a. Development of the sympatho-adrenal system. (Amphibia; Aves; Mam- 

 malia) 



b. Cytological indices of cell differentiation in the nerve tube of early em- 

 bryos. (Amphibia; Aves) 



c. Study of neuro-humoral regulation of melanogenesis. (Mammalia) 

 SMRECZYNSKI. S. Ph.D. — Zool. Dept. of the Jagiellonian Univ., sw. 



Anny 6, KRAKOW, Poland 



(no embryological work in progress) 

 SNELLEN, H. A. Med.Dr., Prof . — Dept. of Cardiol., Fac. of Med., Acad. 



Ziekenhuis, LEIDEN, Netherlands 

 a. Heart and vessels in congenital malformations. Homo sapiens (Primates) 



(in collaboration with J. DANKMEIJER, Miss A. DEKKER and Miss 



H. C. van INGEN) 

 SOLERE, Dr. en Med. — Lab. d'Embryol., Fac. de Med., 45 Rue des Sts. 



Peres, PARIS Vie, France 

 a. Developpement normal et anormal de l'appareil digestif. Mus rattus (Ro~ 



dentia) , Homo sapiens (Primates) 

 SOROKIN, S. P. A.B., M.D. — Dept. of Anat., Harvard Med. School, 25 



Shattuck St., BOSTON 15, Mass., U.S.A. 

 a. Histochemistry and electron microscopy of organ cultures. Gallus domestic 



cus (Aves), Cavia cobaya, Rattus norvegicus (Rodentia) 

 SPIEGEL, M. B.S., Ph.D. — Dept. of Zool., Dartmouth Coll., HANOVER, 



N.H., U.S.A. 



a. Protein changes in development. Arbacia punctulata (Echinoidea), Rana 

 pipiens (Anura) 



b. Role of enzyme induction in development. Rana pipiens (Anura) 



SPIRITO A. Dott., M.I.I. E., Prof. — 1st. di Biol, gen., Fondazione Agraria, 



S. Pietro, PERUGIA, Italia 

 a. Origine e natura dei tumori. Bufo spec. (Anura) 



SPISAK (PLONKA), Mrs. I. M.Sc — Dept. of Biol, and Embryol., Acad, 

 of Med., ul. Kopernika 7, KRAKOW, Poland 

 a. Experimental induction of immunological tolerance in embryos and adult 

 animals. Transfer of immunological tolerance to F 1 generation. Mesocri- 

 cetus auratus, Mus musculus, Rattus spec. (Rodentia) (in collaboration 

 with Mrs. A. SKOWRON (CENDRZAK) and J. ZABInSKI) 



SPOFFORD, W. R. Ph.D., Prof. — Dept. of Anat., School of Med., State 

 Univ. of New York, 766 Irving Ave., SYRACUSE 10, N.Y., U.S.A. 



a. Induction and determination in the neural plate. Ambystoma maculatum 

 (Urodela) 



b. Experimental neurogenesis. Ambystoma maculatum (Urodela) 

 SPRATT, N. T., Jr. A.B., Ph.D., F.I.I.E., Prof. — Dept. of Zool., Coll. of 



Sci., Lit. and Arts, Univ. of Minnesota, MINNEAPOLIS 14, Minn., 

 U.S.A. 



a. Investigating the nutrient requirements essential to morphogenesis and 

 growth in the early stages of development (pre-streak and streak blasto- 

 derms). Gallus domesticus (Aves) 



b. Survey of dehydrogenase enzymes in early embryos. Gallus domesticus 

 (Aves) 



1. Localization of enzyme activity. 



2. Structural integrity and enzyme activity. 



131 



