550 THE PATHOGKNIC ALOAE. 



The zoospores (gametes) copulate in the gelatinous mass which 

 escapes, and break out from it as free swarming zygozoospores. 

 When the Lcmna falls to the bottom in autunni, or when it 

 dries up, the cells of the alga become resting-cells capable of 

 sustaining drought. Plants of Lcmna seem to be little 

 disturbed l)y attacks of the endophyte, and develop their 

 flowers normally. 



Chi. Knyanum Kirchn. i'requents Lcmna minor and Z. f/ihba, 

 CcratophyUvm demcrsum, Elodca canadensis, but not Lcmna 

 trisulca. It forms zoospores only, and these on penetrating 

 into a host do not produce a cellulose button like the species 

 just described. They appear to be able to enter the host only 

 by the stomata. 



Chi. pallidum Klebs. ({rows in the intercellular spaces of 

 Jjcmna tri^mlen. 



Chi. viride Schroet. Found in the respiratory cavity of 

 Kuniex oUiisifolins. 



(^ther species occur in dead Phanerogams or in Algae. 



Stomatochytrium limnan- 



^^^,^.^^,^ - themum Ounningh. Inhabits 



\ Jf f If the respiratory cavity of leaves 



** ^ ** ""^ of Limn anthem uni iiulicvm in 



India. 



Chlorocystis Cohnii Peinh. 

 Occurs as a "shelter-parasite " 

 Fio. 326.-.B»,(io.<ii)7.«f,Y- 6/f»r,i/.. in Po<awoj7e(oH j^^ marine algae. 



lucens. Cell of the Alga, which has peneti-atcd " 



?Aft"*^KMo^''^'^"'"*' ^ ^^'^ ^'^''^'* previously. Scotlnosphaera paradoxa 



Klebs. Found l)etweeii the 

 cells <tf dying lea^■es of Hypn^im and Lemna triscula. 



Endosphaera biennis Klebs. The zygozoospores have four 

 cilia, and swarm in water till they reach a living leaf of 

 Potamofjeton lucens. They generally come to rest on the under- 

 side of a leaf at the boundary wall between two cells, and 

 become invested in a membrane. A process is next sent in 

 between the epidermal cells, and all the cell-contents pass over 

 into it, the outer portion dying away. The young alga now 

 makes its way into the intercellular spaces of the sub-epidermal 

 tissue and becomes a resting spore. In spring this spore 

 gives off biciliate gametes, which, after copulating, become 

 zygozoospores. This shelter-parasite ha.s not yet been observed 



l*^^"^^ 





