254 



COLOCASIA BLIGHT. 



Name of plant. 



Opuntia Dillenii. 



A young plant. 



Lepidium sativum. 

 Seedlings in a pot. 



(Enothera bienn is . 

 Seedlings in a pot. 



Ditto 



Glarkia e I eg an s , 

 Seedlings in a pot. 



Salpiglossus varia- 

 bilis. Seedlings 

 in a pot. 



Schizanthus return 

 and mixed spp. 

 Seedlings in a pot. 



Fagopyrum esculen- 



turn. Seedlings 



in two pots. 

 Gilia nivalis and 



mixed spp. Seed 



lings in a pot. 



Previously known 

 to serve as 

 host for : — 



Ditto 



Ph. cuctomm, omni- 

 vora var. Arecce, 

 Faberi and Syrin- 

 ges known on 

 several cacti. 



Ph. omnivora. 



Ph. omnivora, omni- 

 vora var. Arecce, 

 Faberi, parasit- 



Ph. omnivora, omni- 

 vora var. Arecce, 

 Faberi, parasit- 

 ica. 



Ph. omnivora, omni- 

 vora var. Arecce, 

 Faberi, parasitica 

 known on Salpi- 

 glossus spp. 



Ph. infeslans, omni- 

 vora, omnivora var. 

 Arecce, Faberi, 

 parasitica known 

 on Schizanthus 

 spp. 



Ph. omnivora, para- 

 sitica known on 

 Fagopyrum spp. 



Ph. omnivora, parasi- 

 tica known on 

 Gilia spp. 



Nature of 

 inoculation. 



Steins and buds in- 

 oculated without 

 wounding. 



The seedlings sprinkl- 

 ed with the suspen- 

 sion of zoospores. 



As in Lepidium sati- 

 vum. 



Ditto 



Ditto 



Ditto 

 Ditto 



Ditto 

 Ditto 



Ditto 



Results. 



Negative. 



Do. 

 Do. 



Do. 

 Do. 



Do. 

 Do. 



Do. 



Several seedlings droop- 

 ing after three days. 

 Placed in water on a 

 slide gave a copious 

 growth of Phytoph- 

 thora Colocasice, 



bearing sporangia in 

 24 hours. Both the 

 cotyledons and the 

 hypocotyl were in- 

 fected, the latter 

 being as a rule more 

 severely attacked. 



Several seedlings 



showed drooping 



cotyledons after two 

 days. On the third 

 day a number had 

 collapsed. About 60 

 or 70% of these in- 

 oculated died. Hy- 

 phse with sporangia 

 of Phylophthora Col- 

 ocasice developed 

 in from 6 to 24 

 hours, when placed in 

 water. 



