1056 AQUATIC PHYCOMYCETES 



ations or swollen complexes; sporangia borne on sympodially branched 

 long straggling uninflated sporangiophores, pyriform, 1 often much elon- 

 gated and somewhat irregular, the apex blunt and nonpapillate, 24-50 u. 

 long by 17-30 u. broad (av. 40 by 27 u.), when caducous bearing a short 

 pedicel, germinating by zoospores or less often by a germ tube, renewed 

 by internal proliferation; zoospores limoniform, biflagellate, 10-15 jx in 

 diameter when at rest, discharged in a quickly evanescent vesicle; oogo- 

 nium usually lateral, sometimes terminal, pyriform or spherical, the wall 

 becoming amber-colored and thicker with age, averaging 30 tx in diam- 

 eter; antheridium terminal or intercalary often borne on a short hypha, 

 variable in size and shape, amphigynous; oospore lying loosely in the 

 oogonium, straw-colored, averaging 25 y. in diameter, with a smooth, 

 3 [x thick wall, the contents with a large central oil globule and a small 

 oval, highly refractive, lateral body, germination not observed. 



Parasitic in stems and roots of Eycopersicum esculentum and Petunia, 

 Pethybridge and Lafferty (he. cit.), Ireland; saprophytic in water, 

 Waterhouse(1940), Great Britain. 



The excellent growth and abundant production of sporangia by this 

 parasite of phanerogams under aquatic conditions was remarked on by 

 Pethybridge and Lafferty. It strengthens our conviction that it is identi- 

 cal with Waterhouse's fungus. 



Phytophthora megasperma Drechsler 



J. Wash. Acad. Sci., 21 : 524, figs. 1-5. 1931 



(Figs. 89 A-C, p. 1055: 90 C-F, p. 1059) 



Pythiomorpha miyabeana Ito and Nagai, J. Fac. Agr. Hokkaido Imper. 

 Univ., Sapporo, 32: 50, pi. 8, figs. 1-8. 1931. 



"Mycelium intercellular in tissues of host; on artificial substratum of 

 somewhat radiating aspect, composed of freely branching hyphae from 

 3 to 8 [x in diameter; continuous in actively growing stage, later, on 

 becoming evacuated, developing numerous, rather thick septa; produc- 

 ing aerial growth in small or moderate quantity; under aquatic con- 

 ditions extramatrical growth meager. 



1 Described as "inversely pear-shaped." According to the usage employed through- 

 out this book, the term should be "pyriform," i. e., as the fruit hangs naturally on the 

 tree. 



