71 



mil > e + g + ?wo (II). The balance is broken, the sponge keeps 

 more and more green algae, therefore becomes green itself. In 

 consequence of this increase of the concentration of green algae 

 the multiplication increases, the mortality, the import and the 

 reduction remain the same, but the export and certainly also the 

 factor of growth must increase little by little. The formula 

 i + r + mu > e + g -\-mo however remains binding (III). The end 

 of this process must be, that the sponge lodges an excess of green 

 algae in its tissues, it therefore becomes dark-green itself; even 

 there would not seem to come an end to the increase of the 

 number of green algae in this way. That is impossible, of course; 

 in such a dark-green sponge the factors must change in such a 

 way, that at last this perpetual increase ceases. This changing 

 is again the consequence of this great increase of concentration 

 of the green algae : although the multiplication has still increased — 

 it is considerable and much more intensive than in the beginning 

 (Table 10) — and the mortality has remained the same — it 

 is moderate and much lower than in the beginning (pag. 59) — , 

 the factors of growth and export have certainly strongly increased, 

 while the import has remained the same (rather considerable) as 

 well as the reduction (= 0). In this way a new balance i^r-\- mu 

 z= e -\- g + mo must arise in the dark-green sponge in light (IV) — 

 of course another than the originally existing one. 



We may again symbolize the transition mentioned, in the fol- 

 lowing way : 



(I) colourless sponge in darkness : ^ + /• + mu = e -{- g -{- mo 



II II 'a II II V 

 (II) colourless sponge transported into light: ^ + r + mu > e ->r g -{- mo 

 I II II A A A A II 



(III) light-green sponge in light : ^ + r + mu > e + g -\- mo 



Ï II II A A A II 



(IV) green sponge in light : i -\- r + mu = e -\- g -\- mo 



II 

 



