208 THE LOWER FUNGI— PHYCOMYCETES 



essentially with Phytophthora. The sporangiophore branches as 

 in that genus, and sporangia arise successively. The pedicel 

 cell is regarded by Sawada (in Tanaka, 1920) as being merely a 

 thickening of the wall at the basal end of the sporangium. 

 Earlier Wilson (1914 b) had treated Kawakamia as a well defined 

 genus showing relationship with Basidiophora. The writer feels 

 that there is no basis for separating it from Phytophthora. 



The genus Blepharospora Petri (1918; 1924) was founded on 

 B. camhivorai Petri, cause of the inky spot disease of chestnuts 

 in Italy. The species is said by Petri to possess a long, 

 unbranched sporangiophore terminated in a single sporangium. 

 Further, the sporangiophores are said to develop only in a liquid 

 medium. Peyronel (1920) tr^nsierreA Phy. terrestria ^hevhoko^ 

 to the genus as B. terrestris (Sherb.) Peyronel. Other species of 

 Phytophthora are closely related to it. Buisman (1927) advocates 

 the merging of Blepharospora with Phytophthora, pointing out that 

 there is in fact no tangible basis of separation. She uses the 

 binomial, Phy. camhivora (Petri) Buisman. 



The genus Pythiomorpha Petersen (1910) founded on the single 

 species Pythiomorpha gonapodioides Petersen (Fig. 73), is made the 

 sole representative of a new family, Pythiomorphaceae, by Peter- 

 sen. It is discussed at length by von Minden (1916), Buisman 

 (1927), and Kanouse (1925). The vegetative mycelium occurs 

 in plant substrata, twigs, fruits, etc., immersed in the water, and 

 forms a prominent floating white mat. The hyphae are of small 

 diameter and are provided with numerous small protuberances 

 which give them a characteristically irregular appearance. 

 Highly refractive granules, believed by Petersen to be cellulin, 

 are present in the cytoplasm. The presence of these granules 

 and the somewhat constricted aspect of the hyphae have led 

 some workers to regard the species as intermediate between the 

 Pythiaceae and Leptomitaceae. The extramatrical hyphae 

 bearing the sporangia are cylindrical, straight, and unbranched. 

 The sporangia are terminal, ovate, broader below and somewhat 

 narrowed above, and have a definite papilla of dehiscence. They 

 proliferate repeatedly, the sporangia which foUow the primary 

 being developed either within it or, by further growth of the 

 hypha, at a considerable distance beyond its mouth. According 

 to von Minden the swarmspores are delimited in a thin-walled 

 vesicle at the apex of the sporangium. The formation of the 

 vesicle is denied by Kanouse. The swarmspores are reniform 



