Landacre, Taste Buds of Ameiuriis. 



35 



It is possible that the irregularity of these two groups can be 

 explained by the fact that they lie in close proximity to the post- 

 orbital group which is large and appears much earlier. The 

 functional needs of this portion of the body being thus well sup- 

 plied, these two groups are not of so much importance as the 

 body buds which occupy the regions back of the operculum alone. 

 However, the innervation of the region under discussion is com- 

 plicated and very difficult to work out, according to Professor Her- 

 RiCK, so that there may be some facts about the innervation which 

 would clear up the difficulty, and there is a slight possibility that 

 we may have to deal with nothing more than an individual varia- 

 tion, since only one series of each embryo has been catalogued. 



The limits of the body group were determined with reference 

 to the lateral line organs and to the free posterior border of the 

 operculum; that is, the point at which it was detached from the 

 body dorsally in the section. 



TABLE X. 



Table showing the number and position of the buds on the body with reference to the organs of the 

 main lateral line of the body, the free posterior border of the operculum and the distance in sections from 

 the posterior buds of the opercular group. 



The first body buds lie in each series between the third and 

 fourth main lateral line organs. The lateral line organs seem 

 to be constant in position with reference to each other and to 

 the posterior free border of the operculum, so that in locating 

 these buds by the organs we avoid difficulties arising from the 

 irregular growth of the head as compared with the rest of the body 

 which might arise if they were located by sections alone. 



Of the four buds found in the 17^ mm. embryo, two are found 

 between lateral line organs three and four, as are the two found 

 in each of the earlier series of the 11 mm. and 14! mm. and 

 the other two are found behind the fourth lateral line organ. 



