210 VEGETABLE PHYSIOLOGY 
their hosts. The most easily observed of these is the 
Dodder (Cuscuta), which often attacks the cow-wheat or the 
Fria. 102,—Srorton or Stem or DicoryLrponovus PLANT ATTACKED BY 
Havustonia oF Cuseuta. 
clover (fig. 101). The seed when germinating puts out an 
embryo which has no cotyledons. Germination takes 
