anterior portions of the 

 mandible; that is, on the distal distribution of the nerves, and 

 later spread back to the posterior portion of the mandible at a 

 time corresponding to the appearance of buds in post-orbital and 

 opercular group. 



6. THE NASAL GROUP. 



A second group of taste buds isolated bv position and by 

 time of appearance includes those lying in front of the nasal 

 barblets, on the skin at the base of the nasal barblet, about 

 the nasal opening and those between the nasal barblet and the 

 eye. 



All these buds are innervated by the ramus oph. sup. V (Work- 

 man, 'go). This group can be broken down into four, or possibly 

 five, subdivisions separated by differences in position of the first 

 buds appearing and by a very slight difference in time of 

 appearance, although the group as a whole is quite homoge- 

 neous in both these respects. This group lies in the region 

 where the anterior and posterior nasal openings are formed, 

 and it is possible that the subdivisions in which this group 

 appears are due in some measure to the presence of this organ, 

 although at least three of them are indicated by divisions of 

 the nerves supplying them. 



The nasal opening is an antero-posterior slit still open through- 

 out its whole length in series L, but closed in series M. The for- 

 mation of two nasal openings from a single slit-like opening is 

 accomplished by the approximation of the dorsal and ventral lips 

 of the slit in the middle region, leaving an opening at either end 

 around which the nasal cones appear later. The nasal barblet 

 occupies a position slightly posterior to the middle of the dorsal 

 lip in the embryo but comes to have a more posterior position in 

 the adult quite near the posterior opening. 



The subdivisions of the group are as follows: 



(A) A group in front of the nasal barblet, on the top of the head, 

 and extending forward toward the snout and innervated by one of 

 the last four large divisions of the ramus oph. sup. V. 



(B) A group lying on the nasal barblet and innervated by the 

 remaining three of the last four divisions of the ramus oph. sup. V. 



