AMERICAN 
JOURNAL OF BOTANY 
Vol. VIII December, 1921 No. 10 
POLLEN AND POLLEN ENZYMES 
Julia Bayies Baton 
(Received for publication March 28, 192 1) 
I. The Theoretical and Practical Aspects of the Occurrence of 
Pollen Enzymes 
Reasons for Undertaking the Investigation 
A review of the literature shows very few complete or satisfactory 
reports of experiments in regard to either the general chemistry or the 
enzymes of pollen. Our knowledge of the subject seems to be very frag- 
mentary. It is conspicuous by its omission from the textbooks of botany. 
Aside from, the few references given later, up to the present time no mention 
of any important work has been found. 
Although it is generally assumed, and is stated in our textbooks, that 
the pollen tube digests its way through the tissues of the pistil and the 
ovule, yet there seems to be no experimental evidence as to the exact nature 
of this enzyme action. Besides this, pollen enzymes must be very important 
in rendering the food stored in the grain available when the pollen ger- 
minates, in nourishing the tube during its passage through the style, and 
in stimulating the development of the embryo and the maturing of the 
ovary. 
Moreover, pollen anaphylaxis is now regarded as the cause of so-called 
hay fever and other forms of pollen poisoning. Pollen enzymes may be 
concerned in these reactions, and the proteolytic enzymes may affect the 
stability of the pollen-protein solutions used in pollen vaccination. 
In view, therefore, of the apparent meagerness of our knowledge of 
pollen enzymes and of the possible practical value of any contribution to 
this subject, it has seemed worth while to study the matter and to present 
the results. 
The Literature of Pollen Enzymes 
Few original, systematic experiments have been reported. Erlenmeyer 
(1874) found amylase, or diastase, in pine pollen. Van Tieghem (1869) 
reported inyertase, or invertin, in the pollen of hyacinth, narcissus, wall- 
flower, and violet. Czapek (1905, p. 393) quotes Strasburger's statement 
[The Journal for November (8: 425-470) was issued December 19, 1921.] 
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