
References
The principal papers on Colpoda, Tillina and Woodruffia are given in the references Papers published in the last century are not included, except for Schulz (1899). They are referred to by Goodey (1911). Less important papers of the present century not referred to in the text are not included.
Adolph, E. F., 1929. The regulation of adult body size in the protozoan Colpoda. J. Exp. Zool., 53, 269–311.
Barker, H. A. and Taylor, C. V., 1931. A study of the conditions of encystment of Colpoda cucullus. Physiol. Zool., 4, 620–634
" 1933. Studies on the excystment of Colpoda cucullus. Ibid., 6. 127–136.

Beers, O. D.,1943. The maintenance of vitality in pure lines of the ciliate Tillina magna Amer. Nat., 78, 68–76.
" 1945. Some factors affecting excystment in the ciliate Tillina magna. Physiol. Zool., 18, 80–99.
" 1946. History of the nuclei of Tillina magna during division and encystment. J. Morph., 78, 181–200.
Bodine, J. H., 1923. Excystment of Colpoda cucullus. J. Exp. Zool., 37, 115–125.
Bridgeman, A. J., 1948. Studies on some aspects of cystment in Tillina magna. J. Exp. Zool., 108, 21–44.
Brown, M. G. and Taylor. C. V., 1938. The kinetics of excystment in Colpoda duodenaria. J. Gen. Physiol., 21, 475–500.
Brown, M. G., 1939. The blocking of excystment reactions of Colpoda duodenaria by absence of oxygen. Biol. Bull, 77, 382–390.
Burt, R. L., 1940. Specific analysis of the genus Colpoda with special reference to the standardisation of experimental material. Trans. Amer. Micr. Soc., 59, 414–432
Burt, R. L., Kidder, C. W. and Glaff, C. L., 1941. Nucleau reorganization in the family Colpodidae. J. Morph, 69, 537–552
Burt, R. I. 1945. Narcosis and cell division in Colpoda steinii. Biol. Bull. 88, 12–29
Chang, H. T. and Loomis, W. E., 1945. Effect of carbon dioxide on absorption of water and nutmentsi by roots. Plant. Physiol., 20, 220–232
Clatton, E. and Tellier, L., 1927a. Sur les hmites de resistance de quelques Infusoires d'ean douce aux solutions de chlorures. C. R. Soc. Biol., 97, 285–288.
—— 1927b. Sur les limites et les vitesses de retour a l'equilibre physiologique du Glaucoma pyriforims porte dans les solutions hypeitoniques de NaCl. Ibid. 97. 780–784.
Darby, H. H., 1929. The effect of the hydrogen-ion concentration on the sequence of protozoan forms. Arch. Protistenl, 65, 1–37.
Dawson, J. and Hewitt, D. C, 1931. Longevity of encysted Colpoda. Amcr. Nat., 65. 181–186.
Demianov, E. A., 1943. An infusorian of the genus Colpoda found in a child suffering from haemocolitis. Med. Parasitol., 12, 60–64.
Doflein, F., 1928. Lehrbuch der Protozoenkunde. Jena.
Enriques, P., 1907. La conjugazione e il differenziamento seesuale negh infusori Arch. Protistenk. 9. 195–296.
—— 1908. Sulla morfologia e sistematica del genere Colpoda. Arch. Zool. Exp. Gen. Ser. 4, 8, i-xv.
Finley, H. E., 1930. Toleration of fresh water protozoa to increased salmity. Ecology, 11, 337–347.
Fisher, K. C. and Stern J. R., 1942. The separation of an “activity” metabolism from the total respiration of yeast by the effects of ethyl carbamate. J. Cell. Comp. Physiol., 19, 109–122.
Garnjobst, L., Tatum, E. L., and Taylor. C. V. 1943. Further studies on the nutritional requirements of Colpoda duodenaria J. Cell. Comp. Physiol., 21, 199–212.
Garnjobst, L., 1947. The effect of ceitain deficient media on resting cyst formation in Colpoda duodenaria Physiol. Zool., 20. 5–14.
Goodey, T., 1911. A contribution to our knowledge of the protozoa of the soil. Proc. Roy. Soc. London, B, 84, 80–102.
—— 1913. The exeystment of Colpoda cullus from its resting cysts and the nature and properties of the cyst membrane. Ibid. 86, 427–439.
Greig. Smith, R., 1912. Contubutions to our knowledge of soil fertility. Proc. Linn. Soc. N. S. W, 37, 655
Haagen-Smit, A. J. and Thimann. K. V., 1938. The excystment of Colpoda cullus. I. The chemical nature of the existing factors in hay infusion. J. Cell. Comp. Physiol., 11, 389–407.
Hoare, C. A. 1927. Studies on coprozoieeiuliates. Parasilology, 19. 154–222.
Hughes, A. F. W., 1950. The effect of inhibitory substances on cell division. Quart. J. Micr. Sci., 91. 251–278.
—— 1952 Some effects of abnormal tomerty on dividing cells in chich tissue cultures. Ibid, 93, 207–219.
Jacobs, M. H. 1912. Studies on the physiological characters of species. I. The effects of carbon dioxide on various protozoa J. Exp. Zool. 2, 519–542.
—— 1922. The effects of carbon dioxide on the consistency of protoplasm. Biol. Bull., 42., 14–30.

Jennings, H. S. and Moore, E. M., 1901. Studies on reactions to stimuli in unicellular organisms. VIII. On the reactions of Infusoria to carbonic and other acids with especial reference to the causes of gatherings spontaneously formed, Amer. J. Physiol, 6, 233–250.
Jennings, H. S., 1915. Behaviour of the Lower Organisms. Columbia University Press, New York, 366 pp.
Johnson, W. H. and Larson, E., 1938. Studies on the morphology and life history of Woodruffia metaboica n.sp. Arch. Protistenk., 90, 383–392.
Johnson, W. H. and Evans, F. R., 1939. A study of encystment in the ciliate, Woodruffia metabolica. Arch. Protistenk., 92, 91–116.
" 1940. Environmental factors affecting cystment in Woodruffia metabolica. Physiol. Zool., 13, 102–121.
" 1941a. A further study of environmental factois affecting cystment in Woodruffia metabolica. Ibid, 14, 227–237.
" 1941b. Dedifferentiation and redifferentiation of cilia in cysts of Woodruffia metabolica. Trans. Amer. Micr. Soc., 60, 7–16.
Kavanau, J. L., 1950. Enzyme kinetics and the rate of biological processes. J. Gen. Physiol., 34, 193–209.
Kidder, G. W. and Claff, C. L., 1938. Cytological investigations of Colpoda cucullus. Biol. Bull., 74, 178–197.
Kidder, G. W. and Stuart, C. A., 1939a. Growth studies on ciliates. I. The role of bacteria in the growth and reproduction of Colpoda. Physiol. Zool., 12, 329–340.
" 1939b. Growth studies on ciliates. II. The food factor in the growth, reproduction and encystment of Colpoda. Ibid, 12, 341–347.
Kitching, J. A., 1939. The effects of lack of oxygen and of low tensions on Paramecium. Biol. Bull., 77, 339–353.
Koffman, M., 1924. Uber die Bedeutung der Wasserstoffionenkonzentration fur die Encystrerung bei emigen Ciliatenaiten. Arch. f. Micr. Anat., 103, 168–181.
Loefer, J. B., 1939. Acclimatization of fresh-water ciliates and flagellates to media of higher osmotic pressure. Physiol. Zool. 12, 161–172
Mcelroy, W. D, 1947. The mechanism of inhibition of cellular activity by narcotics. Quart. Rev. Biol., 22, 25–58.
Mcintyre, R. A., 1949. Length of application of the excystment-inducing stimulus in relation to percentage of excystment in Tillina magna. J. Elisha Mitchell Sci. Soc., 65, 123–130.
Medawar, P. B., 1947. The behaviour of mammalian skin epithelium under strictly anaerobic conditions. Quart. J. Micr. Sci., 88, 27–37.
Needham, J., 1942. Biochemistry and Morphogenesis. Cambridge University Press.
Noland, L. E, 1925. Factors influencing the distribution of fresh water ciliates. Ecology, 6, 437–452.
Oddo, A. M. and Esposito, M., 1951. Changes in the potassium content of sea urchin eggs on fertilization. J. Gen. Physiol., 34, 285–294.
Pace, D. M. and Ireland, R. L., 1945. The effects of oxygen, carbon dioxide and pressure on growth in Chilomonas paramecium and Tetrahymena geleii Furgason. Ibid, 28, 547–557
Pack, D. A., 1919. Two ciliates of Great Salt Lake. Biol. Bull, 36, 273–282.
Padnos, M., Jakowska, S., and Nigrelli, R. F., 1951. Studies on Colpoda. I. Some new observations on the life cycle. Proc. Amer. Soc. Protozool., 2, 3–4.
" 1953a. Studies on Colpoda. II. The morphology and cytology of aged corrugated resting cysts of Colpoda. maupasi (Bensonhurst Strain) kept in cultures up to four years. Ibid, 4, 18.
" 1953b. Studies on Colpoda. III. Effects of low temperature on reproductive cysts of Colpoda maupasi (Bensonhurst Strain). Ibid. 4. 18.
Penn, A. B. K., 1937. Reproduction in Colpoda cucullus. Arch. Protistenk., 88, 366–373.
Phelps, A., 1947. Growth of protozoa in pure culture. III. Effect of temperature on the division rate J. Exp. Zool, 102, 277–292.
Prater, A. N. and Haagen-Smit, A. J. 1940. The excystment of protozoa. Isolation of crystalline excystment factors for Colpoda duodenaria. J. Cell. Comp. Physiol, 15, 95–101.

Reynold, B. D., 1936. Colpoda steinii, a facultative parasite of the land slug, Agriolimax agrestis. J. Parasitology, 22, 48–53.
Richards, O. W., 1941. The growth of protozoa. Protozoa in Biological Research, ed. Calkins and Summers. Columbia University Press.
Root,W. S, 1930. The influence of carbon dioxide upon the oxygen consumption of Paramecium and the eggs of Arbacia. Biol. Bull., 59, 1–47.
Schiilz,", 1899. Colpoda cucullus im Darm des Menschen. Berl. klin. Wschr., 36, 353.
Seifriz, W., ed, 1942. The Structure of Protoplasm. Iowa State College Press, Ames, Iowa.
Singh, B. N., 1941. The influence of different bacterial food supplies on the rate of reproduction in Colpoda steinii, and the factors influencing encystment. Ann. Appl. Biol, 28, 65–73.
Strickland, A. G. R, 1940. The effect of concentration of Colpoda duodenaria on the time required for encystment in food-free medium. Physiol. Zool., 48, 245–301.
Strickland, A. G. R. and Haagen-Smit, A. J., 1947. Chemical substances inducing excystment of the resting cysts of Colpoda duodenaria. J. Cell. Comp. Physiol., 30, 381–390.
" 1948. The excystment of Colpoda duodenaria. Science, 107, 204–205.
Stuart, C. A, Kidder, G. W, and Griffin. A. M, 1939. Growth studies on criliates. III Experimental alteration of the method of reproduction in Colpoda. Physiol. Zool., 12, 348–362.
Tatum, E L., Garnjobst, L, and Taylor, C. V., 1942. Vitamin requirements of Colpoda duodenaria. J. Cell. Comp. Physiol., 20, 211–224.
Taylor, C. V. and Strickland, A. G. R., 1936. Effects of high vacua and extreme temperatures on cysts of Colpoda cucullus Physiol. Zool, 9, 15–26.
Taylor, C. V., Brown, M. G., and Strickland, A G. R., 1936. Effects of a given X-ray dose on cysts of Colpoda sternii at successive stages of their induced excystment. J. Cell Comp. Physiol, 9, 105–116.
Taylor, C. V. and Strickland, A. G. R., 1938. Reactions of Colpoda duodenaria to environmental factors. I. Some factors influencing growth and encystment. Arch. Prolistenk., 90, 396–409.
" 1939. Reactions of Colpoda duodenaria to environmental factors. II. Factors influencing the formation of resting cysts. Physiol. Zool., 12, 219–230.
Taylor, C. V., and Garnjobst, L., 1939. Reorganization of the “Silverline System” in the re productive cysts of Colpoda duodenaria. Arch. Protislenk., 92, 73–90.
Taylor, C. V., and VAN Wagtendonk, W. J, 1941a. Growth studies of Colpoda duodenaria. I. Sterilization of the ciliates. Physiol. Zool., 14, 431–436.
" 1941b. Growth studies of Colpoda duodenaria in the absence of other living organisms. J. Cell. Comp. Physiol. 17, 34.
Thimann, K. V., and Barker, II. A. 1934. Studies on the excystment of Colpoda cucullus. II. The action of the excystment inducing substance. J. Exp. Zool., 69, 37–57.
Thimann, K. V., and Haagen-Smit, A J., 1937. Effects of salt on emergence from the cyst in protozoa. Nature. 140, 645.
Thimann, K. V. and Commoner, B, 1940. A differential volumeter for micro-respiration measurements. J. Gen. Physiol, 23, 333–341.
Thomas, J. O., 1942. The Anaerobic Carbohydrate Metabolism of Tetrahymena geleii. Dissertation, Stanford University.
Wagtedonk, W. J. Van, and Taylor, C. V. 1942. The nature of the plasmoptyzate growth factoi foi Colpoda duodenaria. J. Cell. Comp. Physiol, 19, 95–101.
Watson, J. M, 1944. Studies on the morphology and bionomics of a little known holotrichous cilihate—Balantiophouminutus. II. The effect of environmental factors. J. Roy. Micr. Soc, 64, 31–67.
" 1946. The bionomics of coprophilic protozoa. Biol. Rev., 21. 121–139.
Wenyon, C. M., 1926. Protozoology. Balhere, Tindall and Cox, London.
Yakimoff, W., and Kolpakoff, F. A., 1921. Les colites de l'homme dues aux Protozoaires Bull. Soc. Path. Exot., 14, 548–554.
Yakimi W. L, Wassilewski, W. J., and Zweitoff N. H, 1925. Influence dn chlorure de sodium sur les cultures de protozoaires. Ibid. 18, 260–261.
