Dec, 1921] 



PAT ON — POLLEN AND POLLEN ENZYMES 



491 



to 5-cc. portions were added 5 cc. of distilled water and 100 mg. of pollen. 

 For the control the pollen and water were first autoclaved. The tubes 

 were incubated at 37 ° C. for 24 hours or longer (see table 13). The tubes 

 were taken from the incubator and placed simultaneously in ice water, and 

 the failure to solidify, or degree of congealing, during 10 minutes was noted. 

 Many investigators have used gelatin for detecting enzymes of the 

 pepsin type, but the experiments of Malfitano, Mavrofannis, and Jordan, 

 recently confirmed by Berman and Rettger, seem to indicate that lique- 

 faction of gelatin by an organism is not proof of proteolytic activity. How- 

 ever, since pollen extracts, like pineapple juice, possess this power of lique- 

 faction to a marked degree it has been considered worth while to record the 

 observations. 



Tests for Trypsin 



Table 14 



Congo red, blood fibrin, 2 cc. N/10 Na 2 C0 3 , 10 cc. pollen extract (50 mg. in 100 cc. 

 distilled water, unheated and autoclaved), I mg. thymol in each tube. 



Appearance of Solutions 



Unheated 



No change 



Fibers disintegrated. 



Liquid very pink 

 No change 



Fibers less firm. 



Liquid pinkish 

 Liquid faint pink 

 Fibers disappeared. 



Liquid red-brown 

 No change 



Fibers partly disinte- 

 grated, liquid pink 



Fibers partly disinte- 

 grated, liquid pink 



Fibers partly disinte- 

 grated, liquid pink 



Fibers partly disinte- 

 grated, liquid pink 



Fibers partly disinte- 

 grated, liquid pink 



Fibers disintegrated, 

 liquid pink 



No change 



Autoclaved 



No change 

 Fibers unaltered 

 Liquid pale, yellow 

 No change 



No change 



Fibers unaltered 

 Liquid yellow-brown 

 No change 



No change 

 No change 

 No change 

 No change 

 No change 

 No change 



From tables 14-16 it may be seen that corn, goldenrod, Austrian pine, 

 white pine, ragweed, rye, and timothy all gave positive results. Dock gave 

 strongly positive results in the less alkaline medium, while magnolia and 

 goldenrod were strongly positive in the more alkaline medium. Apple was 

 negative with Na 2 C0 3 added, but was positive without the addition of 



