22 Transactions British Mycological Society. 



show the initiation of hyphal development. Dangeard*, Atkin- 

 son f and others who have worked much on the lower forms 

 of life have suggested a connection between the Chytridiineae 

 and certain groups of the protozoa, and there are many points 

 of contact between the two, both as regards cytology and 

 ontogenetic development. WagerJ called attention to certain 

 protozoan similarities in his investigation of Polyphagus Eu- 

 glenae, and the recent account of the cytology of Synchytrium 

 endohioticum by Curtis § also shows points of resemblance. The 

 absence of cell membranes in many Protozoa is often held to 

 discount the connection between fungi and protist organisms, 

 but large numbers of Protozoa possess well-defined membranes 

 by no means exclusively in the encysted condition, while some 

 fungi are devoid of walls in certain phases of their existence. 

 Thus some of the Foraminifera possess chitinous membranes, 

 and many Radiolarians, Heliozoans and Ciliates have well- 

 defined walls, while in the lower fungi certain stages of the 

 life-cycle are devoid of membranes, and in Synchytrium endo- 

 hioticum the organism is entirely devoid of a wall until a some- 

 what late stage in development. 



Apart from the confusion that formerly existed between 

 certain Chytridiineae and Monads, some organisms are with 

 difficulty classed in the Protozoa or the Chytridiineae, e.g. 

 Rhinosporidium\\ in the Haplosporidia, just as there are some 

 types, e.g. Sappinia pedata, which may be a connecting link 

 between the Protozoa and the Mycetozoa. Again, the Chytri- 

 diineae show marked differences from one another as regards 

 sexuality, but all sexual processes within the group are of a 

 relatively primitive nature and some of these are closely similar 

 to processes of fusion in the Protozoa. The sexuality of the 

 fungi is often looked upon as a residuum, as it were, of the 

 sexual processes existing in the algae. It seems much more 

 reasonable to conclude that like other groups of organisms, both 

 in the plant and in the animal kingdoms, they have initiated 

 their own sexual processes which have been evolved along 

 unique lines in correlation with peculiar environmental con- 

 ditions. With the development of special methods of reproduc- 

 tion, with the initiation of sexuaHty, and with the beginnings of 

 hyphal formation, we may see justification for including, as does 



* Loc. cit. 



t Atkinson, G. F., Some problems in the evolution of the lower fungi. 

 Ann. Myc. vii, p. 441 (1909). 



X Wager, H., The life-history and cytology of Polyphagus Euglenae. Ann. 

 Bot. XXVII, p. 173 (1913). 



§ Curtis, K. M., The life-history and cytology of Synchytrium endohioticum 

 (Schilb.) Perc. etc. Phil. Trans. Roy. Soc. ccx B, p. 409 (1921). 



II Prof. J. H. Ashworth in his recent paper on Rhinosporidium Seeheri refers 

 this genus to the Chytridiineae (Trans. Roy. Soc. Edin. Liii, p. 301 (1923)). 



