OI.I'IDIOI'.xlll Vc BAI 



Parasitic in Draparnaldia glomerata in Russia, 

 causing marked hypertrophy of the host cells. 



The above description is taken from a German 

 resume of the Russian text. Because the thallus of 



/'. deformans is amoeboid and Undergoes division 



into secondary thalli, Serbinow was uncertain about 

 the tazonomic position of this species, and he accord- 

 ingly assigned it only temporarily to Pseudolpidium. 

 Another questionable and unidentified species of 

 Pseudolpidium was found by EZrafka and Miller 

 '26 in the alimentary tract of the boll weevil in 

 Georgia.These workers did not study its life cycle 



and merely reported and figured a few spiny, oval. 



in ii,, L2 50 /*, resting spores or sporangia ( ?). 

 Whether these bodies are parthenogenetic resting 

 spores or spiny zoosporangia of Pseudolpidium or 

 relate to an entirely different organism is not evident 

 from Krafka and Miller's description. 



Whether or not the parasite which Nagler (11) 

 found in Euglena sanguinea and described as Pseu- 

 dosphaerita Euglenae belongs here is questionable. 

 The presence of long exit tubes seems to exclude it 

 from Pseudosphaerita so far as this genus is now 

 known, and the zoosporangia are suggestive of those 

 of Olpidiopsis and Pseudolpidium. However, until 

 the /.oospores have heen observed the identity of 

 Nagler's fungus will remain doubtful. 



PSEUDOSPHAERITA 

 Dangeard, 1895. Le Bot. -t : 24:3. 



(plate I I) 



Thalli intramatrical, solitary or up to 25 in a cell, 

 appearing to be more or less naked hut immiscible 

 with the host protoplasm when young; becoming in- 

 vested with a definite wall or membrane as they ma- 

 ture: oval, spherical, coiled, elongate, or slightly 

 irregular. Zoosporangia of same shape and size as 

 the mature thalli; exit papillae apparently lacking; 



opening by a rupture (?) of the wall. Zoospores 

 heterocont or isocont | ?) with flagella inserted near 



the .anterior end. short flagelhini directed forward 

 in swimming while the longer one is dragged along 

 behind; liberated to the outside ( ? ) or inside tin- 

 host cell where they may start secondary infections. 

 Resting spore unknown. 



This genus resembles Sphaerita superficially but 

 according to Dangeard'x latest study i '.'!•'! ) differs 



fundamentally from the latter genus by the division 

 or segmentation of its thallus after each successive 



mitosis (figs. 9—15), with the result that multinu- 

 cleate thalli are rarely formed. The segments be- 

 come progressively smaller with each division and 

 art eventually transformed directly into zoospores 



(fig. IT i. Dangeard, nevertheless, figured multinu- 

 cleate thalli both in 1895 (fig. 3) and 1933 i fig. 8), 

 which suggested to him that he may have had two 

 organisms at hand or that Pseudosphaerita has two 

 < streme types of development with intermediate 



stages between. In his latter contribution, Dangeard 

 held to the former possibility, while Mitchell ( '28 ) 

 Upheld the second viewpoint. The latter worker re 

 ported that the parasite which he found in Euglena 

 caudata segments after each nuclear division ( figs. 

 19—22), while the one occurring in /•.'. viridis de 

 velops a multinucleate thallus and finally under- 

 goes cleavage into spore rudiments (figs. J.'t 27). 

 According to his account these are but different 

 stages of the same parasite. However, the identity 

 of Mitchell's species is uncertain because he did not 

 observe the zoospores nor the number, relative 

 lengths and position of the flagella. The similarity 

 in types of development nonetheless suggests that 

 his species are the same organisms studied by Dan 

 geard in 1895 and 1933, and for this reason they are 

 included in Plate It. Jahn ('33) maintained that 

 the species with the multinucleate "plasmodial" 

 stage (figs. 2.3-27) is Sphaerita dangeardii Chattoo 

 and Brodsky, 1909. Obviously, more intensive study 

 of both Sphaerita and Pseudosphaerita is necessary 

 before the latter genus can be adequately diagnosed 

 and discussed in relation to other genera with bi- 



flagellate zoospores. 



Dangeard and Mitchell did not observe infection 

 of the host, SO that it is not known whether the /oo- 

 spores enter the Euglena cell directly or germinate 

 on its surface and then leave the empty spore case 

 and penetration tube behind as in Olpidiopsis, Eury- 

 chasma, etc. In instances where the zoospores .ire 

 discharged within the host cell (fig. 18) they appar- 

 ently develop directly into thalli (6—8). As noted 

 above. Dangeard figured several multinucleate thalli 

 which appear to be undergoing cleavage ( figs. f. 5 ). 

 but this appearance is due to the complete or partial 

 disappearance of the lines of demarkation of the 

 zoospores in the late stages of development, accord- 

 ing to Dangeard's latest account. As a result the ma- 

 ture thallus may appear to be homogeneous and 

 multinucleate (figs. :J. I (i ) or divided into large ir- 

 regular multinuclear segments (tigs, k 51). The 

 type of cytokinesis suggested by the latter two fig- 

 ures appears to be quite different from that illus- 

 trated in figures 10 to If and 19 to 22. Here the 



whole thallus appears to be partitioned or frig 



merited after each mitosis, while in figures f, ;">. and 

 27 it looks as if the content of a sporangium has un- 

 dergone endogenous division with the original thal- 

 lus wall remaining intact. 



The method by which the /oospores get out of the 

 host is not known. According to Dangeard they are 

 liberated within the host, but it is obvious that some 



of them eventually escape. Otherwise additional 



hosts would not bcc< ■ infected. Mitchell suggested 



that they might escape through the "mouth" vacu- 

 ole or by rupture of the host cell. The mature free 



swimming zoospores are pyriform .and pointed at the 

 apex with two unequal flagella inserted a short dis- 

 tance back of the anterior end ( fig- I )■ Their move 

 ineiit in swimming is more even, straight forward 

 .and less irregular and darting than in Sphaerita. 



