150 JOURNAL OP THE ROYAL HORTICULTURAL SOCIETY. 



also a large number of as yet very obscure forms, such as 

 SiohcBrella, Stigmatea, &c,, &c. 



With regard to a large number of these forms, and to even 

 more numerous foreign forms, we are as yet quite in the dark 

 as to whether they are parasites or not. 



Experience warns us, however, that in many cases epidemic 

 fungus-diseases suddenly force themselves on our attention 

 owing to some form, hitherto occurring sparsely and known only 

 to the curious expert, having become suddenly favoured in its 

 struggle for existence. I have already given you several examples, 

 notably that of the Larch- disease, into the life-struggles of which 

 we have succeeded in peering rather deeply. Surely such con- 

 siderations should alone suffice to extend and cement that 

 sympathy between the practical horticulturist and the persistent, 

 though perhaps unobtrusive, investigator which, I am happy to 

 see, is becoming more and more pronounced as each understands 

 better the ways and high aims of the other. , 



It should be borne in mind, finally, that plant-diseases, like 

 human diseases, cannot be fully elucidated by a layman — though 

 it is astonishing how frequently the contrary assumption is acted 

 upon in the case of both. There seems to be a fatal temptation 

 in the idea of disease to the minds of most men, and the 

 response is dogmatism. 



INSECTS INJURIOUS TO CONIFERS. 



By Mr. W. F. H. Blandford, M.A., F.R.H.S., F.Z.S. 



Of all families of trees the Coniferre suffer most severely 

 from the attacks of insects, owing to the large number of species 

 which they support, and to the difficulty which, on account of 

 their physiological characteristics, they have in withstanding 

 injury. 



The wide area over which forests of these trees extend 

 increases the danger of insect-attacks, in accordance with a 

 well-known law which holds with injurious insects, and it is 



