CY STOP US CANDID US. 49 



protoplasm by means of a fertilizing tube, and the 

 subsequent formation of a thick-walled resting spore is 

 very similar to what takes place in Spirogyra. In both 

 cases the spore clothes itself with a thin inner wall, 

 very difficult to see clearly, and an outer, thick pro- 

 tective wall. In Cystopus this outer wall is sculptured 

 in a manner characteristic of the species. The oospores 

 thus formed remain over winter ; the tissues in which 

 they lie become disintegrated ; they are distributed by 

 rain' and wind, and finally germinate. 



Next to the mode of sexual reproduction, the most 

 interesting feature about the plant under consideration 

 is its habit of life and the adaptations which have been 

 induced thereby. It is throughout its existence a 

 complete parasite, growing and feeding upon plants of 

 a very high degree of organization. Being no longer 

 required to elaborate food for itself, finding it always 

 at hand and of superior quality, it possesses no chlo- 

 rophyll bodies by which it might assimilate its own 

 food, and is therefore quite colorless. As it grows, 

 it sends its branching filaments ramifying throughout 

 all the softer tissues of the host. They do not 

 penetrate the cells, however, but push about between 

 them, and in order to extract the nourishing fluids 

 readily, especially in the newest portions where rapid 

 growth is taking place, send out sucking tubes or 

 haustoria, which penetrating the adjacent cells expand 

 into minute absorbing bulbs. 



The means of distribution which the plant possesses 

 in its oospores is rather limited, being inferior to that 

 of Spirogyra ; and when once established in a host it 

 is debarred from all further locomotion, such as the 



