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/io Na2C03, 10 cc. pollen extract (50 mg. in 100 cc. 
distilled water, unheated and autoclaved), i mg. thymol in each tube. 
Kind of Pollen 
1. Apple 
2. Corn 
3. Daisy 
4. Dandelion 
5. Dock 
6. Elm 
7. Goldenrod .... 
8. Lily, Easter. . . 
9. Lily, tiger 
10. Pine, Austrian . 
11. Pine, white . . . . 
12. Ragweed 
13. Rye 
14. Timothy 
15. Magnolia 
16. Maple, Norway 
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, 
Hquid 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 cjiange 
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 Na2C03 added, but was positive without the addition of 
