- 3 2 3 - 



4) Others, concerning whose precise significance we are not 

 fully informed, but which are probably largely not of first-class im 

 portance. 



" In the table below, the first two classes are grouped together 

 as severe and the last two as slight; the estimates of the severity 

 or leniency of the diseases are my own. 



" The dicotylous trees are infected by 15 severe fungal diseases, 

 of which 1 1 are limited to them, while the Coniferae are attacked 

 "by 25 severe fungal diseases, of which 21 are restricted to them; 

 the remaining 4 affect dicotyledons and Conifers. Of the 15 at- 

 tacking dicotyledons, 8 are wood-destroying Fungi that do not 

 infect coniferous wood; while of the 25 serious fungal foes of Co- 

 niferae only 6 are limited to wood (there are others attacking both 

 wood and cortex). As the Fungi attacking heartwood can hardly 

 loe regarded as of first-class severity, if they were excluded from 

 the lists the disparity between dicotyledons and Conifers would be 

 further increased." 



" Similarly, in regard to insect foes, I have drawn up lists of 

 the various insects attacking forest trees in Europe, using as the 

 source of information ' Lehrbuch der Forstinsektenkunde, ' by 

 Judeich and Nitsche: the results are given in the columns 2-7 of 



