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or less completely, of no less than 55 different forms of Echinoderms, 

 the development of which was totally unknown till now. The present 

 contribution accordingly represents a very considerable addition to our 

 knowledge of the development and the larval forms of Echinoderms and 

 — combined with our previous knowledge — forms a reasonable founda- 

 tion for a discussion of the problem that was the main object of these 

 researches: the interrelation between the larvae and the adults in regard 

 to a natural classification. Also the comparative study of pelagic larvse 

 of unknown parentage, especially of the Ophiurid larvae, yields valuable 

 support for the conclusions to be drawn. Of course, very much more 

 needs to be done. The investigations here recorded may only be regarded 

 as an introduction. Still, enough is done already to give us a glimpse 

 of the end; it is evident that the way here entered upon is the right way, 

 which will lead to the desired results. I hope to be able in the future 

 to carry these researches further towards a definite solution of the problem. 



