74 MICROSCOPICAL RESEARCH 



PLATE II. 



BOOT STEUCTTTEE. 



Fig. 5. Transverse section through radical end of a grain of harley., 

 after twelve hours' germination. Fixed with Chromo- 

 Acetic solution. Cut 1/ 1500 in- Stained with Brazilin. 

 1. Aleurone layer. 2. Endosperm, containing starch. 

 3. The pericarp. 4. Primary nucleated tissue of scutellum. 

 5. Cells to form epidermis (dermatogen). 6. Cells to form 

 cortical tissue (periblem). 7. Cells to form vascular system 

 (plerome). 8. Central vessel of root. 9. Absorptive layer of 

 embryo. A. The four lateral roots. B. The primary or 

 tap-root. 



Fig. 6. Entire plant of 'Lemna minor,' common Duckweed x 12dia. 

 Fixed with Chromo-Acetic solution. 1. The fronds contain- 

 ing bundles of raphides (shown as dark spots). 2. Eoot. 

 3. Eoot-cap. 4. Developing root. 



