DISEASES OF CONIFERS. 55 



apex of the leaves, which gradually extend downward to 

 the base, until they cover almost the entire surface. The 

 leaves finally become so diseased as to fall off, thus leaving 

 a long, bare branch, either completely destitute of foliage, 

 or occasionally with a small tuft of reddish-brown leaves 

 at the extremity. We have noticed that until very re- 

 cently, trees growing on low, damp grounds, where there 

 was imperfect drainage, were always attacked first. Es- 

 pecially was this the more clearly shown in nursery rows, 

 where we would observe a few trees standing in a spot 

 where, during winter particularly, there was stagnant wa- 

 ter about the roots, and whilst these trees would be gradu- 

 ally dying with this mysterious malady, others in the 

 adjoining rows would be perfectly free from its effects. 



Within the past year, however, this disease has become 

 less fastidious in its selection of situations, and has assum- 

 ed more of the character of an epidemic, spreading to 

 trees that were growing in soils exactly the opposite in 

 nature to the above. We have lately observed its appear- 

 ance on a number of Pinus Austriaca, and P. Laricio, 

 standing on a dry, gravelly hill-side, where the surface 

 had been washed away by the heavy rains. 



To these two extremes of unsuitable soils this disease is 

 almost entirely confined, and rarely can it be observed in 

 such pines as are growing in well prepared ground. 



After having examined and patiently studied this un- 

 healthy state of the tree, from the first intimation of dis- 

 ease through its various stages until death ensues, we are 

 obliged to admit that we cannot make any positive state- 

 ments in regard to its cause or eradication. In the disease 

 under consideration, small spots are perceived on the leaf 

 of the Pine, which spread rapidly until they cover the 

 whole surface. Under a good lens, these spots are discov- 

 ered to be a very minute fungoid plant, which, finding a 

 suitable condition for its growth, speedily destroys the 



