THE BARLEY-CORN. 
225 
the study of the development of the barley-corn; otherwise the 
interpretation of the histology would be very difficult, indeed 
wellnigh impossible. 
The first figure is that of a longitudinal section taken in the 
middle plane of the barley-corn. On account of the difficulty of 
cutting the indurated pericarp and paleae, these have been for 
the greater part removed, although a few fragments remained 
attached. The general topography of the grain can, however, be 
seen. By far the greater part of the whole volume is occupied 
Fig. 41. Longitudinal section through the part of the barley grain which 
includes the embryo and a small portion of the endosperm. PI., plumule; 
Scu., scutellum. The main root, with its root-cap, is seen within the root- 
sheath. Above it a portion of one of the lateral roots. The right-hand 
leader from Scu. points at the scutellar epithelium. 
by a mass of tissue, the endosperm, in which are stored up 
various food materials—starch, oil, proteids—to be used by the 
sprouting plantlet. In the figure only a little of the endosperm 
