i6o 
S. Maugham. 
ON THE DETECTION OF MALTOSE IN THE TISSUES 
OF CERTAIN ANGIOSPERMS. 
By S. Mangham, B.A. 
Formerly Exhibitioner, Emmanuel College, Cambridge and 
University Frank Smart Student in Botany. 
[Figs. 1—4], 
N studying sugars from the point of view of plant physiology, 
certain practical difficulties are encountered which hinder 
progress in the knowledge of the parts played by these compounds 
in the vital activities of the plant. These difficulties are partly 
inherent in the nature of the investigations themselves, especially 
when these aim at determining by microchemical methods the 
nature and distribution of the sugars present in plant tissues under 
various conditions. 
The small size of a plant cell is a formidable obstacle to a 
satisfactory investigation of its contained sugar, and although the 
aid of a fine capillary tube has been invoked by some investigators 1 
to withdraw some of the contents of individual cells for subsequent 
examination, it is as a rule necessary to apply the test in use 
simultaneously to a number of cells, such as are contained in a 
section of the tissue. Needless to say satisfactory sections are not 
always readily obtainable. 
It has been customary to employ Fehling’s solution as a 
microchemical test for sugars in the tissues of plants. But this 
reagent has several disadvantages of which the more important are 
(1) that it does not give a precipitate with some of the sugars known 
to occur in plants, e.g., cane sugar, (2) that it also reacts with other 
bodies than sugars which may be present in the cells, e.g., tannin, 
and (3) that whatever the substance may be which reduces the 
solution, the resulting precipitate is always the same. Accordingly 
it is not possible by the mere application of Fehling’s solution to 
determine whether free sugar alone is present, still less to distinguish 
between the sugars which effect reduction. 
Apart from the inadequacy of the solution as a chemical reagent 
certain other disadvantages are met with in applying it practically. 
1 Stopes, M. C. C., and Fujii, K. “ The nutritive relations of the 
surrounding tissues to the Archegonia in Gymnosperms.” 
Bot. Centralbl., Beihefte XX., Abth. 1, 1906, p. 6. 
