CRYPTOGAMIC PLANTS INJURIOUS TO FOREST TREES. 251 



and much more by guarding against those conditions and contin- 

 gencies which induce disease in plant organisms. 



To return to the subject for discussion, we know that many of 

 the numerous genera of cryptogams are more or less injurious to 

 plant life, and one very important class of diseases amongst trees 

 and timber arises from the attacks of parasitic fungi. To illus- 

 trate the dangers arising from the attacks of fungi upon trees, I 

 will describe an instance or two which have come under my own 

 notice of the fatal injuries inflicted by them, and which, I hope, 

 may interest the meeting and promote discussion as to the nature 

 and amount of the damage perpetrated by them upon forest trees, 

 and the best methods that are known and available for their pre- 

 vention or cure. I will first describe a notable instance of a seri- 

 ous attack of fungus upon some fine young trees of Welling- 

 tonia gigantea, which were under my care in the year 1865, 

 and the plan I adopted to remedy the evil. In the summer 

 of that year a row of about twenty Wellingtonias, which were 

 growing in a light loamy soil, on an open, dry, gravelly subsoil, in 

 a moderately well sheltered situation, began to show immistakable 

 signs of failing health, and upon examining the roots I found 

 them to be completely swathed in the mycelium or spawn of a 

 fungus, which had worked its way under the bark of the roots and 

 stem in several of the trees, so as to completely choke up the 

 alburnum or sap-wood, rupturing its tissue, and entirely pre- 

 venting the circulation of the sap, and theixby causing the death 

 of the tree. From this cause two of the trees were killed outright 

 before the end of August ; and another was so badly infested with 

 the spawn, and so ruptured and injured at the base of the stem, 

 that I considered its recovery hopeless, and therefore destroyed it. 



When examining the roots of the "Wellingtonias, I found the 

 ground in which they were growing to be full of old tree roots in 

 all stages of decay, forming a perfect nursery of fungus spawn. 

 Upon inquiry, I learned that about twelve years previously there 

 had been a row of large old elms growing upon the same ground, 

 which were all blown over or so seriously damaged during a severe 

 gale of wind as to necessitate their removal. To save troiible in 

 clearing them away, the trees had been sawn off at the base of the 

 stem, and the stumps and roots buried in the ground where they 

 had formerly grown, some of them being so slightly buried that 

 the earth placed on the top of them was scarcely 3 inches deep. 

 The stumps having been thus put out of sight, the surface of the 



