No. 493] THE PHENOGAMOUS PARASITES 



The species which has been chosen to represent group 

 III is a European form and is quite distinct in certain 

 respects from even its nearest botanical kindred, and it 

 possesses habits that for variety and extent of abnor- 

 mality are not surpassed, and apparently not equalled, 

 by any other plant. It begins life normally, as do mem- 

 bers of group I, which it then closely resembles. The 

 presence of chlorophyl in the plumule of its plantlet and 

 the development of early rootlets seem to indicate an 

 honest destiny for the plant, but its subsequent acts al- 

 most suggest its utter abandonment to a groveling life. 



Group IV 



Seeds germinate upon the ground, producing an annual 

 herbaceous plant. Embryo filiform and coiled within a 

 mass of albumen in the seed; not differentiated into coty- 

 ledons, radicle or plumule. The resulting plantlet retains 

 the filiform structure of the embryo without differentia- 

 tion, except that the part which becomes the lower end of 

 the plantlet is slightly enlarged. As the embryo uncoils 

 the larger end enters the ground a little, but sends no 

 rootlets into the soil and therefore derives no true food- 

 sap therefrom. The smaller end points upward and the 

 plantlet elongates as a single thread-like stem until it 

 comes in contact with some freshly growing part of an- 

 other plant. It there attaches itself by quickly developed 

 haustoria, derives from the helpless host its first sufficient 

 nourishment, and becomes a branching vine. It then 

 reaches out for other hosts by more or less numerous 

 branches, and the part below the first haustorial attach- 

 ment quickly withers and dies. The branches grow rap- 

 idly and bear an abundance of flowers and seed. The 

 plant never naturally produces chlorophyl, and develops 

 neither true roots or functional foliage. The parasitism 

 is complete. Examples : Cuscuta of many American and 

 European species, and Cassytha of many Australian, New 

 Zealand and East Indian species. 



The members of groups I, II and III are all developed 

 from perfect embryos, like those of normal plants, their 



