RoSCIuhlJll: SVMPLOCARPUS AND LVSICIllTON. 149 



to the ground. Sometimes partly devoured fruits are left and in 

 these ways the seeds become scattered. 



Whether Syinplocarpiis is disseminated in the same manner 

 or not the writer is not prepared to say. It is very likely, how- 

 ever, that both genera have their seeds distributed chiefly by 

 rodents, such as squirrels and chipmunks, which in carrying the 

 fruits off to desirable places to eat them, drop an occasional seed, 

 or else store them away for future use and forget the hiding 

 place. 



It would seem that plants relying on such uncertain methods 

 of seed distribution must be extremely slow migrants and that 

 therefore it has taken these two aroids an enormous length of 

 time to come to occupy so wide a geographical area as they 

 do at the present day. 



The present geographical distribution of the two genera points 

 to an Asiatic origin and since the .Araceae are essentially a tropi- 

 cal family they must have originated somewhere in the eastern 

 tropics. From thence their course of migration was northeastward 

 into Japan, Kamtschatka, the Behring Straits region and across to 

 the American continent. Upon reaching America they wandered 

 south and east into their present areas. It is not likely that they 

 migrated simultaneously to America but rather that Symplocarpns 

 had a much earlier advent and gained a great eastward exten- 

 sion at a time when conditions for east and west migrations 

 were better than they became at subsequent periods. Ly sic hit on 

 appears to be a later immigrant and probably found the present 

 geographical and climatic barriers to limit its range. 



Summary and Conclusion. 



1. Upon germination the seeds of Symplocarpus and Ly- 

 sichiton produce 2-several scale leaves before foliage leaves appear. 

 The leaf arrangement is spiral and the rhizomes grow erect from 

 the outset. 



2. The rhizomes are sympodial in structure and are made 

 up of a very large number of renewal-shoots. They grow ver- 

 tically in the soil. 



3. Growth is extrem.ely slow so that only 3-7 mm. are 

 added each year to the top of the rhizomes. Large specimens 



