3 86 
Kauffman. — A Contribution to the 
to preclude any final results on this point. If we could start with a dioecious 
form of Saprolegnia and obtain the results here obtained, the outlook would 
be more encouraging. Of course if we were to consider that the normal 
condition of Saprolegnia hypogyna is one in which the antheridium is 
simply suppressed, and that the new conditions have merely removed the 
obstacle which had hitherto prevented its development, sex-determination 
would not be touched by the reactions detailed in this paper. But I am 
not at all sure that the hypogynous cell must be so considered. At any 
rate, the question of sex-determination remains one of the most attractive 
problems of biology. 
Literature Cited. 
The literature is fully reported by Humphrey up to 1893, and by Klebs up to 1900. The 
following are referred to in the text. 
Bary, A. de (’81) : Untersuchungen liber Peronosporeen und Saprolegnieen. Beitrage zur Morph, 
und Phys. der Pilze, Reihe IV. 
(’88) : Species der Saprolegnieen. Bot. Zeit., 1888, xlvi, pp. 597, 613, 629, und 645. 
Benecke, W. (’95) : Die zur Ernahrung der Schimmelpilze notwendigen Metalle. Jahrb. f. w. Bot., 
1895, xxviii, p. 485. 
Cornu, M. (’72) : Monographic des Saprolegniees. Ann. Sci. Nat, Bot, ser. 5, tome xv, 1872, p. 5. 
Davis, B. M. (’04) : Oogenesis in Saprolegnia. Bot. Gaz., 1904, xxxv, p. 347. 
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Saprolegnieae. Trans. Roy. Irish Acad., 1895, xxx. 
(’99): The alleged Fertilization in the Saprolegnieae. Ann. Bot., 1899, xiii. 
Humphrey, J. E. (’93) : The Saprolegniaceae of the United States. Trans. Amer. Phil. Soc. N.S., 
xvii, 1893, p. 63. 
Klebs, G. (’99 and ’00) : Zur Physiologic der Fortpflanzung einiger Pilze. II. Jahrb. f. wiss. 
Bot., 1899, xxxiii, p. 513. III. Jahrb. f. wiss. Bot., 1900, xxxv, p. 80. 
(’96) : Die Bedingungen der Fortpflanzung bei einigen Algen und Pilzeu. Jena, 1896. 
(’03) : Willkiirliche Entwickelungsanderungen bei Pflanzen. Jena, 1903. 
(’06) : Uber Variationen der Bliiten. Jahrb. f. wiss. Bot., 1906, xlii, p. 155. 
Maurizio, A. (’94) : Zur Entwickelungsgeschichte und Systematik der Saprolegnieen. Flora, 1894, 
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Molisch, H. (’95) : Bericht. d. Wien. Akad., 1895, civ, p. 795 (discussed by Pfeffer in Plant 
Physiol., Eng. Ed.) 
Naegeli, C. (’ 47 ) : Zeitschrift fur wiss. Bot., 1847, Hefte 1, 3, und 4. 
Pfeffer, W. (’84) : Locomotorische Richtungsbewegungen durch chemische Reize. Unters. aus 
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Schleiden, M. J. (’42) : Grundziige der Bot., 1. Aufl., Leipzig, 1842, p. 264. 
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(’04) : On Fertilization in the Saprolegnieae. Ann. Bot., 1904, xviii, p. 541. 
Unger, F. (’43) : Einiges zur Lebensgeschichte der Achlya prolifer a. Linnaea, 1843, xvii, p. 127. 
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