Freeman: OBSERVATIONS ON CHLOROCHYTRIUM. 199 



the membrane thickens towards the outer surface especially, 

 and a cone-shaped growth of cellulose is formed. The proto- 

 plasm then takes on a more intense yellow green and divides 

 into numerous zoospores. Numerous bulgings of the plant cell 

 are produced probably by the growth of the surrounding tissues 

 of the host. An ostiole is formed at the apex of the cellulose 

 out-growth by which the zoospores escape. Those cells found 

 in the center of the host may attain as great a diameter as 275 

 mic. The even thickness of the wall of these cells suggests 

 that they may be resting stages. Kjellman refers this plant to 

 the genus Chlorochytrium, but hesitatingly on account of his 

 lack of knowledge about the further development. He found 

 C. inclusion in all of the Sarcophyllis edulis material which he 

 has examined. Zoospores are most abundantly produced in 

 winter, but are also found in summer. The endophyte occurs 

 in greatest abundance and most strongly developed in Sarco- 

 phyllis arctica. Its range is apparently coextensive with that of 

 Sarcophyllis arctica; i. <?., throughout the arctic region, except 

 in the North Atlantic, most abundant in the eastern part of the 

 Siberian sea. 



Three more new species were described by Schroeter in 1883. 

 Chlorochytrium rubrum with red contents and occupying the air 

 spaces of the leaves and stems of Pcplis portula and of Mentha 

 aquatica ; Chlorochytrium viride, in the leaves of Rumex obtus- 

 ifolius; and C. latum, a spherical cell with yellow contents 

 which become green in water, found in Lychnis jlos-cuculi. 



The investigations of Moore on Chlorochytrium lemna pub- 

 lished in the following year brought to light no new facts of 

 importance. Moore held that the nearest affinities of Chlorochy- 

 trium lie with Protomyces. 



In 1887 Hieronymus described C. archerianum in punctured 

 cells of Sphagnum leaves, and characterized by a greatly devel- 

 oped cellulose button. Zoospores are formed regularly but do 

 not copulate. P. Hariot, 1889, collected C. inclusum on species 

 of Gigartina at Cape Horn, supposedly identical with Kjell- 

 man's C, inclusum. 



In his Conspectus of Endophytic Algse, Mobius, 1891, men- 

 tions in addition to those species enumerated above, C. dermato- 

 colax which was described by Reinke and found on species of 

 Polysiphonia and Sphacelaria, and in his opinion should be 

 classified under the genus Chlorocystis, since it is marine, is in- 

 tracellular and emits zoospores singly. 



