67 

 green sponge in light: 



green sponge transferred into darkness 



T 



t 



light-green sponge in darkness : 



1 



colourless sponge in darkness: 



Now the reverse : proeeeding from a colourless sponge grown 

 in an aquarium in darkness (so : mu = mo). What happens when 

 we transfer this sponge into an aquarium in light? Then the 

 sponge will become green: 



colourless sponge in darkness : mu = mo 



A V 



colourless sponge transferred into light: mu > mo 



I ^ A II 



light-green sponge in light: mu > mo 



I 



green sponge in light : mu = mo 



I am not going to treat this question at large now, for I will 

 soon come back to it, when treating the behaviour of the sponges 

 in nature. 



^. 



Having examined the 6 factors, ruling the numher of sym- 

 biotic algae in sponge tissue, as well as some of their chief com- 

 hinations, we will trij to answer the ahove (p. 48) mentioned 

 questions, concerning Spongillidae in free nature, hij means of the 

 data we have obtaified in the mean time. 



1) < is stroBgei- than <, ^ is stronger thaa <. 



