SCIENCE-GOSSIP. 



201 



AN INHABITANT OF VAUCHERIA. 

 By J. Lewton Brain. 



QEVEKAL weeks ago I collected some specimens 

 of freshwater algae in the River Wensum. 

 Days elapsed before I was able to examine them. 

 On doing so, I was struck with the (comparatively) 

 enormous size of what I took to be the sexual 

 organs of a species of Vaucheria. Further search, 

 however, revealed the fact that they were not 

 sexual organs at all, but abnormal expansions of 

 the thallus. Examination at intervals forced upon 

 my notice a dark brown moving speck in some of 

 them, and I conjectured that some stray rotifers or 

 cyclops, or such like, had made their way into the 

 interior and set up a sort of irritation, and caused 

 the protuberances, or their enlargement. My 

 curiosity was by this time fully aroused, and I 

 devoted a spare Saturday to a thorough examina- 



tion of the material, of which, happily, I had a 

 fair amount. The result was that I became 

 convinced that it was no stray individual or so, but 

 that a populous colony of rotifers had annexed the 

 Vaucheria for the purpose of laying their eggs and 

 securing protection for their young. As this was 

 all quite new to me, I made some rough drawings 

 and sent them with some of the material to the 

 Editor, asking him to name the rotifer, and offering 

 to write a short description of my find. This offer 

 he has been good enough to accept, but the rotifer 

 (if it be one) is still anonymous. 



The alga is V.geminata ; in some cases the sexual 

 organs could be made out. The first indication of 

 anything out of the common is a globular swelling 

 of the thallus (fig. i). At this stage I have not 



ExcRKSCKNCES ON VAUCHERIA AND THEIR INHABITANTS. 



