206 



Table 9, TJie intensily of rn^dti plication of tlie green cliloropliyll 

 corpuscles of Spongilla in lighi^ when cultivated in sponge-tissue or 

 in loater in a weak or in a strong concentration of the corpuscles. 



Of a green Spongilla a i)iece was cultivated in an aquarium (p. 8 — 9), 

 while two cultures of green chloiophyll corpuscles in water were 

 made of the remaining parts (p. 9), one containing the corpluscles 

 in a weak concentration the other in a strong one. The sponge and 

 the cTÜtures were kept at about the same temperature. In all of them 

 the number of the stages of division per 100 green corpuscles was 

 daily examined — sometimes even several times a day — . A darker 

 green rim was soon formed in the cultures to the membrane on the 

 bottom (p. 40) — the usual way in which the multiplication of the 

 material is first recognized. Of course the chlorophyll corpuscles were 

 in a stronger concentration in tliis rim than somewhere else in the 

 membrane. 



In the tables is indicated : a. The date and the hour of the exami- 

 nation, h. The then stated number of the stages of division per 100 

 green corpuscles in the green sponge as well as in the cultures in 

 water, in tlie membrane and in the rim, in strong and in weak 

 concentration of the corpuscles ( — means no rim; -|- rim present). 



One day the concentration of the green corpuscles in the sponge 

 and in the cultures was closely examined and compared. As for the 

 method used, see p. 81. We shall call this concentration in a dark 

 green sponge or in a dark green membrane: strong (s.); that in a 

 yellow-green to light-green sponge or membrane: moderate (m.); and 

 that in a greenish sponge or membrane : weak (w.). 



From the tables results: 1 Periodicity in the multiplication does 

 not occur (p. 54). 2 The weaker the concentration of the corpuscles 

 present in a culture the higher is their intensity of multiplication 

 (p. 55). 3 In strong concentration the intensity of multiplication in 

 water and in sponge tissue are equal (p. 82). 4 The culture may be 

 destroyed quickly when infected by ])iY)tozoa (p. 79). 



