EXPLANATION OF THE PLATES. 



PLATE I. 



FAC-SIMILE of the wood-engraving printed in Gerard's " Herb- 

 al," which is the first figure of this plant, and shows the general 

 characteristic of the plant at its introduction. 



PLATE II. 



FIG. 1. Diagram of the potatoe plant, to show its mode of 

 growth, particularly with respect to the formation of the tubers. 



a Original set. b Stem. c Collar. d Above ground stem. 



e Fruit. /Leaf. A Axil of the leaf. j Flower. 



k Under-ground, or tuber-bearing stem. These stems are given oft' chiefly in 

 two places, the upper one of which arises after the plant is earthed up, and shows 

 the utility of the process. 



I Tuber. 



TO Tuber growing from a former. This second tuber takes the starch from the 

 first (s), and renders it useless; and this continues to grow, taking the starch from 

 the further part of its own tuber, so that one end is good, the other worthless. 



n Above-ground stem growing from a tuber-bearing stem. 



o Tuber with roots, which is an unusual occurrence. 



r True roots of the plant. 



2'. Botrytis infestans, after Berkeley, showing the manner in 

 which it ramifies amongst the cellular tissue of the leaf. This 

 figure is highly magnified. 



PLATE III. 



FUNGI (Smee). 



All these are highly magnified. 



FIG. 1 . Fungi found on rotten potatoes, either on cut sections 

 or in cavities arising from the shrivelling of potatoes, or thrusting 

 up the cuticle, and thus appearing in great masses. 



