176 GEORGE L. STREETER 



icle. If gravity were the controlling factor all of the ear vesicles 

 in larvae removed from their membranes would be obliquely 

 placed, whether operated upon or not. This we know does 

 not occur, and therefore we may safely assume that gravity does 

 not exercise any great influence on the posture of the ear vesicle. 



LITERATURE CITED 



Eycleshymer, a. C. 1907 The closing of wounds in larval Necturus. Amer. 

 Jour. Anat., vol. 7. 



Harrison, R. G. 1903 Experimentelle Untersuchungen liber die Entwicklung 

 der Sinnesorgane der Seitenlinie bei den Amphibien. Arch. f. mikr. 

 Anat., Bd. 63. 



1910 The outgrowth of the nerve fiber as a mode of protoplasmic move- 

 ment. Jour. Exp. ZooL, vol. 9. 



Hertw'ig, O. 1899 Ueber einige durch Centrifugalkraft in der Entwicklung des 

 Froscheies hervorgeruf ene Veranderungen. Arch, f . Mikr. Anat., Bd. 53 



Kappers, C. U. a. 1908 Weitere Mitteilungen ueber Neurobiotaxis. Folia 

 Neuro-Biologica, Bd. 1. 



Lewis, W. H. 1907 On the origin and differentiation of the otic vesicle in am- 

 phibian embryos. Anat. Rec, vol. 1. (Amer. Jour. Anat., vol. 7). 



Spemann, H. 1906 a tJber eine neue Methode der embryonalen Transplantation. 

 Verh. d. Deutsch. Zool. Gesell., 



1906 b tJber embryonale Transplantation. Verh. d. Gesell. Deutsch. 

 Naturf. u. Arzte, 78 Vers., Stuttgart. 1910. Die entwicklung des 

 invertierten Horgriibchens zum Labyrinth. Arch. f. Entwick.-Mech., 

 Bd. 30. 



Streeter, G. L. 1906 Some experiments in the developing ear vesicle of the 

 tadpole with relation to equilibration. Jour. Exp. Zool., vol. 3. 



1907 Some factors in the development of the amphibian ear vesicle, and 

 further e.xperiments on equilibration. Jour. E.xp. Zool., vol. 4. 



1908 Nuclei of origin of the cranial nerves in the 10 mm. human embryo. 

 Anat. Rec, vol. 2. 



1909 Experimental observations on the development of the amphibian 

 ear vesicle. Anat. Rec, vol. 3. 



Wetzel, G. 1904 Zentrifugierversuche an unbefruchteten Eiern von Rana fusca. 

 Arch. f. mikr. Anat. u. Entwick., Bd. 63. 



