THE CATALYST ENTELECHY IN DIFFERENTIATION 213 



16 F. G. Fischer, E. Wehmeier, and L. Jiihling, Nachr. Gesell. Wiss. zu Gottingen 

 (1934) (IV), 9, 394. 



" C. H. Waddington, J. Needham and J. Brachet, Proc. Roy. Soc, B (1936) 120, 

 173. 



18 Proc. Kon. Akad. Wetenskap. Amsterdam (1933) 36, 423. 



w Zeit. physiol. Chem. (1934) 225, 103. 



20 C. H. Waddington, Science Progress (1934) 29, 336. 



21 C. H. Waddington, "Morphogenetic Substances in Early Development," Trans. 

 du Congres du Palais de la Decouverte, Hermann, Paris, 1938. 



22 Science (1942) 96, 455. 



23 S. A. Harris el al., J. Am. Chem. Soc. (1944) 66, 1756. 



24 "Genetics and the Origin of Species," Columbia Univ. Press, 1941, p. 22. 



25 See J. Alexander & C. B. Bridges, "Colloid Chemistry," Vol. II, p. 13, Reinhold 

 Pub. Corp., 1928. 



26 See Ann. Rept. Smithsonian Inst. (1913) 261-73; Soc. franc, phys. (1914) 55, 3; 

 57,3. 



27 Science, 66, 84-87; (1928) 67, 82. 



28 Cold Spring Harbor Symp. (1941) 9, 151-65; 290-308. 



29 lib. cit., p. 309ff. 



30 According to L. Zechmeister [Chemical Reviews (1944) 34, 278] the calculated 

 number of stereoisomers for naturally occurring carotenoids are, for example, as 

 follows: a-carotene, 32; /3-carotene 20; 7-carotene 64; lycopene, 72; crocetin, 20; 

 vitamin A, 4. (J. A.) 



31 See, e.g., J. Alexander, hid. Eng. Chem. (1939) 31, 630-642. 



32 lib. cit., p. 110. 



33 R. Kuhn, F. Moebus, and D. Jerchel, Berichte (1938) 71, 1541. 

 Si Ann. Inst. Pasteur (1900) 14, 139-189. 



35 Helsingfors Univ., Thesis, 1930, "Ueber Enzymbildung in Bacterien"; "Enzyma- 

 tische Adaptation bei Microorganismen," Ergeb. Enzymjorsch. (1938) 7, 350-376. 



36 H. E. Rhoades, /. Bad. (1941) 42, 99-115. 



37 See Alexander, "Colloid Chemistry," Vol. V., p., 562-8, Reinhold Pub. Corp., 

 1944. 



38 Alexander, "Colloid Chemistry," Vol. II, (1928) pp. 361-6. 



39 W. A. Helbig, in Alexander, "Colloid Chemistry," Vol. VI (1946), pp. 814-39. 



40 See R. Goldschmidt, lib. cit., p. 309. 



41 F. R. Lillie, Science (1916) 43, 611; /. Exptl. Zool. (1917) 23, 371. 



42 F. A. E. Crewe, Proc. Roy. Soc. (1923) 95 B, 256; O. Riddle, Am. Nat. (1924) 58, 

 167; M. M. Zowandowsky, Trans. Lab. Exp. Zool. (Moscow) (1928) 4, 9. 



43 Biol. Bull. (1902) 9, 75. 



44 Compt. rend. soc. biol. (1886) 38, 87. 



45 J. T. Presley, /. Heredity (1934) 45, 485. 



46 R. T. Hill, Endocrinology (1937) 21, 495, 633. 



47 Bull. Biol. Fr. Belg., (1936) 70, 241. 



48 "Parthenogenetic merogony or cleavage without nuclei in Arbacia punctulata," 

 Biol. Bull. Wood's Hole (1936) 71, 101. 



49 The eminent Jacques Loeb, who described this activation about forty years ago, 

 used to tell, with amusement, that he was privately consulted by two nervous maiden 

 ladies to find out whether sea-bathing would be perfectly safe for them. 



In 1907 J. H. McClendon [Biol. Bull. (1907) 12, 142; Arch. Entw. mech. (Roux) 

 (1908) 26, 662] had sucked out the nucleus from an echinoderm egg and fertilized 

 parthogenetically the non-nucleated cell, or "merogen," that remained. 



50 Biol. Rev. (1941) 16,301. 



