of LathrcEa Squamaria, SfC. 419 



EXPLANATION OF THE PLATES. 



Tab. XXIL 



Fig. 1. An embryo plant: a, the natural size; b and c, highly 

 magnified in different positions. 



2. An entire plant, showing the large tubers on the caudex 



of the root at b; the small ones on the fibres, and a 

 young abortive flower-stem, c, in its progress towards 

 the surface of the soil. 



3. Portion of a subterranean stem with its tuberiferous 



fibres, and a portion of an Ash-root with some of the 

 tubers fixed upon it. a. Wounds in the bark caused 

 by old decayed tubers. 



4. Longitudinal section of part of the caudex and one of 



its large tubers magnified, showing its complex system 

 of vessels ; some of which, towards the base, a, are 

 cut through transversely. 



5. Portion of a fibre with a young tuber before its attach- 



ment ; and another torn from the bark, showing the 

 lacerated edge of the cuticle and the reticulated por- 

 tion in contact with the bark. The dark central spot 

 is the branching off of the exhausting vessels : — highly 

 magnified. 



Tab. XXIIL 



Fig. 1. Perpendicular section of a tuber cut across its fibre, 

 showing its beaded system of vessels, the insertion of 

 its tap-shaped base into the alburnum, and the bor- 

 der of new liber formed round the cavities to stop the 

 progress of the diseased parts, a. Section of the con- 

 necting fibre. 

 2. Ditto, ditto, in the direction of its fibre. - • 



JFV^. 3. 



