24 



PROTESTS AND DISEASE 



tube, simple or branched, at first without septa. It is 

 usually sparsely branched and some of the branches may 

 be modified into rhizoids, Fig. 3, B, r. The protoplasm 

 lines the cell- wall and contains nuclei in its inner layer, and 



Fid. 3. SOME ALGAE AND FUNGI. A, diagram of a filamentous alga; 

 ma, macro-, mi, microzoospores ; B, Vaucheria ; r, rhizoid ; z, zoo- 

 gonidium ; a, antheridium ; o, oogonium ; C, end of a hypha of 

 Achlya ; sp, spores ; a, antheridium ; o, oogonium ; os, oospores ; 

 D, end of a Saprolegnia filament infected by Rozella septigena ; E, 

 later stage of an infected hypha ; ps, parasitic segment ; o, o, openings 

 whence zoospores have escaped ; rs, resting spores of Rozella ; c-d, 

 after de Bary and M. Cornu. 



chlorophyll corpuscles and oil-drops externally. The middle 

 of the filament is occupied by a sap-vacuole. 



This arrangement, a multinucleate non-septate con- 

 dition seen in Siphoneae, is also found in Phycomycetes 



