TASTE FUNCTIONS IN FISH 



229 



NH bands in addition to phosphate Unkage. The possible assignments of 

 the bands observed in the spectra of these gustatory active fractions are 

 shown in Table 2. From these analyses it seems most probable that the 

 gustatory active substance from the pupa which is soluble both in ethanol 



Table 2. Wavelengths of peak values from infrared 



absorption spectra for gustatory active fractions of 



human saliva and silkworm pupa extract. 



I : Ethanol soluble and ether insoluble fraction of pupa. 

 II : Ethanol soluble and ether insoluble fraction of saliva. 

 Ill : Ethanol soluble and ether soluble fraction of pupa. 



and in ether may be related to glycerophospholipid. Whereas the other 

 active substances which are ethanol soluble, but insoluble in ether, may be 

 sphingolipid-like, probably a mixture of sphingomyelin and glycolipid. 

 The spectrum from the ethanol soluble and acetone insoluble fraction of 

 pupa which possessed both ester C = and amide bands might indicate 

 that these fractions contain both glycerophospholipid and sphingolipid. 

 Although the gustatory active substance in the human saliva could not be 

 identified and further extensive analyses are necessary, it seems likely from 

 the infrared analysis of the ethanol soluble and ether insoluble fraction of 

 saliva that the activity might be exerted by certain lipid-like substances 

 which contain an amide group and probably also carbohydrates. According 



