CHEMOTROPIS.M. 65 



infesting the fatty matter of insects. This faculty uiay be 

 regarded as non-essential to such fungi as make their habitiit on 

 oilcake (§ 2^5) and consume thn fat therein, since — as has het-n 

 shown, particularly V>y W. 8it;Mi nd (I ) — the oil .seeds freijiit-ntly 

 contain lipase, and it is very probable that some portion of this 

 is left behind in the oilcake. It is. however, doubtful whether 

 this residue has n«jt alieady lo.st its jKjwer, and is consequently 

 incapable of being utili.sed by the infesting orgauism.s, the 

 lipases being very sen.sitive to injurious intiuences (acids, salts, 

 iVrc.) For this rea.son, it may be remarked in pa.ssing, all 

 attempts at their i.solation in a pure state have faile<l. The 

 cjipacity of producing fat-decomposing enzymes is certiiinly 

 posses.sed by the fungi which, within a few months, reduce the 

 fat content in the mu<l of .settling tjinks in waste-water 

 pui'ifying plant, from over 20 per cent, to almost nil. Sundry 

 highly instructive experiments on this point have been 

 conducted by J. Becuold (I.). 



With regard to the various enzymes of yeast in jiarticular, 

 full details will be given in a later section. 



VOL. n. 



