134 British Fungi, 



Quart. Journ. Microscop. Sci. vol. 23 (1883), p. 487, 

 pi. 24, fF. 1—10. 



Pythium equisefi, Sadeb. in Sitz. d. Bot. Ver. der 

 Prov. Brandenb. 1874, p. 166. 



Pythium vexans, De Bary, Bot. Zgt. 1881, p. 537, 

 t. V. ff. 3—7. 



Parasitic or sapropbj-^tic in various plants, frequent 

 in cress seedlings grown in damp, shady places. 

 Common. 



Pythium proliferum, De Bary. 



Mycelium often profu-ely branched ; zoosporangia 

 elliptical or lemon-shaped, beaked, wall thick, zoo- 

 gonidia reniforra, biciliate, escaping through the 

 diffluent apex of the beak, a second zoosporangium 

 usually originates from the base and wdthin the first 

 empty one ; oospores spherical, epispore smooth, 28- 

 35 /u. diameter; antheridia short, clavate, curved. 



Pythium proliferum, De Bary, Pringsh. Jahrb. ii. 

 p. 182, t. xxi. figs. 28—37; Sacc. Syll. vii. n. 926; 

 V\rard, Quart. Journ. Micros. Sci. vol. 23 (1883), 

 p. 497, pi. 24 and 25, figs. 11—21. 



On putrid insects and plants in stagnant water. 

 Uncommon. 



Not a good Pythium, departing from typical forms 

 in the thicker wall of the zoosporangia, and in the 

 proliferous habit, or development of one zoosporangium 

 within another, as in Saprolegnia. 



Pythium cystosiphon, Lindstedt. 

 Mycelium entophytic, aseptate or with an occasional 

 septum, slender, 4-5 fi thick, penetrating the cells 

 of the host ; zoosporangia on short branches, formed 



