STIMULATION. AND ITS RESULTS 389 
in the protoplasm of the cells on the lower sides of its 
Fic. 158.—Srecrion oF Stem or DicoTyLEDONOUS PLANT ATTACKED BY 
Havstoria or Cuscuta. 
into the intercellular spaces between them. It is attended 
by a change of colour, the -pulvinus becoming of a deeper 
