4 THE AMPHIOXUS. 



by Max Schultze, 1 some by Leuckart and Pagen- 

 stecher, 2 on the later stages of the larvae. And in 

 these, too, in view of the incompleteness of the inves- 

 tigation, there was no real understanding of these 

 stages, nor was there shown any real knowledge of 

 the development of the embryo, or of the transition 

 to the fully developed animal. AVe may say that 

 our knowledge of the larvse was scarcely helped 

 at all by Max Schultze. But we should not forget 

 that through the writings of Leuckart and Pagen- 

 stecher a more intimate acquaintance was obtained 

 with the remarkable want of symmetry of the larvae, 

 as well as with many other details, whose im- 

 portance was first explained by Kowalevsky. The 

 latter 's explanation was however only partial, and 

 there is now still need of further information on the 

 matter. 



Kowalevsky's first statements on the subject are to 

 be found in a little-known and unimportant pamphlet, 

 published in Russian, in 1865. This was afterwards 



1 Zeitsclir.f. Wtss. Zoologic, 1852, pag. 416. 



2 R. Leuckart imd Alex. Pagenstecher : " Untersuclmngen 

 ilber niedere Seetliiere, Amphioxus lanceolatus," Arch.f. Anat. 

 und Phys., lierausgegeben von J. Miiller, 1858, pag. 558-569. 



