110 



water? Sliould one not rather suppose, that by this circulation 

 the necessary quantity of 0.^ will already be kept up sufficiently 

 in the tissues of the sponge in darkness, though it will be lower 

 than in the green sponge in light — perhaps the green sponge 

 in light wil not do anything with its larger quantity of 0^ and 

 simply let it slip — ? If this were not the case, liow would 

 then be the course of that katabolic phase in all higher water 

 organisms not lodging chlorophyll, when lack of light ah*eady 

 changed it so enormously in Spongillae (that is to say, made 

 it go on accompanied with freeing of but relatively little energy). 

 One then had to come to the conclusion, that all these higher 

 water organisms, not lodging chlorophyll, can only produce less 

 complete oxidations in their katabolic phase of metabolism (that 

 is to say, less complete than the green Spongillae in light). 



On the ether side one has to acknowledge that it is diffi- 

 cult to imagine, that this large quantity of 0^, which is present 

 in the tissues of a green sponge iu light — I just remind that, 

 according to p. 18 «, green Spongillae in sunlight even develop 

 gasbubbles (very likely of O^) — would have no considerable 

 influence on the katabolic phase of metabolism of the sponge, 

 Besides, ^how would otherwise the phenomena, mentioned on p. 

 108^ /3, have to be explained? ') 



But let us leave now this question about the lack of O2 (with 

 all its consequences) in the tissues of a sponge in darkness. It 

 cannot be dissolved before we have stated experimentally, if in 

 fact Spongillae in darkness excrete less complete oxidated products 

 of metabolism than green sponges in light. Certainly this question 

 would be worth such a research ! I hope to be able to do this 

 afterwards. 



Also the question which was our starting point on p. 106, 

 namely : whicli in fact are the exact causes of the dying of the 

 algae in the amoebocytes, must, as said before, wait for its de- 

 cision. The best thing is that, for the present, we content our- 



]) And how (sce p. 51 noto) the perhaps smaller „filtering power" of a (colourless) 

 sponge in dark? 



