4 



THE SIMPLE HOLOCARPIC BIFLAGELLATE PHYCOMYCETES 



Minden, M. 1911. Krypt'fl. Mark Brandenburg 5: 262. 

 Nageli, C. 1844. Zeits'chr. Wiss. Bot. no. 1, 3: 22. 

 Petersen, H. E. 1909. Bot. Tidsskr. 29. 



. 1910. Ann. Mycol. 8: 539. 



Pringsheim, N. 1858. Jahrb. Wiss. Bot. 1: 384. 



. 1860. Ibid. 2: 205. 



Reinsch, P. 1878. Ibid. 11: 283. 



Scbenk, A. 1858. Uber das Vorkommen Contractiler Zel- 



len ira Pflanzenreich. Wurzburg. 



. 1859. Verh. Phys. Med. Gesell. Wurzburg 9: 27. 



Scherffel, A. 1925. Arch. Protistk. 52: 38. 



Schroeter, J. 1886. Cohn's Krypt'fl. Schlesiens 3: 195. 



. 1897. Engler und Prantl, Die Naturpflanzf. I, 1: 



85. 



Sparrow, F. K. 1935. Proc. 6th Intern. Bot. Congress 11: 



182. 



. 1942. Mycologia 34: 113. 



Vuillemin, P. 1908. Prog, rei Bot. 2: 1. 



Walz, J. 1870. Bot. Zeit. 28: 556. 



Weston, W. H. 1935. Proc. 6th Intern. Bot. Congress 1: 



266. 

 . 1941. Symposium on Hydrobiology, p. 130. Univ. 



of Wisconsin Press. 

 Zopf, W. 1878. Verh. Bot. Verein. Brandenburg 20: 77. 



. 1879. Hedwigia 18: 94. 



. 1884. Nova Acta Ksl. Leop.-Carol. Dcut. Akad. 



Nat. 47: 143. 

 . 1887. Abh. Naturf. Gesell. Halle 17: 97. 



Chapter II 



Woroninaceae 



Minden, 1911. Krypt. Fl. Mark Brandenburg 5: 224. 



This family was proposed by Minden for all simple 

 holocarpic species, exclusive of the Lagenidiaeeae, 

 which had been reported to have biflagellate zoo- 

 spores, and as such it included Olpidiopsis, Pseudol- 

 pidium, JVoronina, and Rozella. Minden placed this 

 family in the Chytridiales, and together with the 

 Olpidiaeeae and Synchytriaceae it comprised the so- 

 called Myxochytridiales of Fischer. In creating the 

 Woroninaceae, Minden ignored Petersen's ('09) 

 earlier-named family Pseudolpidiaeeae which was 

 proposed for Olpidiopsis and Pseudolpidium. Since 

 Minden's time numerous other genera have been 

 added to the Woroninaceae, and this family has been 

 rather generally regarded as a convenient dumping 

 ground in the Chytridiales for fungi of this type 

 with biflagellate zoospores, although Petersen and 

 Scherffel in particular emphasized the similarity 

 and relationships of such fungi to the Lagenidiales 

 and Saprolegniales. Sparrow ('42) discarded the 

 family name Woroninaceae entirely, presumably be- 

 cause he believed that the genus JVoronina, after 

 which the family takes its name, belongs in the Plas- 

 modiophorales. While the data at hand favor the 

 view that JV. polycystis, at least, is a member of this 

 order, further intensive study of JVoronina is needed 

 before this question can be settled. Until this rela- 

 tionship is established, the present author is tempo- 

 rarily retaining the Woroninaceae in a restricted 

 sense for Woronina, Pi/rrhosorus and Rosellopsis. 

 By this interpretation it is not, however, to be re- 

 garded as a well established and unquestionable 

 family of closely related genera, but still as a con- 

 venient catch-all for species which are reported to 

 have a plasmodial vegetative stage but which at pres- 

 ent cannot be definitely included in the Plasmodio- 

 phorales. In Woronina, Pyrrhosorus, and the septi- 

 genous species of Rozellopsis the plasmodium is re- 

 ported to undergo segmentation into a number of 

 closely aggregated or loose and separate spores, 

 spore mother cells, sporangia, or resting spores, and 



the suggestion is obvious that such species may pos- 

 sibly be transition forms between the Plasmodio- 

 phorales and the non-plasmodial, non-soric genera. 

 However, our knowledge relative to both groups is 



plate 1 

 Woronina polycystis 



Figs. 1, 2. Biflagellate zoospores. Fischer, '82. 



Figs. 3, 4. Anteriorly biflagellate zoospores. Cook and 

 Nicholson, '33. 



Figs. 5, 6. Early infection stages. Fischer, I.e. 



Fig. 7. Same. Cook and Nicholson, I.e. 



Figs. 8-10. Amoeboid changes in shape and position of 

 young parasite in host cell. Fischer, I.e. 



Figs. 11, 12, 13, 15. Successive stages in development of 

 the parasite and its cleavage into a sporangiosorus. Note 

 local hypertrophy and septation of host hypha. Fischer, 

 I.e. 



Fig. 14. Vacuolate thallus undergoing centrifugal cleav- 

 age. Fischer, I.e. 



Fig. 16. Sporangiosorus. Cornu, '72. 



Figs. 17-20. Maturation, cleavage, and emission of zoo- 

 spores from a sporangium. Fischer, I.e. 



Fig. 21. Small empty sporangiosorus. Cornu, I.e. 



Fig. 22. Cleavage of thallus into a cystosorus. Fischer, 

 I.e. 



Fig. 23. Mature cystosorus. Cornu, I.e. 



Fig. 24. Septate, locally hypertrophied hypha of Sapro- 

 legnia with five cystosori of various sizes and shapes and 

 two empty sporangiosori. Fischer, I.e. 



Fig. 25. Elongate, irregular cystosorus. Cook and 

 Nicholson, I.e. 



Fig. 26. Variously-shaped resting spores from a cys- 

 tosorus. Fischer, I.e. 



Figs. 27, 28. Thick-walled resting spores. Cook and 

 Nicholson, I.e. 



Fig. 29. Germination of cystosorus. Resting spores 

 swelling and vesieulating to become zoosporangia. Fischer, 

 I.e. 



Fig. 30. Germination of resting spores. Cook and 

 Nicholson, I.e. 



