474 Mr. S. Hatta. Mesodermic Origin and the Fate of the 



is the descendant of the somites. In short, the branehiomery and mesomery 

 are independent of each other. 



The cartilaginous visceral arches and their equivalents in the primordial 

 skull are branchiomeric organs, and have no genetic relation to the mesomeres. 



Therefore, it seems extremely probable that the participation of the 

 sclerotomes in the branchial elements and in their equivalents, which is 

 maintained by Koltzoff, Schalk, and others, is, if such actually occurs, nothing 

 but accidental. 



I wish to express my warmest thanks to Prof. MacBride, of the Imperial 

 College of Science, London, and to Dr. Gadow, Prof. Gardiner, Mr. Doncaster, 

 and Prof. Punnett, of Cambridge University, for the courtesy which they 

 showed me during my stay in Cambridge, and especially in according to me 

 the privilege of working there. 



LITERATURE. 



80. Balfour, F., " A Treatise on Comparative Embryology/' London, 1880-1881. 



04. Brauer, A., " Beitrage zur Kenntnis der Entwicklung und Anatomie der Gymno- 



phionen. IV. — Die Entwicklung der beiden Trigeminusganglien : ' ' Zool. Jahr., 



Suppl. Bd. 7. 



02. Dohrn, A., " Studien zur Urgesckichte des Wirbeltierkorpers. XXII. — Weitere 

 Beitrage zur Beurteilung der Occipitalregion und der Ganglienleiste der Selachier," 

 'Mitteil. Zool. Stat. Neapel.,' vol. 15. 



06. Gaup, E., " Die Entwicklung des Kopfskelettes," ' Hertwig's Handb. vergl. exper. 



Entw.-leb.re d. Wirbelt.,' vol. 3. 



90. Goette, A., " Entwicklungsgescbicbte des Flussneunauge (Petrornyzon Jluviatilis)" 



' Abb. entw. gescb. d. Tiere,' Part 5. 



91. Hatta, S., " On tbe Formation of Germinal Layers in Petrornyzon," ' Journ. Coll. Sci. 



Imp. Univ. Tokyo,' vol. 5. 



92. " Contributions to tbe Morpbology of Cyclostomata. I. — On tbe Formation of 



tbe Heart in Petrornyzon," Ibid., vol. 8. 



97. "Preliminary Note on tbe Development of tbe Pronephros in Petrornyzon," 



1 Ann. Zool. Jap.,' vol. 1 . 



00. " Contributions to tbe Morphology of Cyclostomata. II. On tbe Development 



of the Pronephros and Segmental Duct in Petrornyzon," 'Journ. Coll. Sci. Imp. 

 Univ. Tokyo,' vol. 13. 



01. "On the Relation of the Metameric Segmentation of Mesoblast in Petrornyzon 



to that in Amphioxus and in the Higher Crauiota," ' Ann. Zool. Jap.,' vol. 5. 



07. " Bemerkungen iiber die friiheren Entwicklungsstudien des Gefassystems bei 



Ammocoeten," ' Journ. Agric. Coll., Imp. Univ., Sapporo,' vol. 4. 



14a. "Ueber die Entwicklung des Gefassystems beim Neunauge {Lampetra 



mitsukv.rii, Hatta)." 



146. "Die Bildung.sweise und die erste Differenzierung des Mesoderms beim 



Neunauge {Lampetra mitsukurii, Hatta)." 

 14. Keiser, W., " Untersuchungen iiber die erste Anlage des Herzens, der beiden 



Langsstamme und des Blutes bei Embryonen von Petrornyzon planeri" 'Jen. 



Zeitschr. Natur.,' vol. 51. 



