LEAVES. 



67 



PLATE XXVII. 



FIG. 37. Powdered Hemlock Leaves (x 240). 



CO, Collenchymatous cells. 



eb, Epidermis of margin, strongly striated. 



ei, Lower epidermis, striated. 



en, Neural epidermis, striated. 



es, Upper epidermis, smooth. 



flV, Fragments of fibrovascular bundles. 



I, Bast. 



me, Spongy parenchyma. 



pa, p'a', Palisade cells. 



st, Stomata. 



tf , Cortical tissue of midrib. 



tr, Small vessels. 



