PLATE 27 



160 







163 



162 - V 



164 



166 



160. Ipomoea coccinea. Section of upper epidermis at base of mature leaf ; over a vein, showing long papillae along veins. 



161. Ipomoea quamoclil. The same, showing no papillae over veins. 



162. Ipomoea sloteri. The same, showing smaller papillae along vein and that the stomata are slightly more 



numerous at the veins. 



163. Ipomoea coccinea. Section of epidermis at base of filament showing short glandular shaggy hairs. 



164. Ipomoea quamoclil. The same, showing much longer glandular shaggy hairs. 



165. Ipomoea sloleri. The same, showing glandular shaggy hairs of intermediate length. 



