Morphological Studies. 775 



Gegenbaur (45, p. 15) and Emery (50, p. 590) regard this seg- 

 mentation into smell-buds as a secondary condition, which destroys 

 the value of any comparison with the sense organs of the lateral line, 

 and Emery adds (p. 592) that , although Madrid - Moreno's results 

 controvert Blaue's conclusions, „wird die Ansicht Beard's, dass das 

 Riechorgan der Reihe der „branchialen" Sinnesorgane gehöre, weder 

 bekräftigt noch erschüttert." 



I confess to a very different opinion. If the results of Madrid- 

 Moreno could justifiably be regarded as having the effect on Blaue's 

 conclusions, which Prof. Emery and his pupil think they have, then 

 not only would Blaue's conclusions go to the winds but 

 mine also. In reality, Madrid - Moreno's work has no sort of in- 

 fluence on the one or the other. 



It wasjust what one would expect from considerations 

 of the lateral line development that at first there would 

 be a piece of neuro-epithelium which would only later 

 on in development divide up more or less completely 

 into separate sense buds. The lateral line, as of 

 course Prof. Emery knows, also arises in this way, and 

 instead of producing evidence against Blaue's views or 

 mine. Prof. Emery and his pupil have, though to a very 

 slight extent, unwittingly helped our cause. Not that 

 my conclusions agree with Blaue's on all points — of that I have 

 already spoken in a former paper — but I agree fully with him in 

 regarding the smell-bud as the original condition of the nasal sense 

 organ, as the condition in which it was a branchial or lateral sense 

 organ whether a gill cleft was present or not. 



The argument employed by Prof. Gegenbaur (45) against the 

 primitive nature of the smell-bud is that the lower forms, i. e. the 

 Selachians and Physostomi, present an even olfactory epithelium in 

 which no division into sense buds has taken place. Here several 

 things are overlooked. Firstly it is tacitly assumed that the forms 

 with sense buds are derived from forms without them, i. e. from these 

 so called lower forms. Again it is assumed that the Selachians are 

 more primitive forms than other groups, i. e. Ganoidei. This latter 

 point is really an open question and a good deal can be said, and has 

 yet to be said, about the relationships of Selachians to other groups 

 of fishes. When one also remembers that smell-buds have been found 

 in Ganoids {Polypterus) it will be at once evident that the existence 

 of them in only certain groups of Teleostei does not affect the question 



