b Compensatory effect of multiple esterases owing to the action of null genes. Mus musculua 

 (Rodentia) 



• PORTER, K. R. Ph.D., Prof. — Biol. Labs.. Fac. of Arts and Sci.. Harvard Univ.. 16 



Divinity Ave., CAMBRIDGE, Mass. 02138, U.S.A. 

 a Elements of cell fine structure involved in determination of cell shape. 

 PORTMANN, A. Dr.Phil., Prof. (Emer.) — Zool. Anstalt der Univ., Rheinsprung 9, 4000 



BASEL, Schweiz 

 a Embryology. (Opisthobranchia, Prosobranchia, Gastropoda; Aves; Mammalia) 

 h Morphological analysis of early postembryonic development. (Rodentia; Insectivora) 

 PORTMANN, Miss A.-M. Lic.es Sci. — Lab. de Zool., Fac. des Sci. de Nancy, 30 Rue 



Ste Catherine, 54-NANCY, France 

 a Effet des rayons X sur la regeneration. Nereis diversicolor (Polychaeta errantia) 

 POTEMKINA, Mrs. D. A. Cand.biol.sci. — Dept. of Embryol., Fac. of Biol., Moscow Univ.. 



MOSCOW V-234, U.S.S.R. 

 POTTS, D. M. Ph.D. — Anat. School, Univ. of Cambridge, CAMBRIDGE, England 

 a Ultrastructure of implantation in normal animals and in experimental situations. Various 



spp. (Rodentia) 



• POULSON, D. F. Ph.D., Prof. — Dept. of Biol., Yale Univ., NEW HAVEN, Conn. 



06520, U.S.A. 

 a Mid-gut: genesis and differentiation. Drosophila melanogaster (Diptera) 

 h Chromosomal control of differentiation. Drosophila melanogaster (Diptera) 

 c Neurogenesis in normal and genetically deficient embryos. Drosophila melanogaster 



(Diptera) 

 d Maternally inherited sex-ratio disturbances of development. Drosophila melanogaster, D. 



bifasciata, D. willistoni, D. nebulosa (Diptera) 

 e Developmental genetics. Drosophila melanogaster (Diptera) 



POURHADI, R. M.D. — Lab. of Histol., Fac. of Med., B.P. 38, 63 CLERMONT-FER- 

 RAND, France 

 a Action of ultrasound on embryonic organisms. Triturus helveticus (Urodela) 

 b Histochemistry and ultrastructure of neonatal liver. Mus musculus (Rodentia) (in col- 

 laboration with P. MALET and J. P. TURCHINI) 

 POURREAU (SCHNEIDER). Mrs. N. M. Dr. — Lab. d'Embryol. exper. du Coll. de 



France et du C.N.R.S., 1 1 Place M. Berthelot, PARIS Ve, France 

 a Culture in vitro of adult chick organs as a medium for the proliferation of cancers 



from another species, 

 b In vitro studies on hematopoiesis in embryonic and adult spleen and bone marrow. 



(Aves; Mammalia) 

 c Use of organ culture and suspension culture techniques for the study of functional 



testicular interstitial cell tumors. Mus musculus, Rattus noruegicus (Rodentia) 

 POURTOIS, M. M.D., Lic.en Sci.dent. — Cleft Palate Research Center, Univ. of Pittsburgh, 



800 Salk Hall, PITTSBURGH, Pa. 15213, U.S.A. 

 PRAHLAD, K. V. Ph.D., Prof. — Dept. of Biol. Sci., Northern Illinois Univ., DeKALB, 111. 



60115, U.S.A. 

 a Study of induced metamorphosis: histological maturity and the development of tissue 



sensitivity to thyroid hormones in the embryo; biochemical changes evoked by thyroid 



hormones in embryonic and adult susceptible tissues. Ambystoma mexicanum, A. tigrinum, 



Necturus maculosus (Urodela) 

 b Comparative study of hypothalamo-pituitary-thyroid axis in pre- and post-metamorphic 



animals. Ambystoma mexicanum, A. tigrinum, Necturus maculosus (Urodela) 

 PRASAD, M. R. N. Ph.D., Prof. — Dept. of Zool., Univ. of Delhi, DELHI 7, India 

 PRASDNIKOV. E. Cand.med.sci. — Dept. of Embyol., Murmansky Sea-Biol. Inst., Acad, of 



Sci., DALNII ZELENZI, U.S.S.R. 

 a Immunity of embryo. Salmo salar (Teleostei) 



PRATT, C. W. McE. M.D. — Anat. School, Univ. of Cambridge, CAMBRIDGE. England 

 a Development of skeletal tissue. 

 PRAY, T. R. Ph.D., Prof. — Dept. of Biol., Univ. of Southern California, University Park, 



LOS ANGELES, Calif. 90007, U.S.A. 

 a Development of the gametophytes and juvenile stages of the sporophytes. (Cheilantheae, 



Pteridaceae) 

 b Development of the vein systems of leaves. Anemia spec, Marsilea spec, Cyrtomium spec. 



Acrostichum spec, and other spp. (Pterydophyta) 

 c Development of the dichotomous venation of the leaf. Ginko spec. 

 PREDA, V. M.D., Prof. — Cat. de Biol., Inst. Medico-Farmaceutic, Str. Pasteur 6, CLUJ, 



Rumania 

 a Influence de la temperature d'incubation sur I'infrastructure et I'immunomorphologie de 



I'embryon. Gallus spec. (Aves) 

 h Af frontation d'organes embryonnaires in vitro. Mus rattus (Rodentia) 

 PRESCOTT, D. M. Ph.D., Prof. — Inst, for Developm. Biol., Univ. of Colorado, BOULDER 



Colo. 80302, U.S.A. 



121 



