_905_ 



Now after three years I have learnt a lesson from Dr. Eisig, and I 

 must admit I prefer with him the term „lateral sense organs"; though 

 I still believe the organs are special branchial sense organs in the 

 Ichthyopsida. 



Prof. Froriep further remarks that had I known that those sense 

 organs typically belonged to the gill clefts 1 should have greeted 

 Marshall's view as supporting my own. 



unlike Blaue, who has practically taken up this double po- 

 sition, I cannot also hold the gill nature of the nose, and could 

 only accept Marshall's results as far as the segmental nature of the 

 olfactory nerve was concerned. Prof. Froriep moreover overlooks the 

 fact that until my researches were published, in which I described 

 the early development of the lateral sense organs of Elasmobranchs 

 in connection with epiblastic fusions of the different cranial ganglia, 

 there was nothing to shew that his socalled sense organs had any 

 existence outside the Mammalia. In other words, it was a brilliant 

 hypothesis on his part that they were rudiments of sense organs, and 

 hence stood in relationship to the gill clefts. 



In his monograph of the Capitellidae Dr. Eisig recognizes that 

 I was the first to apply the doctrine of branchial sense organs to ac- 

 tually existing sense organs — those of the lateral line. If the actual 

 development in Ichthyopsida were still unknown, the branchial sensory 

 nature of Prof. Froriep's Anlagen would be also still hypothetical. 

 VAN Wijhe's researches, fruitful as they were in regard to the somites 

 and nerves, were far from complete as regards the sense organs in 

 connection with the nerves — a circumstance which Prof, Froriep 

 recognized in his paper „Über Anlagen von Sinnesorganen etc." (p. 36 

 — 40). In those pages there is a long discussion of the homology of his 

 „Anlagen" with structures in Selachians as described by van Wijhe, 

 and especially with the „ Seitenorgan - Anlagen "^ and the conclusion 

 is arrived at that the homology is „keine ganz strenge". 



For my part I don't know what sort of homology this is if it 

 is „keine ganz strenge". Either the homology is complete, or it is 

 in this case no homology at all. It turned out as the result of my 

 researches that the homology is complete and correct. 



In conclusion, so far as I am concerned Prof. Froriep is welcome 

 to that priority to which he is really entitled. At the same time I 

 must again insist that my discovery of this relationship of sense or- 

 gans to gill clefts was, though made and published after Prof. Fro- 

 riep's discoveries of the rudiments of the sense organs in Mammalia, 

 perfectly independent of it. 



