80 



THE SIMPLE HOLOCARPIC BIFLAGELLATE PHYCOMVCETES 



This species has been reported but twice, and is so 

 incompletely known that it is impossible to deter- 

 mine whether or not it is identical to L. zopfii. 

 De Wildeman, however, was inclined to regard the 

 fungus which he found at Nancy as distinct from 

 L. zopfii and possibly related or identical to Soro- 

 kin's Aphanistis pellucidia. It is to be noted here, 

 however, that the zoospores of the latter species are 

 uniflagellate, according to Sorokin. 



According to Klebahn, L. syncytiorum has but 

 little deleterious effect on the host cells at first. Nu- 

 clear division may proceed normally for a time, but 

 cell division is not completed. As a result, infected 

 cells may be multinucleate with incompletely formed 

 cross walls, and 2—4 times their normal length. In 

 these respects the effects are very similar to those 

 caused by Vlasmophagus in the same host (de Wilde- 

 man, '95, p. 220). De Wildeman, on the other hand, 

 failed to observe the effects described by Klebahn, 

 and found that the thallus may be confined to a 

 single cell the content of which it soon destroys. Ac- 

 cording to Klebahn, all host nuclei in infected cells 

 are not similar in size and shape. Some may be large 

 while others are quite small, suggesting perhaps a 

 previous disturbance in chromosome distribution. As 

 the parasite matures the effects on the host become 

 more pronounced. The plastids, nuclei, and the re- 

 mainder of the protoplasm are gradually killed and 

 largely absorbed. 



The irregular thalli of this species resemble some- 

 what those of L. ellipticum, while those in w' ich t''e 

 segments are arranged like a string of beads look 

 similar to thalli of Mysocytium megastomum. 



L. ELLIPTICUM de Wildeman, 1893a. Ann. Soc. Beige 

 Micro. 17: 5. PI. 1, figs. 1-11. 1893b. Jour. Roy. Micro. 

 Soc. 1893: 765. 



Thallus thick, deeply lobed and irregular with nu- 

 merous blunt protuberances, rarely becoming fila- 

 mentous, non-septate and continuous with one or 

 more short exit tubes which project only slightly be- 

 yond the surface of the host. Zoospores, oogonia and 

 antheridia unknown. Oospores elliptical, 10-14 X 

 20-30 p., with a thick irregularly warty wall, and a 

 granular refractive content; germination unknown. 



Parasitic in rhizoids of mosses in Belgium. 



De Wildeman was not certain about the relation- 

 ship of this species to Lagenidium, and in view of 

 the fact that no zoospores, oogonia and antheridia 

 have been observed it is herewith presented as very 

 doubtful. The oospores are usually numerous, but 

 de Wildeman did not determine whether or not they 

 are parthenogenetic. 



L. CLOSTERII de Wildeman, 1893b. Ann. Soc. Beige 

 Micro. 17: 48. PI. 6, figs. 1-5. 



Thallus mycelium-like, consisting of long, 

 straight, curved, twisted, branched, cylindrical fila- 

 ments of more or less uniform. 1.8—2.8 /x, diameter; 

 occasionally swollen, vesicular, and irregular, usu- 

 ally unconstricted; becoming septate at maturity; 

 segments transformed into sporangia or gametangia. 



Sporangia elongate and cylindrical; exit tubes 

 greatly inflated, globular and appressorium-like in- 

 side of host wall and extending a short distance or 

 20-30 /x beyond its surface. Zoospores bean-shaped, 

 3.8 /u X 5.6—6.3 [x; formed in an extramatrical vesi- 

 cle. Oogonia inflated and broadly spindle-shaped, 

 antheridia less so. Oospores spherical 10-15 <t, with 

 a double-layered wall, exospore warty, verrucose or 

 knobbed ; germination unknown. 



Parasitic in Closterium striolatum in Belgium 

 (de Wildeman, I.e.); Closterium sp.. in Denmark 

 (Petersen, '09, '10), Czechoslovakia (Cejp, '33, 

 '35) and North Carolina, U. S. A. (Couch, '35). 



The warty or verrucose oospores of this species 

 are very similar to those of L. entophytum and L. 

 sopfii, but differ from those of these two species 

 by the possession of a large central refractive glob- 

 ule, according to de Wildeman. Minden regarded 

 this species as doubtful, but Couch thought it may 

 be valid. The latter worker pointed out that it may 

 readily be mistaken for a species of Pythium be- 

 cause of its fine, filamentous thallus, but the large 

 refractive granules in the cytoplasm, however, dis- 

 tinguish it rather clearly. 



L. INTERMEDIUM de Wildeman, 1895. Ann. Soc. 

 Beige Micro. 19: 96. PI. 4, figs. 10-13. 



Thallus irregular, rather thick, frequently 

 branched and sparingly septate. Sporangia tubular, 

 elongate and cylindrical with a single exit tube which 

 may be rarely inflated inside of the host wall, con- 

 stricted as it passes through, and extends a short or 

 long distance beyond the surface of the host. Zoo- 

 spores, oogonia and antheridia unknown. Oospores 

 globular, smooth and thick-walled; germination un- 

 known. 



Parasitic in Closterium ehrenbergii in Belgium 

 (de Wildeman, I.e.) ; Closterium sp., and Plettro- 

 taenium trabecula in Bohemia (Cejp, '35). 



This species has been observed but twice and is 

 imperfeclly known. Cejp did not add anything; of 

 significance to the original description of de Wilde- 

 man. By its elongate and cylindrical segments this 

 species resembles L. rahenhorstii, and according to 

 de Wildeman it stands intermediate between the lat- 

 ter species and L. entophytum. 



De Wildeman (I.e.. p. 75; pi. 2, fig. 22) also fig- 

 ured an extensively lobed parasite in Euastrum 

 oblongum which he believed relates to Lagenidium. 

 He did not, however, observe the zoospores and 

 oospores, and hence it is difficult to determine the 

 identity of the species. He, nonetheless, believed it 

 may be the same fungus which Reinsch ('78, pi. 17, 

 fig. 5) figured in E. oblongum. Cornu ('77), how- 

 ever, believed Reinsch's fungus relates to Mysocy- 

 tium lineare. 



L. REDUCTUM (de Wildeman) nov. comb. 



Lagenidiopsis reducta de Wildeman, 1896. Ann. Soc. 

 Beige Micro. 20: 109. Pis. 6-7. 



Thallus filamentous, elongate, tubular, cylindri- 

 cal, straight, curved and undulate, slightly inflated 



