Vand 91 Vann 



VANDEBROEK, G. Dr Sc, Prof. — Lab. d'Embryol.. Inst, de Zool., Univ. 

 de Louvain, 71, Rue de Namur, LOUVAIN, Belgique. 



a. Morphogenetic movements during the gastrulation of Ascidia aspersa 

 and Styela partita. (Ascidians) 



b. The mechanics of gastrulation in Ascidia aspersa and Styela partita. 

 (Ascidians) 



c. Protoplasmic movements after fertilization of Ascidia aspersa. (Ascidians) 



d. The organization of Ascidian embryos studied by the influence of cen- 

 trifugation; a. action on isolated parts; b. local action of centrifugation. 

 (recombination after centrifugation) 



e. Induction and competence phenomena during the development of 

 Ascidia aspersa. (Ascidians) 



f. Action of LiCl and NaSCN on the development of Ascidia aspersa and 

 Styela partita. (Ascidians) 



g. Development of the neural system of Balanoglossus kowalewskii. (En- 

 tetopneusta) (in collaboration with J. JANSSENS) 



h. Morphogenetic movements during gastrulation of Coelenterata, Enterop- 



neusta and lower Chordates. 

 i. The general comparative, descriptive and experimental embryology of 



the Merazoa and their classification. The place of the Cycloneuria (Echi- 



nodermata. Enter opneusta, Pterobranchia and Chaetognatha) in the 



animal Kingdom, 

 j. The development of the trabeculae cranii in perch embryos from which 



the prosencephalon has been removed. Perca (Osteichthyes) 

 k. The development of the trabeculae cranii in perch embryos treated with 



LiCl. Perca (Osteichthyes) (in collaboration with M. T. CLAES) 

 1. Modifications of the competence in Triturus taeniatus after local action 



of LiCl. (Utodeles) (in collaboration with E. BONE) 

 m. Study of the factors of morphogenesis in the embryo of Saccoglossus 



kowalewskii. The potencies of ectoblast isolated at the beginning of 



gastrulation. (Enteropneusta) 

 n. The distribution of nucleic acids during the development of Eisenia 



foetida (Annelida), Saccoglossus kowalewskii (Enteropneusta) and 



Ascidia aspersa (Tunicata). (in collaboration with coworkers) 

 VANNINI, E. Dr, Lib. doc. — 1st. di Zool. e Anat. comp., Fac. di Sci., 



Via Loredan 6, PADOVA, Italia. __ 



a. Cycle of the nucleic acids during ovogenesis. (Fishes and Amphibia) 



b. Development and differentiation of the gonads, with special reference 

 to embryological relations between the medullary tissue of the gonads 

 and the cortico-adrenal blastema. (Amphibia, Birds and Mammals) 



c. Experimental actions of the steroid hormones (testosterone, oestradiol, 

 progesterone, desoxycorticosterone on the sexual differentiation, with 

 analysis of their stimulative or inhibiting effects on the development of 

 the cortical or medullary tissues of the gonads. (Amphibia and Birds) 



d. Experimental regeneration and asexual multiplication (schizogenesis) in 

 a hermaphrodite Polychaete, Salmacina incrustans (Clap.), with special 

 reference to the origin and the sexualisation of the germ-cells. 



e. Experimental analysis of the causal development of the gonad in Uro- 

 deles. Triturus alpestris and taeniatus (Started at the Hubrecht Labora- 

 tory, Utrecht, Holland) 



