163 



Tf one examines a normallij living prepm-ation of sponge tissue 

 that ' remains in carmine suspension for soms hours, one will find 

 carmino, as has been mentioned on p. 146 and 149 — 150, on the 

 one side in a great quantity in the choanocytic layer of the flagelr 

 lated chambers (Fig. 6G, 71) and on the other side also in a 

 great quantity in an apparently undifferentiated plasmic substance 

 (in which few or no symbiotic algae) in the walls of the canals — 

 to which it will have been transported, for instance, after having 

 been captured in the plasmic layer at the outside of the flagellated 

 chambers (p. 152, Fig. 75). 2'>J. If then the preparation is in pure 

 water for*some time, we find, as we saw on p. 146 — 148, hardly 

 any carmine in the choanoeytes ; but it now appears to be in 

 small conglomerates within the amoebocytes with symbiotic algae. 

 Besides we also find it in large conglomerates (upto 17 jot), and some- 

 times together with detritus, within vacuoles in the apparently 

 undifferentiated plasmic substance (in which few or no symbiotic 

 algae) situated along the canal walls. 3"i. The sponge having heen 

 in pure tvater for soine time longer, the carmine also disappears 

 from the amoebocytes ivith symbiotic algae, to he found almost only 

 as large conglomerates in an apparently undifferentiated plasmic 

 substance (in which few or no symbiotic algae) and mostly situated 

 along the canal walls and often together with detritus within a 

 vacuole (Fig. 76a, 77). 



One will have to acknowledge that these observations on living 

 tissue correspond very well with the results obtained in ravel 

 preparations. The matter now ivas to observe the phenomenon of 

 the ejecting of feces itself. 



In this too I succeeded in my normally living preparations. 

 But also here I had to exert much patience. 



I shall now give a description of such a phenomenon of defeca- 

 tion, as I observed it on a preparation which, after having been 

 in carmine suspension, was in pure water for some time: A car- 

 mine conglomerate lies, together with some detritus and some 

 green symbiotic algae, along the wall of a canal in the 

 often mentioned apparently undifferentiated plasmic substance. 

 At first no vacuole is to be seen round these parts, but shortly 



