112 PRINGSHEIM, ON CHRONIZOOSPOllES OF HYDUODICTYON. 



alsOj in becoming detached, to allow the spores more space 

 for, and greater freedom in their movements. 



When on the contrary, as in Ulothrix and certain branches 

 of Draparnaldia, the fertile cells remain closed, one cannot 

 think that the spore has ever been endowed with motile 

 power ; for it has fulfilled all the phases of its development, 

 strictly enclosed within the walls of the parent-cell. 



I shall not now djscuss, though I may recur to the subject 

 at a future time, whether the slight differences or modifica- 

 tions which are observed in the formation of hypnospores in 

 the Draparnaldia, betoken germs of unequal morphological 

 value, or, whether the same relation exists between them as in 

 the Hydrodictyecie,is found between the spores oiHydrodictyon 

 and Pediashim on the one hand, and those of Ccelastnim on 

 the other ; and whether, if in the Draparnaldise, chronizoo- 

 spores co-exist with spores of equal dignity, but motionless 

 from their origin, that is to say, chronispores properly so 

 called. 



It was sufficient for the object of this notice to show in the 

 mode of existence of the spores oi Draparnaldia glomerata, a 

 second and very precise example of zoospores passing into the 

 state of chronispores. 



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