448 AQUATIC PHYCOMYCETES 



NOWAKOWSKIA Borzi 



Bot. Centralbl., 22 (1): 23. 1885 



(Fig. 25 A-D, p. 411) 



Thallus monocentric, eucarpic, consisting of a sporangial rudiment 

 (the body of the encysted zoospore) and from one to five rhizoids the 

 tips of which are endobiotic; zoosporangium inoperculate, zoospores 

 posteriorly uniflagellate, with a single globule, formed within the spo- 

 rangium, liberated upon the dissolution and contraction of the spo- 

 rangium wall as a flagellate compact motile group which disassociates 

 into successively smaller groups and finally into individuals; resting 

 spore not observed. 



Parasitic on Hormotheca. 



A monotypic genus. Differing from Rhizophlyctis in its method of 

 zoospore liberation and the behavior of the freed spore mass. Some 

 investigators consider this behavior abnormal and regard the fungus 

 as a species of Rhizophlyctis. From the large numbers of plants devel- 

 oped in Borzi's cultures, it is hardly probable that he would have 

 selected atypical ones in characterizing his genus. 



NOWAKOWSKIA HORMOTHECAE Borzi 



Bot. Centralbl., 22 (1): 23, pi. 1, figs. 1-10. 1885 

 Sporangium free in the medium, fully developed in from four to six 

 hours, nearly spherical, 4-16 \x in diameter, with a smooth delicate 

 colorless wall which gives a cellulose reaction, contents finely granular, 

 multinucleate; rhizoids mostly three, rarely up to five, delicate, tapering, 

 emerging from any point on the surface, unbranched or occasionally 

 branched, varying in direction and length, polyphagous; zoospores 

 minute, elongate with a median constriction, 1 \x long, flagellum 

 posterior (?), 4-5 \i long, plasma thin, homogeneous, with a basal, 

 anterior, or lateral refractive droplet, movement of the group rolling, 

 duration of individual motility only a few minutes; resting spore not 

 observed. 



Parasitic on germinating spores of Hormotheca sicula, Italy. 

 The cause of an epidemic in cultures of the host. 



