SIPHONED. 



VAUCHERIA SESSILIS, Vauch. 



I. This Alga is to be found growing as a lax green 

 felt on the surface of moist soil (frequently on the soil 

 in pots in greenhouses) : it is of so coarse texture that 

 the separate filaments can readily be recognised with 

 the naked eye, having a somewhat dull, green, glassy 

 appearance. Remove a small portion of this felt : tease 

 it out as gently as possible in water, and examine it 

 under a low power : observe 



1. The coarse, green, cylindrical tubes which con- 

 stitute this Alga. 



2. The absence of septa as a rule, though septa may 

 be present occasionally in unhealthy specimens, and are 

 formed in connexion with the reproductive processes. 



3. The very irregular, and far from frequent, mono- 

 podial branching, and the rounded ends of the 

 filaments. 



4. Some branches may develop as rhizoids, rami- 

 fying in the soil, but these are frequently absent 

 altogether. 



5. There may be present lateral outgrowths of 



