3^5 



only are affected It is quite true that though many leaf fungi have 

 been found on Hevea none of these at present cause serious iniurv 

 The Pestalozzia recorded in the June number of the Tropical Acryi 

 culhinst occurred in a nursery bounded on one side by tea and the 

 only plants attached were on that side. They were then' about a 

 foot high. Practically all the diseased leaves were gathered and 

 when I visited the nursery later to obtain fresh specimens, I found 

 that the plants, then three feet high, were quite free from any 

 disease. There is no doubt that the young plants had been infested 

 by spores blown from the adjacent tea bushes. 



' Helminthosporiwn attacks rather older plants, but is again 

 apparently confined to nurseries: it has been sent in from several 

 localities. 



So far the trees are free from leaf disease, but it is not true that 

 the periodical leaf fall confers any immunity. Deciduous trees can 

 and do suffer serious injury; in fact, the injury inflicted on them is 

 greater than on other species, since they are generally deprived of 

 their foliage at a time when all their reserve food has been con- 

 sumed in the formation of new leaves which have not yet elaborated 

 a further supply. 



Mr. HOFFMAN'S comparison with an English apple orchard is 

 rather unfortunate, as the majority are hotbeds of disease, and in 

 the remainder a paying crop can only be realised by constantly 

 spraying against the attacks of fungi and insects. 



Many specimens are sent for examination which, though in a 

 sense pathological, are not mycological. Two recent cases are of 

 considerable interest, showing that the power of forming new bark 

 which Hevea possesses to such an extraordinary degree sometimes 

 produces. 



Results which are not altogether desirable. 



The first series of specimens consisted of several " knots " of 

 wood measuring from one centimetre diameter to 9x7x5 cms. 

 These w r ere cut from the trunks of trees, 10 or 12 years old, aver- 

 aging 4 to 5 feet in girth at three feet from the ground. In some 

 cases the growths cover the first five feet of the trunk. The trees 

 appear to be knobby and buttressed on the stem where affected by 

 this growth, and, on an incision being made, the bark is found to 

 be very thick and of a claret colour, and does not yield latex. 

 Covered by the thick growth of bark are the hard growths of wood 

 previously mentioned ; these are not attached to the main stem but 

 " shell out" quite easily when the outer bark has been cutaway. 

 Between the knots and the main stem is a second layer of bark and 

 often a layer of rotten latex. The trees have been tapped on the V 

 system at some unknown date, and the knots occur on the old 

 tapped surface. 



The structure of these "knots" is identical with that of the 

 " Masers knollen " of beech and other trees. They are formed in 



