26 H. MARSHALL WARD. 



this manner, apparently, it came to be widely believed that in such 

 cases as Sordaria, 1 Penicillium? Sphaeria lemanece, 3 and Chaetomium 

 the sexual process is essentially the same as that described for the 

 simpler Erysiphece. 



All the observers agreed in the main that the asci are either parts 

 of the Ascogonium, or female sexual organ (Sphcerotheca, Podosphcera), 

 or are developed by budding from it, in each case no doubt after the 

 Ascogonium had received something from the male organ (Pollinodimn) 

 attached on its surface. Meanwhile, investigation was not confined to 

 the Ascomycetes. 



The researches ofBrefeld, 4 Van Tieghem, 5 and others 6 demonstrated 

 a simple form of sexual reproduction in the Mucorini, now so well 

 known that we need not dwell upon it. It is interesting to note in 

 passing, however, that Ehrenberg had discovered the conjugation of 

 Syzigites so long ago as 1820. 7 



We now pass to the discovery of the true nature and sexual organs 

 of the Pero7iosporeo3 by De Bary, who, in a series of masterly memoirs, 8 

 has made this group and its allies a special study. De Bary showed 

 that in certain members of this group an antheridium bores into the 

 oogonium, sending a " fertilising tube " into the oosphere contained 

 therein ; the oosphere then becomes an oospore, and capable of germi- 

 nation. 



A considerable amount of labour had been devoted to the study of 

 the Saprolegnke since Pringsheim's first publication, much of it by this 

 investigator himself, 9 and among other remarkable discoveries his 

 observation that, in certain cases, the oospores become normally 

 developed and capable of germination -without any male organs being 

 formed at all, is to be noted. Pringsheim himself termed these oos- 

 pores parthenogenetic. 10 We may pass over the controversy between 



1 Gilkinet, "Recherches Morphologiques," 'Bull. Acad. r. de Belg.,' ser. 2, 1S74. Woronin, 

 'Beitr. z. Morph., &c.,' R. iii. 



2 Brefeld, ' Schimmelpilze," ii. 



3 Woronin, ' Beitr. zur Morph., &c.,' R. iii. 

 * ' Schimmelpilze,' H. i. 



5 ' Ann. des Sc. Nat.,' ser. 6., t. i. 

 De Bary, ' Beitr. z. Morph.,' i. 



7 This is the date in Sachs' ' Geschichte der Botanik,' p. 473. De Bary, ' Beitr.,' i., p. 74, 

 gives the date 1829. 



8 'Ann. des Sc. Nat.,' ser. 4, vol. xx, and later, ' Beitriige zur Morph., R. ii ; ditto, R. iv. 

 «Bot. Zeit.,' 1881. 



9 'Jahrb. fur wiss. Bot.' 



10 ' Jahrb. fur wiss. Bot.' is. 





