104 



Litte rat ur. 



1876. Grubee, W., Anatomische Notizen. Virchow's Archiv, Bd. 67, 

 p. 327—367. 



1877. Cunningham, D. J., Note on a connecting twing between the 

 anterior divisions of the first and the second dorsal nerves. The 

 Journal of Anatomy and Physiology, Vol. 11, p. 539 u. 540. 



187!». Furbringer, M., Zur Lehre von der Umbildung der Nerven- 

 plexus. Morph. Jahrb., Bd. 5, p. 324—394. 



1884. Davidoff, M., Ueber die Varietäten des Plexus lumbosacralis 

 von Salamandra maculosa. Morph. Jahrb., Bd. 9, p. 401 — 414. 



1892. Adolphi, H., Ueber Variationen der Spinalnerven und der Wirbel- 

 säule anurer Amphibien. I. Morph. Jahrb., Bd. 19, p. 313 — 375; 

 IL Bd. 22, 1895, p. 449—490; HI. Bd. 25, 1896, p. 115—142. 



1898. Adolphi, H., Ueber das Wandern der Extremitätenplexus und 

 des Sacrum bei Triton taeniatus. Morph. Jahrb., Bd. 25, p. 544 

 —554. 



Nachdruck verboten. 



On the Regeneration of Limbs in Frogs after the Extirpation of 



Limb-Rudiments. 



By Esther E. Byrnes. 



With 3 Figures. 



While studying the origin of limb-muscles in frogs and salaman- 

 ders , I accidentally injured and even wholly destroyed the limb- 

 rudiment of some of the embryos, in attempting to extirpate the 

 ventral halves of the myotomes in the limb-region. Subsequently 

 these embryos always developed limbs that were apparently normal. 

 I then 'made a series of experiments on extirpating only the limb- 

 rudiment of young embryos, without injuring the myotomes, and always 

 obtained the same results : i. e. the injured embryos always developed 

 perfect limbs. 



The constant presence of normal limb-rudiments in embryos from 

 which the limb-region had been presumably removed, could be inter- 

 preted to mean only one of two things: — Either the limb-rudiment 

 had not been wholly destroyed and had regenerated from cells already 

 in the limb-region, or it must have been wholly destroyed and sub- 

 sequently replaced by a limb formed out of new tissue that was 

 brought into the limb-region after the operation and during the pro- 

 cess of healing. 



I have repeated this experiment during several successive seasons 



