494 AMERICAN JOURNAL OF BOTANY [Vol. 8, 



at once to a pale amber. The boiled controls did not reduce the perman- 

 ganate. This is not necessarily indicative of enzyme action. The reduction 

 may be brought about by substances produced by the decomposition of 

 the pollen grains. 



Tests for Nuclease 



Tests for phosphoric acid, which might indicate the splitting of nucleic 

 acid, were made with ammonium molybdate on ground, un ground, germi- 

 nated, and boiled Easter lily pollen. All showed a strong phosphoric acid 

 test so that no conclusions could be drawn. 



Tests for Tyrosinase 



A solution of tyrosin gave a negative reaction for all pollens of the first 

 series tested. 



Tests for Laccase 



An alcoholic solution of gum guiacum, which Was rapidly colored blue 

 by freshly cut potato or orange peel, gave negative results with ten varieties 

 of pollen. 



Tests for Cytase 



i. The method given by Crabill and Reed was used. Filter paper is 

 dipped in manganese sulphate solution and then in potassium permanganate 

 solution. The resulting manganic oxid colors the paper dark brown. Acids 

 formed by the cellulose destruction combine with the manganic oxid to 

 form light-colored salts which show by contrast on the brown background. 

 Both ground and unground pollen placed on moistened sterilized strips of 

 such paper caused no color change, although a subsequent growth of mold 

 did so. 



2. Cellulose was prepared from filter paper in the following manner. 

 Schweitzer's reagent (ammoniacal cupric oxid) was used as a solvent. This 

 was made by adding to a strong copper sulphate solution, first, ammonium 

 chloride, and then an excess of sodium hydroxid. The blue-green precipitate 

 thus formed was allowed to settle, the liquid decanted off, and the precipitate 

 washed repeatedly with water on a Buchner funnel and filtered by suction. 

 The precipitate was then dissolved in 0.92 percent ammonia. The resulting 

 deep blue liquid readily dissolves strips of filter paper. When sufficient 

 paper had been dissolved to make a thick, syrupy liquid, it was poured into 

 dilute hydrochloric acid (1 : 5) and the cellulose was precipitated in small 

 flecks. The precipitated cellulose was washed repeatedly with water on a 

 Buchner funnel and filtered by suction, until the filtrate showed no trace 

 of HC1 when tested with AgN0 3 . The pure white mass of cellulose was 

 then boiled with distilled water to make a fine suspension and to sterilize it. 

 The suspension was tested with both iodine and Benedict's solution to be 

 sure that it was both starch- and sugar-free, as was the case. The tests 

 were made as follows: 10 cc. of cellulose suspension, 100 mg. of ground 



