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the rubber tree or not. This indeed is a matter of little importance 

 to the planter. If the fungus can get into the terminal bud of a rub- 

 ber tree of considerable size, and kill it to the ground in a few days, 

 it is sufficiently serious to make it requisite that steps should be taken 

 against it by every planter. 



The following experiments with spores of the Diplodia sent from 

 Borneo, though not yet completed, are of some interest. I attempted 

 to infect seven plants of Hevea hraziliensis with the spores in different 

 ways. 



A. A young plant of some age which had sprung up from a 

 seed placed at the foot of a tree and had been once or twice cut down; 

 from the stump a shoot six feet tall was growing. I made a small 

 tear about % inch long about half way up the stem and puta 

 number of spores on the wound. The wound had exuded a little 

 latex in which I put the spores. June I, 12 p.m. 



On the next day, at the same hour, I removed some of the spores 

 and examined them, several had commenced to germinate emitting 

 a short mycelial process from just below one end of the spore. Other 

 spores showed at the same spot a small conical process which had 

 not by then had time to rupture and let out the mycelial thread. 



This experiment showed the rapidity with which these spores 

 germinate on reaching a suitable spot for growth. The wound dried, 

 and looked brown for some days, but though it has not healed at pre- 

 sent it has not enlarged. 



B. Seedling about a foot tall, in a pot. The bud was pinched 



off and spores placed on the wound. 



C. It is a similar plant, the bud not removed but rubbed with 



spores. 



D. A similar plant, slightly bigger. A small piece of cortex 



removed, about half way up and spores put on the wound 



E. A similar plant with young leaves just expanding still soft 



and pendulous. These were rubbed with spores. 



F. A seedling about a foot tall, bud pinched off and spores put 



on the wound. 



G. A similar plant, the bud was not cut off but spores were 



placed, on it. May 28th. 



I may say at once in the cases of C, G. and A, in all of which 

 spores were put on the uninjured bud, no results at all followed, and 

 it seems clear the bud cannot be infected except through a wound. 



B. On June 2nd. The uppermost leaf is dead and a small 

 portion of the stem a quarter of an inch long is black 

 and mouldy, by June 6 no further progress of the disease 

 was visible. On examining the dead portion, I found the 

 petiole covered with a mycelium of very fine threads. 



