68 



PL ASMODIOP MORALES 



row of resting spores (fig. 19), double rows (fig. 18, 

 24), or flat, rounded or irregular masses (fig. 17, 20, 

 21 ). When first formed the resting spores are usually 

 polygonal (fig. 17), but later they become more glo- 

 bose. As the}' mature they become knobby and some- 

 what stellate (fig. 18, 19, 20, 22, 23) with intercel- 

 lular spaces between them. Single isolated resting 

 spores may be formed occasionally (fig. 23), and 

 among the normal-sized spores in a cystosorus un- 

 usually large ones may sometimes occur as is shown 

 in figure 17. In these respects S. Betae shows the 

 same variations as other genera. 



Since the resting spores function as sporangia in 

 germination, Nemec called these aggregates spo- 

 rangesori. In germination the resting spores increase 

 in volume and become more rounded in outline (fig. 

 17), their nuclei divide, and the protoplasm cleaves 

 into uninucleate segments which round up (fig. 22) 

 and become zoospores. An opening in the spore wall 

 is soon formed through which the zoospores emerge 

 (fig. 21). The number of zoospores formed varies 

 with the size of the resting spores. Nothing is known 

 about the size of these zoospores, but they are prob- 

 ably similar to those formed in the large zoospo- 

 rangia. Nemec found no evidence of gametes and 

 sexual fusion in S. Betae. 



Like sjjecies of Lic/niera, S. Betae causes no hy- 

 pertrophy or other malformations of the invaded tis- 

 sues. In fact, parasitized rhizodermal cells may re- 

 main alive longer than non-infected cells, according 

 to Nemec. The presence of the parasite, however, 

 causes an accumulation of cytoplasm in infected cells 

 and enlargement of the host nucleus (fig. 1, 5). The 

 latter mav often become irregular and develop an 

 unusually large nucleole. As the plasmodia mature 

 the host protoplasm is reduced to a thin parietal 

 layer and eventually disintegrates. The entrance of 

 the zoospore through the cell wall often leads to a 

 marked reaction. As is shown in figure 25 the en- 

 trance hole becomes plugged up and a conspicuous 

 thickening around this plug is formed on the inner 

 peri])hery of the wall. 



ANISOMYXA 



Nemec, 1913. Bull. Int. Empr. Fran. Joseph 

 Acad. Sci. 18: 18. 



(plate 13, FIG. 26-1.5) 



Plasmodia usually solitary, partly or almost com- 

 pletely filling host cell and conforming with the lat- 

 ter's size and shape ; schizogony unknown : cleaving 

 into groups (sporangiosori) of small and large zoo- 

 sporangia. Sporangiosori usually solitary, rarely 

 more than one in a cell ; indefinite in size and shape ; 

 spring and winter sporangiosori composed of small 

 and large zoosporangia respectively. Zoosporangia 

 variable in size, exit papillae or tubes lacking; pro- 

 ducing four or more uniflagellate ( .'') zoospores. Cy- 

 stosori made up of relatively thick-walled resting- 

 spores ; germination unknown. 



It is not certain from Nemec's account whether or 

 not cystosori composed of thick-walled resting spores 

 are formed in this genus. He reported that the Plas- 

 modium divides into aggregates or sori of polygonal, 

 hexagonal and oval cells which are quite variable in 

 size. In spring and summer, sori of small and uni- 

 form cells are formed (fig. 41), while those produced 

 in the winter are made up of much larger cells (fig. 

 43, 44). In both types of sori, however, the cells are 

 uninucleate at first but later become multinucleate. 

 Because they have tiiin walls and produce several 



PLATE 13 



Soi'olpktium Betae 



(All figures after Nemec) 



Fig. 1. Cell of Beta vulf/aris with two uninucleate para- 

 sites. 



Fig. i. Binucleate stage of S. Betae. 



Fig. 3. Four-nucleate stage; nuclei dividing "promitoti- 

 cally" (?). 



Fig. 4. Host cell with four plasmodia. 



Fig. 5. A large band-shaped Plasmodium surrounding 

 the central vacuole. 



Fig. 6, 7. Large and small zoosporangia with zoospores. 



Fig. 8. Zoospores from sporangia. 



Fig. 9. Plasmodium in which the nuclei lack large nu- 

 cleoli (achromatic stage?). 



Fig. 10. Later stage; nuclei with parietal chromosomes. 



Fig. 11-1.5. Division stages of such nuclei with six well- 

 defined chromosomes. 



Fig. 16. Plasmodium cleaving into resting spores. 



Fig. 17. Young cystosorus (?) with polygonal resting 

 spores. 



Fig. 18-2-2. Cystosori of various sizes and shapes. 



Fig. 19, 20, 22. Cystosori of mature knobby, stellate rest- 

 ing spores. 



Fig. 22. Resting spores with zoospores. 



Fig. 23. Single, isolated stellate resting spore. 



Fig. 34. Cystosorus of empty germinated resting spores. 



Fig. 25. Swollen cell wall at point of entry of zoospore. 



Anisomy.va Plantaffinh 

 (All figures after Nemec) 



Fig. 26. Uniflagellate zoospore. 



Fig. 27. Biflagellate (?) zoospore. 



Fig. 28. Small uninucleate thallus. 



Fig. 29. Binucleate thallus with resting nuclei. 



Fig. 30. Same with both nuclei dividing "promitoti- 

 cally" (?). 



Fig. 31. Tetranucleate thallus with centrosomes and 

 astral rays. 



Fig. 32. Equatorial plate stage of "promitosis" with 

 cap-like centrosomes at poles. 



Fig. 33. Achromatic or "akaryote" (?) stage of nuclei. 



Fig. 34-36. Prophase of meiosis (?). 



Fig. 39. Mature multinucleate plasmodium with some of 

 the nuclei associated in pairs. 



Fig. 40. Zoosporangia cleaving into zoospores. 



Fig. 41. Spring sporangiosorus composed of small zoo- 

 sporangia. 



Fig. i2. Sporangiosorus composed of sporangia arranged 

 in a linear series. 



Fig. 43, 44. Sporangiosori of large multinucleate spo- 

 rangia. 



Fig. 45. Cell with cyst-like sporangia. 



