28 



PL ASMODIOP MORALES 



vious studies (02, '03) on bacteria in relation to tlie 

 niyxoniycetes. Pinoy (05, 07) concluded that bac- 

 teria were essential to the development of P. Brassi- 

 cae and described the relationsliij) between them as 

 true symbiosis, a viewpoint which Vouk (13) later 

 supported. Pinoy reported that the spores of the 

 fungus will germinate only in the presence of these 

 bacteria, and as the zoospores or amoebae enter the 

 host they are accompanied by cocci which continue 

 to live in constant association with the parasite 

 throughout its entire life cycle. Chupp (17) re- 

 peated Pinoy's experiments to some degree and 

 found that bacteria are absent in small, young swell- 

 ings and do not appear until the galls have become 

 quite large and old. Furthermore, instead of cocci, 

 he found the most prevalent form to be a motile, rod- 

 shajjcd bacillus which forms yellowish, ojjalescent 

 colonies on nutrient media. Chupp concluded from 

 his experiments that bacteria do not enter the host 

 with the amoebae and that the disease must attain a 

 certain advanced stage before the bacteria can enter. 

 According to him, they are not essential to the devel- 

 opment of P. Brassicae, but as Sorauer (08) had 



previously jjointed out, they may act in decomposing 

 the host cell wall and thus liberating the spores. 



Naumov ('2.5) likewise failed to find bacteria in 

 young galls, while Fedotowa (30) reported that bac- 

 teria may be present within one and a half to five 

 months after infection. He found that P. Brassicae 

 spores may be easily freed of bacteria by immersing 

 them for five minutes in a .001 per cent corrosive 

 sublimate solution. From diseased roots he isolated 

 one bacillus and two coccus forms which when in- 

 jected into roots in pure culture produced no signs 

 of hy])ertrophy or injury, Fedotowa tlnis showed 

 that bacteria are in no way necessary to spore ger- 

 mination, entrance of the amoebae, or to the nutrition 

 of the Plasmodium. 



Plasniodiophora Brassicae and Cellular Inclu- 

 sion of Cancer Cells, Small Pox, and Rabies 



At the close of the last century when animal path- 

 ologists were actively engaged in trying to prove the 

 parasitic nature of the inclusions found in carcinoma 



Fifr. -2-2, i3. Anteriorly biflagellate, heterocont zoospores. 

 Leclinpliam, '34. 



FifT. 2i. Restinjr spores attached to root hair tip, small 

 spherical myxamoeba within the cell and two myxamoi-ba 

 entering through a swollen gelatinized region of the wall. 

 Rochlin, '33. 



Fig. :?.5. Three parasites lying in a swollen gelatinized re- 

 gion of tlie root liair wall. Rochlin, I.e. 



Fig. 2G. Entry of the parasite through the epidermal cell 

 wall of the root of B. arvensis. Note other swollen and dis- 

 organized regions where additional parasites have entered. 

 Rochlin, I.e. 



Fig. 27. Entry of an amoeba in root hair. Honig, I.e. 



Fig. 38. Swollen root hair of cabbage with a living myx- 

 amoeba. Woronin, I.e. 



Fig. 39. Uninucleate myxamoeba in root hair wliich is 

 locally swollen. Cliupp, I.e. 



Fig. 30. Division of a myxamoeba by fission. Chupp, I.e. 



Fig. 31. Early stage in cell wall penetration by a young 

 Plasmodium. Kunkel, '18. 



Fig. 33. Later stage. Kunkel, I.e. 



Fig. 33. Young plasmodium passing through cell wall. 

 Kunkel, I.e. 



Fig. 34. Large living amoeboid plasmodium moving 

 within liost cell. Note pseudopods at the anterior and vacu- 

 oles in the posterior end. Woronin, I.e. 



Fig. 3.5. Large saprophytic amoebae or ])lasmodia out- 

 side of host. Honig, I.e. 



Fig. 3(). Root hair filled with meronts, possibly incijiient 

 zoosporangia. Chupp, I.e. 



Fig. 37. Empty and developing zoosporangia in a root 

 hair wliieli have been formed from a plasmodium. Cook and 

 Schwartz, I.e. 



Fig. 38. Uninucleate segment of plasmodium which will 

 develop into a zoosporangium. Cook and Schwartz, I.e. 



Fig. 39. First mitosis (meiotie?) in incipient zoosporan- 

 gium. Cook and Schwartz, I.e. 



Fig. 40. Binucleate stage of same. Cook and Schwartz, 

 I.e. 



Fig. 41. Zoosporangium with four ineijiient zoospores. 

 Cook and Schwartz, I.e. 



Fig. 43. Same with three fully formed zoospores. Cook 

 and Schwartz, I.e. 



Fig. 43. Nonflagellate zoospores from zoosporangium. 

 Cook and Schwartz, I.e. 



Fig. 44—46. Encysted myxamoeba and young plasmodia. 

 Milovidov, "31. 



Fig. 47. Large segmented jilasniodium, the segments of 

 which have encysted. Cook and Schwartz, I.e. 



Fig. 48. Binucleate plasmodium with numerous cbondrio- 

 somes. Milovidov, I.e. 



Fig. 49. Resting nuclei of large plasmodium. Cook and 

 Schwartz, I.e. 



Fig. 50. Same in young plasmodium. Nawaschin, "99. 



Fig. 51. Same in amoebae with centrosomes and astral 

 rays. Milovidov, I.e. 



Fig. 53. Early prophase of "promitosis" with chromatin 

 in the form of numerous granules. Nawaschin, I.e. 



Fig. 53. Equatorial plate stage of "promitosis" with di- 

 vided nucleole. Nawaschin, I.e. 



Fig. 54. Same stage. Cook and Schwartz, I.e. 



Fig. 55, 56. "Double anchor" stage of "promitosis." Na- 

 waschin, I.e. 



Fig. 57, 58. Late anaphase and telophase of "promitosis." 

 Nawaschin, I.e. 



Fig. 59-61. Successive stages In development of the 

 "akaryote" stage. Cook and Schwartz, I.e. 



Fig. 63. Akaryote stage. Cook and -Schwartz, I.e. 



Fig. 03. Siiireme stage of the first sporogonic (meiotie?) 

 mitosis. Lutman, I.e. 



Fig. 64, 65. Synapsis and i)ossibly diakinesis, respec- 

 tively. Milovidov, I.e. 



Fig. 66. Early prophase of meiosis. Terby, '34. 



Fig. 67. Synapsis. Terby, I.e. 



Fig. 68. Strepsitene. Terby, I.e. 



Fig. 69, 70. Diakinesis. Terby, I.e. 



Fig. 71. Polar view of equatorial plate stage showing 

 eight chromosomes. Terl)v, I.e. 



Fig. 73. Profile view of equatorial plate stage, first divi- 

 sion. Lutman, I.e. 



Fig. 73. Polar view of same showing eight large chro- 

 matic bodies. Lutman, I.e. 



