91 



lose. However, carbohydrato (glucose) will probably be furmed 

 (but theii kept in solution); so also Oltmanns (47) gives for 

 some algao that, although oil may bc found as final product, 

 tlic prime products of photosynthesis are probably carbohydrates; 

 also see Pfeffer (47 a) for plants in general. 



13. The amoebocytes of green and colourless Spoiigillidae and 

 their gcmmules show, when stained by I in KI sol., numbers 

 of very sniall red-brown globules, much smaller than the oil- 

 droplets (Table 14) and especially situated along (the inside of) the 

 wall. On the other hand I have never found vacuoles stained by 

 I in the amoebocytes, as Lankester (35) states. One will be 

 inclined now to consider these small brown globules as a solid 

 carbohydrate ; but such a colouring by I does not yet give suffi- 

 ciënt proof by itself. So I have also tried to prove in a more 

 direct way, that carbohydrates occur in the sponge tissue. And 

 such with the help of tlie Fehling solution which, as known, 

 gives a red precipitation, when boiled with a reducing sugar (for 

 instance glucose or an other monosaccharide). 



I rubbed a green Spongilla, just boiled the remaining fluid and 

 filtered it, while the symbiotic algae and all smaller particles 

 passed through the filter. The fluid reacted neutrally and was 

 light-green, rather troubled. This liquid, now, showed after having 

 been boiled with some Fehling solution rather a considerable 

 red precipitation, while a blind experiment (Fehling boiled 

 without sponge liquid) did not show any reduction. So sugar 

 (probably a monosaccharide) was present in the sponge. Next the 

 same was repeated with sponge liquid, which had in advance 

 been boiled for one hour with some drops of strong HCl 

 (to break down polysaccharides which might be present), then 

 neutralised by KOH and filtered; this liquid showed strenger 

 Fehling reduction than the original one. From this we may con- 

 clude, that the sponge liquid, consequently the sponge tissue, con- 

 tained a polysaccharide besides the monosaccharide. But this poly- 

 saccharide need not exactly have been the carbohydrate which can 

 be stained by I; it may have been exclusively the cellulose of 

 the algal cell-walls (perhaps the increased reduction after hydro- 



