256 COLOOASIA BLIGHT. 



stomata, never branching from the base of the conidium and 

 terminating with a short slender pedicel-cell ; the conidia lemon- 

 shaped with a prominent obtuse beak and falling with the 

 thickened septum between the conidium and the pedicel-cell 

 which forms a peculiar short tail to the spore. The other charac- 

 ters are as in Phytophthora, from which genus, according to Miyabe's 

 description, it differs only in the pedicel-cell, a tail-like appendage 

 to its conidium, and in the shape of the conidia and conidiophores. 

 These differences appear to be of very slight systematic value and 

 whatever may be said for Miyabe's type, Kawakamia Cyperi, the 

 fungus now under consideration can scarcely be removed from 

 Phytophthora. In mycelial characters, haustoria, sporangiophores 

 and sporangia there are no points which cannot be paralleled 

 amongst other Phytophthoras, excepting that the pedicel-cell may be 

 of unusual length. It is, however, often very short in culture and 

 such short stalks, remaining attached to the sporangium, are some- 

 times found in Ph. infestans 1 and Ph. Phaseoli 2 . The characters of 

 the sexual reproduction, unknown to Sawada, are equally in close 

 similarity to other Phytophthoras, such as Ph. parasitica. Hence 

 it is not possible to maintain Sawada's nomenclature and the species 

 should be restored to the position given it by Raciborski. 



Amongst other Phytophthoras, only a few show characters 

 similar to those of Ph. Colocasice. Of these the chief is Ph. Phaseoli 

 Thaxt., a species parasitic on Phaseolus lunatus in the United States 

 and Russia. From an examination of Clinton's 3 figures it can 

 hardly be doubted that the peculiar type of development of the 

 sexual organs described above in Ph. Colocasice, and also by Dastur 4 

 in Ph. parasitica, is also found in Ph. Phaseoli. Clinton, indeed, 

 states that for a long time it was difficult to decide whether or not 

 the oogonial thread did not actually penetrate the antheridium 



1 De Bary, A. Die gegenwartig herrschende Kartoffelkrankheit, Leipzig, 1861, figs. 4, f> 

 and 9. 



2 Clinton, G. P. Downy Mildew of Lima Beans. Conn. Exper. Sta. Report, 1905, p. 288. 



3 Clinton, G. P. Artificial cultures of Phytophthora. Conn. Exper. Sta. Report, 1907-08. 

 Plates LXXIV and LXXV. 



* Dastur, J. F. On Phytophthora parasitica nov. spec., a new disease of the Castor oil 

 plant. Mem. Dept. of Agrie. in India, Bot. Ser., V, No. 4, 1913. 



