460 



Journal of Agricultural Research 



Vol. I, No. 6 



Norway pine (Pinus resinosa), which is regarded as a hard or pitch pine, 

 offers an exception to this. Here we find numerous tyloses, but here 

 also we have large ray pits. The only soft pine examined which did not 

 contain tyloses was pifion pine (Pinus edulis). This species is character- 

 ized by small ray pits instead of the large ones common to this group. 



Of the other conifers all of the species listed below have small ray pits. 

 No true tyloses were found in these species. (See Table III.) 



HI. Occurrence of true tyloses in native conifers. 

 SOFT PINES. 



HARD PINES. 



