PROTOZOA AND INVERTEBRATE EGGS 331 



Tchakotine, S. (I*t35a) La parthenogenese artificial do I'ooiif do la pholado par 



micropuncture ultraviolotte. Compt. rend. soc. biol., 119: 1394-1396. 

 (1935b) Sur Ic iiiocanisme de la roaction do la couche superficielle do I'ofMif 



de la pholade a Im inioropunrturr ultraviolptto. Compt. roiid. soc. bio!., 120: 



714-716. 

 — (1935c) Floculation localisee des coUoides dans la cellule par la micropuncture 



ultraviolette. Compt. rend., 200: 2036-2038. 



(1936) Effets d'irradiation locali.see du noyaux des infusoires par micro- 



puncture ultraviolette. Compt. rend., 202: 778-781. 

 Tennent, D. H. (1942) The photodynamic action of dyes on the eggs of the sea 



urchin, Lytechinus variegatus. Carnegie Inst. Wash. Publ., Papers from Tortugas 



Lab., 35: 1-153. 

 Waxier, S. H. (1941) Immunization against cecal coccidiosis in chickens by the use 



of X ray attenuated oocysts. J. Am. Vet. Med. Assoc, 99: 481-485. 

 Wells, P. H., and A. C. Giese (1950) Photoreactivation of ultraviolet light injury in 



gametes of the sea urchin Strongylocentrotus purpuratus. Biol. Bull., 99: 163-172. 

 Wels, P. (1938) Beobachtungen am bestrahlten Zellkern. Naunyn-Schmiedeberg's 



Arch, exptl. Pathol. Pharmakol., 189: 113-139. 

 Wichterman, R. (1947) Action of X rays on mating types and conjugation of Para- 

 mecium bursaria. Biol. Bull., 93: 201. 



(1948a) The biological effect of X rays on mating types and conjugation of 



Paramecium bursaria. Biol. Bull., 94: 113-127. 



(1948b) Mating types and conjugation of four different races of Paramecium 



calkinsi and the effects of X rays on the mating reaction. Biol. Bull., 95: 271- 

 272. 



(1953) The biology of Paramecium. Blakiston Company, New York. 



Wilbur, K. M. (1939) The relation of the magnesium ion to ultraviolet stimulation 

 in the A' ems egg. Physiol. Zool., 12: 102-109. 



Wilbur, K. M., and R. O. Recknegel (1943) The radiosensitivity of eggs of Arbacin 

 punctulata in various salt solutions. Biol. Bull., 85: 193-200. 



Wottge, K. (1939) Fortgesetzte Beobachtungen am bestrahlen Zellkern. Nauyn- 

 Schmiedeberg's Arch, exptl. Pathol. Pharmakol., 193: 96-106. 



Wright, W. H., and E. D. McAlister (1934) The effect of ultraviolet radiation on the 

 ova of the ascarid roundworms Toxocara canis and Toxascaris leonina. Smith- 

 sonian Misc. Coll., 93: 1-13. 



Wyss, O., F. Haas, J. B. Clark, and W. S. Stone (1950) Some effects of ultraviolet ir- 

 radiation on microorganisms. J. Cellular Comp. Physiol., 35, Suppl. 1: 133-140. 



Yamashita, H., K. Mori, and M. Miwa (1939) The action of ionizing rays on sea 

 urchins. II. The effects of roentgen, gamma, and beta rays upon fertilized eggs. 

 Gann, 33: 117-121. 



(1940) The action of ionizing rays on sea urchins. V. The mitotic observa- 

 tions on the effects of roentgen rays upon the unfertilized eggs and sperm. 

 Gann, 34: 239-245. 



Zain, H., and A. Wolf (1943) Einfluss der Rontgenstrahlen auf die Entwicklung der 

 Endothelstadien der Vogelmalaria {Plasmodium gallinaceum). Deut. Tropen- 

 med. Z., 47: 68-71. 



Zhalkovsky, B. G. (1938) On the difference of biological action of transmitted and 

 reflected visible light. I. Experiments with Paramecia caudata. Bull. biol. 

 med. exptl. U.R.S.S., 5: 493-495. (Not seen. Abstract in Ber. wiss. Biol., 50: 

 171 seen.) 



Zirkle, R. E. (1936) Modifications of radiosensitivity by means of readily pene- 

 trating acids and bases. Am. J. Roentgenol. Radium Therapy, 35: 230-237. 



Manuscript received by the editor, Xov. 29, 1950 



