(395) 



usually of great length, the outer portions of which swell in moisture 

 and become gelatinized to form a jelly-like matrix in which the 

 spores appear imbedded. Of further interest in connection with 

 the telial stage are the characteristic swellings and galls which 

 are produced by many of the species. 



Comparison with Other Rust-Genera 



Several other uredineal genera, Coleosporium, Melampsoropsis, 



Pucciniastrum, Melampsorella, Melampsoridium, and Cronartium, 



are known to have their antithetic phases inhabiting dicotyledon- 



Anglosperm host 



Gymnosperm host 



the angiosperms bear the telia and the gymnosperms the aecia, 

 but the order in Gymno sporangium is just the reverse. It is the 

 only genus having this reverse order and as might be expected the 

 reversal in the sequence of hosts is accompanied by a new departure 

 in the physiological functions of the spores. In the genera men- 

 tioned above, Coleosporium, Melampsoropsis, etc., the teliospores, 



