388 Collins .— The Structure of the Integumentary System of the 
(d) Extent of the cuticularized membranes. (See Figs. 3 and 4.) 
The examination of sections cut at different levels between the basal 
and apical ends of the grain showed that the cuticularized membranes 
were continuous around the greater part of the grain. The two membranes 
of the tegmen end in the group of cells in the region of the furrow (see 
Fig. 2). Sections across the basal end retaining the membranes in position 
were not easy to secure, so that it was not possible to determine precisely 
now far the membranes were complete in this region. 
Sections of the immature ovule, examined after treatment with 
Scharlach R., showed that the tegmen 
FlG 3. Diagram of the solid grain with paleae 
removed. 
membranes were cuticularized even 
Fig. 4. Diagram of transverse sections of germinal 
end of barley grain: A. just above, B just below, the 
scutellar rim on the furrow side. 
at the earliest stages of development. By means of such sections it was 
proved that the membranes completely envelop the ovule, with the 
exception of the micropyle and the chalazal tract itself. In longitudinal 
sections of the mature grain the micropylar point was not satisfactorily 
made out, although the membranes could be traced up to a dark-coloured 
cap-like covering, to which was attached the embryonic appendage. 
Protected as it is by the pericarp and paleae, the cuticularization 
of the tegmen is at once an interesting and suggestive feature in the 
morphology and biology of the coverings, but for the immediate purpose of 
this research its physiological significance is in the foreground. 
