70 



PLASM ODIOPHORALES 



zoospores Nemec regarded tliem as zoosporangia 

 and like in SorolpidUim named the aggregates spo- 

 rangiosori. It is not improbable, however, that some 

 of these sori may be cystosori of relatively thin- 

 walled resting spores, since in describing the cytol- 

 ogy of Anisomi/xa Nemec reported several nuclear 

 changes and appearances (fig. 11-15) which sug- 

 gest the meiotie prophases which precede sporogen- 

 esis. 



Although his account of Anisomyxa is fragmen- 

 tary and not altogether clear, it is evident that 

 Nemec was dealing with a species of the Plasmodio- 

 phoraceae. Wliether or not it represents a new and 

 distinct geims, however, remains to be seen from fu- 

 ture studies. Nemec regarded Anisomi/jra as closelj' 

 related to Rhisomifxa and possibly intermediate be- 

 tween the Plasmodiophoraceae and S_vnchytriaceae. 

 Fitzpatriek ('30) discussed it as a doubtful genus, 

 while Cook ('32, '33) merged it with Ligniera and 

 listed A. Plantaginis {pro parte) as synonymous 

 with L. J unci. The latter worker had previously 

 ('26, '27) found L. Junci in roots of Plantago major, 

 which doubtless influenced his belief that A. I'lanta- 

 gi7iis is a combination of L. Junci and a chytrid. 



A. PLANTAGINIS Nemec. I.e., p. -21. pi. 1, -2. Text-figures 

 1-.). 



Spring and winter sporangiosori variable in size 

 and shape ; irregular, elongate, and oval ; consist- 

 ing of a few to numerous sporangia. Zoosporangia 

 usually remaining attached together in a sorus ; poly- 

 gonal, hexagonal, oval or almost spherical with thin, 

 smooth walls ; spring zoosporangia approximately 

 4.5X6 /i, producing 4 zoospores; winter sporangia 

 10.5X15 /^) forming numerous zoospores. Zoospores 

 oval, 1.5X1-8 /i, spherical, 1.5 /j. in diameter. 



Parasitic in the roots of Plantago lanceolata in 

 Czechoslovakia, without causing hypertrophy of the 

 invaded tissues. 



The zoospores of A. Plantaginis are very small 

 and oval to spherical in shape (fig. 26). Nemec re- 

 ported them as uniflagellate, but he did not state if 

 the flagellum is anteriorly or posteriorly inserted. 

 It is to be noted here that he figured one zoospore 

 (fig. 27) which appears to be biflagellate. It is ac- 

 cordingly quite probable that when this species is 

 studied more intensively the zoospores will prove to 

 be anteriorly biflagellate and heterocont. Nemec pos- 

 tulated that zoospores of two sizes might be pro- 

 duced, because he found cleavage segments of un- 

 equal sizes in several zoosporangia. 



Penetration of the parasite into the host cell has 

 not been observed. Nemec found small oval uninu- 

 cleate thalli in several host cells (fig. 28, 42) which 

 appear to have come from zoosporangia. Such tlialli 

 apparently grow in size as their nuclei divide and 

 eventually become multinucleate plasmodia (fig. 31, 

 39). The nuclear divisions (fig. 30, 32) in the devel- 

 oping Plasmodium resemble the so-called "promito- 

 sis" ty|je and are described by Nemec as vegetative 

 mitosfs in which eentrosomcs and astral ravs are 



usually quite conspicuous (fig. 31, 32). Following 

 completion of the vegetative divisions the nuclei lose 

 their chromatin, and the nucleole is reduced to a 

 small globule (fig. 33). The cytoplasm, on the other 

 hand, becomes filled with small deeply stainable 

 granules. This stage is followed shortly by another in 

 which dense chromatic granules, rods, and bands 

 appear at one side of the nuclei (fig. 36, 37) and sug- 

 gest synaptic phases of meiosis. These stages initiate 

 the reproductive divisions, according to Nemec. 

 However, figures 33 to 38 are strikingly like the 

 "akaryote" phase and prophase stages of meiosis 

 which in other genera have been interpreted as ini- 

 tiating sporogenesis. It is not clear from Nemec's ac- 

 count whether these stages precede the formation of 

 spring or winter sori. 



The mature plasmodium does not become envel- 

 oped by a wall like in Sorolpidium but cleaves di- 

 rectly into sporangia which remain aggregated and 

 form sori. The zoosporangia are polygonal (fig. 41) 

 at first but later become oval and spherical (fig. 40). 

 In the small spring sporangia, two nuclear divisions 

 of the mitotic tj'pe occur, and the protoplasm cleaves 

 into four segments which become zoospores (fig. 40). 

 In the larger winter sporangia numerous mitoses 

 occur, producing multinucleate zoosporangia (fig. 

 42—44) which give rise to numerous zoospores (fig. 

 21, 22). No exit papillae or tubes were observed by 

 Nemec and nothing is known about the emergence of 

 the zoospores from the sporangia. 



Nemec found no evidence of sexual fusions in 

 Anisomi/.ra, but he pointed out that tlie nuclei in the 

 mature plasmodium (fig. 39) are often associated in 

 pairs, implying perhaps that karj'ogamy may take 

 place. This suggestion is further implied by his fig- 

 ures of synaptic (fig. 36. 37) and diakinetic (fig. 

 38) division stages. In addition to the two types 

 of sporangiosori Nemec also found several large, 

 sporangium-like oval cysts (fig. 45), 14.5- 20;it X 

 20-26 fi. which he believed might possibh' be cysto- 

 sori. Whether or not these are large isolated resting 

 spores of A. Plantaginis is not certain. 



TREMATOPHLYCTIS 



Pcatouillard, 1918. Bull. Soc. Mycol. France 34: 

 86, fig. A-G. 



(plate 14. fig. 1-6) 



Patouillard established this genus to include a spe- 

 cies, T. Tjcptodesmiae, which parasitizes petioles and 

 leaves of Leptoc/esmia congesta in Madagascar. His 

 diagnosis was based on dried material eollected by 

 V^iguier in 1912, and there is very little evidence in 

 his brief description to warrant inclusion of this spe- 

 cies in the Plasmodioplioraceae at the present time. 

 The infected leaves and petioles become thick, fleshy 

 (fig. 1,2), and reddish in color, and later numerous 

 round or irregular, 0.5 to 3 unn. high, solitary or ag- 

 gregated, open, aceium-likc pustules filled with yel- 

 low spores appear in the infected areas. 



