Suberin and Cutin 
17 
SUBERIN AND CUTIN 
By J. H. PRIESTLEY 
Introduction 
D uring an investigation of the physiological role of the endo- 
dermis it became necessary to describe the composition of the 
radial and transverse walls of this tissue, which from an early stage 
in their differentiation appear relatively impermeable to water. The 
impermeability to water of a plant membrane seems usually to have 
been ascribed to the presence within it of suberin or cutin, but in 
using these terms the writer was very conscious of the lack of pre¬ 
cision with which he employed them. Reference to current English 
text-books revealed a similar vagueness even in the most recent 
monographs on plant biochemistry. However, a search through the 
literature showed, that during the last thirty years a great deal of 
light had been thrown upon the subject by the research of different 
continental investigators. The work seems so important and so neg¬ 
lected in this country that it is proposed to give a brief account of 
it in this paper. 
Although this is a review of earlier work upon the subject, no 
lengthy bibliographical record is attempted, but reference to the 
papers cited will enable any reader to obtain the nucleus of an excel¬ 
lent bibliography. On the biochemical side Czapek’s book( 4 ), p. 695, 
contains a very valuable chronological summary. Here it is only 
possible to emphasise the most salient points in the development of 
our knowledge of the subject. 
Most of our knowledge refers to suberin which is available for 
study in convenient form in the shape of bottle cork, the but little 
altered periderm of Quercus suber. Cutin receives elucidation usually 
indirectly as result of the work done upon suberin. So far, those 
substances are rather distinguished by their position in the plant, 
than by their properties, suberin being formed in the periderm, cutin 
in the outermost layer of many epidermal walls which are thus 
provided with a cuticle. 
It will be seen from the account which follows that suberin and 
cutin, although still far from completely known, are names for aggre¬ 
gates of substance occurring in or on plant membranes and differing 
in their composition as well as in their distribution in the plant. The 
component substances of these aggregates have to some extent been 
9 
