Perr 94 PI 



PERRI, T. Ricerche sull'indizione di arti soprannumerari mediante 

 trapianti di parti di ibridi o di embrioni irradiati con raggi X. Bufo 

 vulg., B. viridis and Rana esculents. Ilia. 2b. J. 



Ricerche su trapianti e espianti tra Anfibi anuri e urodeli alio scopo 



di indagare i processi di regolazione, differenziazione nel quadro 

 dei problemi della costituzione biologica. Ilia. lc. J. 



(in collaboration with G. COTRONEI) 



PERRY, J. H. Differentiation in the nervous system. Amblystoma. 



Ilia. 9. J. 



Vascular patterns in the developing nervous system. Homo sapiens. 



I. 15. M. 



PESONEN, S. The magnitudes of the pronuclei of fertilized ova. 



Albino mouse. I. 4. M. 



The parthenogenetic development of unfertilized ova induced by 



chemical stimulation. Albino rat. Ilia. 4. e. M. 



The effect of substituted acetic acids on the early ontogenetic 



development. Bufo and Rana (Anura) and Triturus (Utodela) . 



Ilia. 2a. e. J. 

 PETER, K. Das Leben des Keimlings, Aufsatze uber funktionelle Em- 



bryologie. Vertebraten. Ilia. lc. 



PFLEGER, Miss D. Recherches sur les hormones sexuelles embryon- 



naires. Oiseaux. Illb. 17. L. 



Role des acides nucleiques dans les phenomenes d'induction. Batra- 



ciens. Ilia. lc. J. 



PHILLIPS, R. J. S. Developmental study of a new fifth-toe Polydactyly 

 character in Mus musculus. IIIc. 3. M. 



PIATT, J. Transplantation of brachial cord segments in Amblystoma 

 punctatum embryos. With a view to analyzing the factors respon- 

 sible for normal cord structure and function; i.e. is continuity of 

 neural axis necessary for normal form and function of specific 

 parts? Ilia. 9. J. 



Survey of the motor regions of the brain of Amblystoma. With a 



view to a morphological and functional separation of each. I. 9. J. 



PIEPHO, H. Metamorphose der Insekt en. V. 2. D. 



PINCUS, G. (data not yet received). 



PIOTROWSKA, J. The influence of the short wave radiation on the 

 fertilization in Amphibia. Illb. 4. d. J 



PISANO', A. Development of isolated blastomeres of the Ascidian egg 



Ilia. 2b*. H 



Parabiosis between pure breed and hybrids Urodela. Triturus sps 



IIIc. 2. J 

 PLANQUE, B. de. Regulation potencies in the neural plate. Formation 

 of neural crest by regulation after implantation of young neural 

 plate tissue in the ventral side of neurulae, or by homogenetic 

 induction after implantation in middle gastrulae. (heteroplastic 

 transplantation). Triturus taeniatus, Tr. alpestris and Tr. cristatus. 



Ilia. lc. J. 

 (in collaboration with Miss M. BOUMAN and P. D. NIEUWKOOP) 



PLETZEN, R. van Ontogenesis of the breast-shoulder apparatus and 

 of the skeletogenous strata. Xenopus laevis. I. 11.}. 



