a Temporal and spatial patterns of cell replication and nuclear degeneration during lens 



development and growth; computer analysis of mathematical models. Gallus domestictis 



(Aves) (in collaboration with S. P. MODAK) 

 URBAN, P. Ph.D. — Dept. of Biol. Sci., Union College, SCHENECTADY, N.Y. 12308. 



U.S.A. 

 a Fine structure of gametogenesis, fertilization and early development. Bryopsis hypnoides 



(Chlorophyceae) 

 URBANI, E. Prof. — 1st. di Istol. ed Embriol., Univ. di Roma, Fac. di Sci., Citta Univer- 



sitaria, 00185 ROMA, Italy • 



a Cytochemical and autoradiographic investigations on oogenesis. Dytiscus marginalis 



(Coleopfera) 

 URBANI (MISTRUZZI), Mrs. L. Prof.Inc. — 1st. di Istol. ed Embriol., Fac. di Sci., Univ. 



di Roma, Citta Universitaria, 00185 ROMA, Italy 

 URSPRUNG, H. Ph.D., Prof. — Lab. for Developm. Biol., Swiss Federal Inst, of Technol., 



Sonneggstr., ZURICH, Switzerland • 



a Biochemical studies on differentiation. Drosophila nielanogaster (Diptera), Rana pipiens, 



Xenopus laevis (Artura), Mus musculus (Rodentia), Gallus domesticus (Aves) 

 h Organization of imaginal discs. Drosophila melanogaster (Diptera) 

 c Ultrastructure and enzymology of fertilization. Ascidia nigra (Tunicata) 

 UYSAL, M. M.D. — Inst, of Histol. and Embryol., Med. Fac, Hacettepe Sci. Center, 



ANKARA, Turkey 

 a Collagenogenesis in the umbilical cord. Homo sapiens (Primates) 

 VAAGE, S. M.D. — Anat. Inst., Univ. of Oslo, Karl Johansgatan 47, OSLO, Norway 

 VACEK, Z. MUDr., D.Sc, Prof. — Inst, of Embryol., Fac. of Med., Charles Univ., Alber- 



tov 4, PRAGUE 2, Czechoslovakia 

 a Electron microscopy and histochemistry of the placenta (comparative studies on the sub- 

 microscopic structure, enzyme histochemistry and transport mechanism). Homo sapiens 



(Primates), (Rodentia; Carnivora; Insectivora; Chiroptera) 

 b Role of primitive streak and tail region in early differentiation of the body (submicro- 



scopic and cytochemical studies in normal and experimental conditions). Rana esculenta 



(Anura), Gallus domesticus (Aves), Mus ratfus (Rodentia) 

 VAHS, W. Dr.phil., Prof. — Zool. Inst, der Univ., Weyertal 119, 5 KOLN-Lindenthal, W. 



Germany 

 a Quantitative cytochemistry of nucleic acids and proteins during induction and differen- 

 tiation. (Teleostei; Urodela; Aves) 

 h Phase specific gene activities in the different germ layers and in the eyecup-lens-system 



of the developing embryo, as revealed by quantitative cytochemical DNA determinations. 



Salmo irideus (Teleostei), (Urodela) 

 c Biochemistry of early development including yolk utilization. (Teleostei; Amphibia) 

 VAKAET, L. C. A. M.D., Prof. — Lab. of Anat. and Embryol., State Univ. Center, Groe- 



nenborgerlaan 171, ANTWERPEN, Belgium • 



a Early development. Gallus domesticus (Aves) 



h Fetal and neonatal endocrinology. Mus musculus albinus (Rodentia) 

 VALDEZ de MORENO, Mrs. C. L. — Inst, de Biol., Univ. Nac. de Tucuman, Chacabuco 



460, S. M. de TUCUMAN, Argentina 

 a Respiration studies on spermatozoa. Bu^o arenarum (Anura) 

 VANABLE, J. W., Jr. Ph.D. — Dept. of Biol. Sci., Purdue Univ., LAFAYETTE, Ind. 



47907, U.S.A. 



temporarily: Dept. of Biol., Yale Univ., Kline Biol. Tower, NEW HAVEN, Conn. 06520, 



U.S.A. 

 a Thyroxin control of skin gland development: the origin of the gland rudiments; the control 



of the decision to produce mucous or granular secretion. Xenopus laevis (Anura) 

 VAN ALTEN, P. J. Ph.D., Prof. — Dept. of Anat., Coll. of Med., Univ. of Illinois, 1853 



W. Polk St., CHICAGO, 111. 60612, U.S.A. 

 a Ontogeny of the immunological mechanism. Gallus domesticus (Aves) 

 h Development of lymphocyte competence to respond to mitogens in vitro. Gallus 



domesticus (Aves), Rattus norvegicus (Rodentia) 

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



59 rue de Namur, LOUVAIN, Belgium • 



VANDERHAEGHE (HOUGARDY), Mrs. F. Dr.en Sci. — address unknown 

 VAN DETH. J. H. M. G. M.D. — Dept. of Anat. and Histol., Univ. of Adelaide, ADE- 

 LAIDE, S.Australia 5000, Australia 

 a Teratogenesis by hormones. Gallus domesticus (Aves), Rattus norvegicus (Rodentia) 

 h Hormonal influences on sex determination. Gallus domesticus (Aves) 

 VAN GANSEN (RASMONT), Mrs. P. Agrege — Lab. de Morphol. Anim., Univ. libre de 



Bruxelles, 67, rue des Chevaux, RHODE-ST-GENESE, Brabant, Belgium 

 a Descriptive and experimental morphology of nucleoli, ribosomes and glycogen during 



maturation, fertilization, segmentation and early gastrulation (electron microscope studies). 



Xenopus laevis (Anura) 



178 



