THE SEXUALITY OF THE FUNGI. 25 



system of the fungi. In the last case we may at least succeed in 

 attracting more attention to the direction in which modern research 

 in this region is impelling the more thoughtful biologists, and so call 

 forth confirmatory evidence or criticism of unseen fallacies. 



If we neglect a few isolated observations as having led to no general 

 views on the subject, we may regard Pringsheim's discovery of the 

 sexual organs in the Saprolegnice in 1858 x as the starting point of our 

 knowledge of the sexuality of the fungi. This observation was made 

 at a time when attention was being drawn particularly to the sexes of 

 the Algfe by the researches of Thuret, De Bary, Cohn, Nageli and 

 others ; and the Saprolegnice were then, and for a long time afterwards, 

 regarded as Algse. 



Since that time numerous cases of the occurrence of sexual organs 

 have been described among other fungi, chiefly by the labours of De 

 Bary and the school of cryptogamic morphology practically established 

 by him and his pupils. 



With De Bary's brilliant researches on the Ascomycetes? and 

 especially the Urysiphece, 3 a point was reached where a definite opinion 

 on the sexuality of the fungi became accepted ; and the conclusions 

 drawn from the study of Sphcerotheca, Eurotium, and Peziza led to the 

 view that the fruit-body of a higher fungus results from a process of 

 fertilisation preceding the development of asci, and that Hofmeister's 

 supposition that the asci are sexual organs was to be abandoned. 



In 1871 Janczewski 4 described the sexual organs in Ascobohis fur- 

 furaceus. Other researches by Baranetski, Gilkinet, Woronin, Van 

 Tieghem, and Brefeld were considered to support the then generally 

 received opinion that the fungi, while differing considerably as to 

 their forms and mode of producing spores and fructification, probably 

 all develope their chief reproductive bodies as the consequence of a 

 sexual process. 



When in 1874 Stahl demonstrated the sexuality of a Lichen, 5 the 

 matter seemed to be placed beyond doubt ; and it was freely admitted 

 that in the cases — now somewhat numerous — where a definite union 

 of sexual organs could not be established, that the failure was largely 

 due to the extraordinary difficulties attending the investigation. In 



1 Sachs, ' Geschichte der Botanik.' 



2 ' Ueber die Fruchtentwickelung der Ascomyceten,' 1863. 



3 ' Beitrage zur Morph., &c, der Pilze,' R. iii., 1870. 

 1 *Bot. Zeitg.'1871. 



5 *Bot. Zeitg.,' 1874. 



