684 AQUATIC PHYCOMYCETES 



Walls bearing ridged markings B. tenuis, p. 692 



Sporangia broadly ellipsoidal or dome-shaped and truncate 



Sporangia broadly ellipsoidal in dense clusters, basal cell wide, 



tapering distally, branching apically B. glomerata, p. 692 



Sporangia dome-shaped and truncate, few, basal cell cylindrical, 



only slightly expanded distally B. tnmcata, p. 693 



Blastocladia pringsheimii Reinsch 



Jahrb. wiss. Bot., 11:298. 1878 

 (Fig. 46 D, p. 680) 



Basal cell variable in habit and size, generally cylindrical, 400-1000 a 

 long by 30-90 \x in diameter, wall smooth or rough, up to 8 u. thick, 

 expanded distally and simple or giving rise to cylindrical, apically ex- 

 panded, subdichotomously, subumbellately, or irregularly arranged 

 branches or broad lobes up to 240-400 [x long by 80-160 jx in diameter, 

 setae present or absent, 2-6 \x in diameter, generally bulbous at the base, 

 holdfasts richly branched, the whole thallus up to 2000 \x long, contents 

 with many globules; sporangia borne along the tips of the branches or 

 over the surface of the swollen lobes, predominantly cylindrical or 

 narrowly clavate, often somewhat curved, also narrowly ellipsoidal, 

 fusiform, long ovoid, or siliquiform, 70-350 [x long by 13-70 [i in diam- 

 eter, usually at least from three to five or more times as long as broad, 

 the discharge papilla often bearing an endogenous plug, zoospores ovoid 

 and 6-9 (x long by 5-6 jx in diameter, or spherical and 12-15 \x in 

 diameter, emerging individually or in a columnar or pyriform group 

 surrounded by an evanescent vesicle bearing an apical, persistent plug 

 (the remains of the discharge papilla), empty sporangia often deciduous ; 

 resting spores usually borne among the sporangia, ellipsoidal, ovoidal, 

 or spherical with truncate base, 40-99 \x long by 30-50 [i in diameter, 

 wall thick, brownish, punctate, upon germination the wall splitting and 

 the contents becoming divided into planonts. 



Forming dense pustules on apples, Reinsch (he. cit.), fruits and twigs, 

 Minden(1902: 823; 1915:603, fig. 13 [p. 580]; 1916: 189, 21 1, text figs. 

 15-17, pi. 4, figs. 25 33), substratum (?), Laibach (1927), Behrens (1931), 

 Germany; apples and other plant materials, Thaxter (1896a: 51, pi. 3, 

 figs. 1-13), fruits of apple, crab apple, rose, Crataegus, Kanouse (1927: 

 297, pi. 33, figs. 8-13), apples, Cotner (1930a: figs. 1-4), apples, twigs, 



