Freeman : OBSERVATIONS ON CHLOROCHYTRIUM. 203 



observation was collected, on the other hand, in summer, May 

 to July. The light yellow-green color, the absence of repro- 

 ductive bodies and the abundance of small cells point strongly, 

 I think, to the conclusion that this endophyte is but a young 

 stage of Chlorochytrium inclusum Kjellman. A similar dif- 

 ference in the vegetative and resting stages of C. lemnce are 

 recorded in Klebs' observations (pi. 39, f. 2 and p). The 

 form and habit of the endophyte upon Constantinea accord 

 best with Kjellman's description of C. inclusum\ no mention, 

 however, is made by Kjellman of pyrenoids, which are so 

 conspicuous in the Constantinea material. It is suggested by 

 De-Toni and also by Miss Whitting that Kjellman's species 

 may possibly belong to Chlorocystis, a genus established by 

 Reinhard in 1885. Chlorocystis is described with but one 

 pyrenoid while the endophyte on Constantinea contains many. 

 C. schmitzii, described by Rosenvinge, is but imperfectly 

 known. I have seen in the sections studied a number of cases 

 where the endophyte in Constantinea has assumed approxi- 

 mately the same irregular or obovoidal form shown in the 

 figures of Rosenvinge. The only remaining marine species 

 of Chlorochytrium, C. dermatocolax, lives in the outer mem- 

 brane of Polysiphonia and, according to Mobius, belongs prob- 

 ably to Chlorocystis. 



The great similarity in vegetative structure to that described 

 by Kjellman for C. inclusum would indicate that the Constan- 

 tinea endophyte described above is a midsummer stage of C. 

 inchisum and I would provisionally place it in that species 

 awaiting further information on the life history and develop- 

 ment. 



BIBLIOGRAPHY. 



Cohn, F. Ueber parasitische Algen. Remarks before the " Wand- 

 erversammlung der Schlesischen Gesellschaft fur vaterlandischer Cul- 

 tur. Botanische Section. 1872. Beit, zur Biologic der Pflanzen. 

 I 1 : 87. pi. 2. 1875. 



Kny, L. Ueber eine griine parasitische Alge. Sitz. Gesellch. na- 

 ttirf. Freunde zu Berlin. 1874. 



Wright, P. On a new species of parasitic green alga belonging to 

 the genus Chlorochytrium of Cohn. Trans. Roy. Irish Acad. 26: 1877. 



Szymanski, F. Ueber einige parasitische Algen. Inaug. dissert- 

 der Univ. Breslau. 1878. 



Kirchner, O. Die Algen Schlesiens. Breslau. 1878. 



Klebs, G. Beitrage zur Kenntniss niederer Algenformen Bot. 

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