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SCIENCE PROGRESS 



however, that for a short period during its life-cycle, Chlorococcum 

 affords us the first example of the coenocytic habit, paramount 

 throughout the series of the Siphonales. This incipient cceno- 

 cytism is found in all the different members of the Proto- 

 coccaceae, which can, however, only be dealt with very briefly 

 (Klebs 37). The genus Chlorochytrium is nothing more than 

 a Chlorococcum which has become modified as a space-parasite, 



Fig. 3. 



a, Chlorococcum limicolum (Beyerinck), Oltmanns (liberating zoospores). b, PhyUohivm dbnorphtim, 

 Klebs. c, Chlorosphcprci consociata, Klebs. D, Pediastrum Boryanum (Turp.), Menegh. k, Proto. 

 siphon botryoides (Kiitz.), Klebs. F, Valonia utricularis (Roth.), Ag. G, Cladophora spec, (small 

 portion of a filament). H, L, Vancheria piloboloides, Thur. (aplanospores). K, Vancheria repens, 

 Hass. (zoospore). M, Dichotomosiphon tuberosus (A. Br.), Ernst, (with gemmae), (a after Beyerinck ; 

 B and E after Klebs ; c after Artari ; D after A. Braun ; F after Schmitz ; G after Oltmanns ; H, L and 

 m after Ernst ; K after Goetz). 



the large resting-cells of the different species occupying the 

 intercellular spaces of diverse higher plants. It is possible 

 that the Chlorochytrium receives nitrogenous compounds from 

 its host, for the species of Chlorococcum and other allied genera 

 have the faculty of making use of organic nitrogen, and often 

 abound, as a consequence, in putrid solutions, avoided by 



