Ilia. lc. 



128 Ilia. lc. 



J. Das Material iiber die Zusammenarbeit der Keimblatter 



Versuche mit Grossdefekt an verschiedenen Regio- 



nen der Neurula — soil weiter bearbeitet werden. Triton 

 alpestris und TV. taeniatus. HSIAO-HUI CHUANG 



(dariibcr erschien bcreits eine vorlaufige Mitteilung in Z. Natur- 

 forschg. 2b. 1947) 

 T Determination in early development. Amphibians. 



P. CITTERIO 



Regulation. 

 H. The influence of Li on the primitive development of Illb. 2a. e. 

 the ascidian egg for analysing the potencies of regu- 

 lation in this "mosaic" egg. Ascidia malaca. 



P. D. NIEUWKOOP 



I. fitude de la polyembryonie chez les Poissons. Truite. 



G. STRUDEL 



J. fitudes relatives a la regulation d'un blastomere II isole. Nib. lc. 

 Triturus helveticus. A. DOLLANDER 



J. Regulation in blastula and gastrula stage. Urodela and 

 Anura. A. M. DALCQ in collaboration with coworkers 



}. Analysis of the regulative potencies of the invaginating Ilia. 7. 



archenteron roof and the induced neural plate along the 

 dorso-ventral and cranio-caudal axes in the amphibian 

 egg by heteroplastic transplantation of parts of the 

 dorsal blastoporal lip. Triturus alpestris, taeniatus and 

 cristatus. S. TOIVONEN and P. D. NIEUWKOOP 



J. Regulation potencies in the neural plate. Formation of Ilia. 7. 



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 tae~ 

 niatus, alpestris and cristatus. 



Miss M. BOUMAN, B. de PLANQUE 

 and P. D. NIEUWKOOP 



J. Ricerche su trapianti, espianti e parabiosi tra Anfibi 

 anuri e Urodeli alio scopo di indagare i processi di 

 regolazione, differenziazione nel quadro dei problemi 

 della costituzione biologica. 



G. COTRONEI, T. PERRI 

 and L. URBANI— MISTRUZZI 



J. Determination of: how entoderm regulates its lost parts, Ilia. 13. 

 when entoderm loses its power of regulation, and 

 whether the regulation power is lost gradually or sud- 

 denly at a certain stage. Moreover the question: 

 whether the entoderm at the neural plate stage still 

 retains its power of regulation when different portions 

 of entoderm are removed. Afterwards earlier stages will 

 be examined in similar way. Rana nigromaculata. 



Miss M. P. TSENG 



L. La polyembryonie et la monstruosite double experimen- Nib. lc. 

 tales chez les Oiseaux. H. LUTZ 



