THE BtTD-ROT OP PALMS IN INDIA. 259 



it from the tree. Next day a surface growth of mycelium had 

 appeared near the edges of some of the spots. On the 11th day 

 the sheaths were removed one by one from the inocuhited trees. In 

 each case the parasite had passed completely through three sheaths 

 (including that inoculated) and had entered the fourth sheath but 

 not reached its inner surface. In two of the unshaded trees insects 

 and moulds had collected on the spots and a wet rot had developed. 

 In the other three the spots were dry and permeated only by the 

 myceliimi of Pythium palmivorum. Microscopic examination 

 showed that the characters of the mycelium and its relations in 

 regard to the host cells were exactly as described above. Sporangia 

 and resting spores were borne on the surface mycelium on the 

 second and third sheaths. 



II. Two young trees were inoculated in the same manner as 

 in the last experiment. On the 10th day the free edges of the in- 

 oculated sheaths were pulled back so as to see those next below. 

 In one the next sheath was only slightly affected and no further pro- 

 gress occurred, probably because the premature disturbance of the 

 first sheath caused drying of that below. In the other, large patches 

 covered with a superficial mycelium were found on the next sheath 

 below the point inoculated. This sheath was also pulled back and 

 was found with small spots on its inner surface where penetration 

 had occurred. One small unsunken spot occurred on the surface 

 of the third sheath. In this case growth of the parasite continued 

 and five days later the sheaths were cut away one by one. Two 

 more sheaths were found penetrated by the parasite, and the next 

 sheath below was marked by a small spot on its outer surface. In 

 15 days, therefore, the parasite had passed through five sheaths and 

 infected the sixth. 



III. The material used was obtained from a recently infected 

 unopened leaf in the heart of the bud of a diseased Palmyra, which 

 was placed for 12 hours in a covered sterile watch-glass with a few 

 drops of boiled water. A good growth of mycelium extended to the 

 sides of the glass and bore quantities of sporangia. Some of this 

 was picked oE on sterile needles and sown in sterile water ; in about 



