322 Agricultural Experiment Station, Ithaca, N. Y. 



lateral cilia according to the descriptions, and de Bary only sajsthat 

 the zoospore formation takes place in the oft described way.'^ In 

 Artotrogus 2:)roliferus^'^ (deBary), the author, was unable to deter- 

 mine whetlier the zoospores were miciliate or biciliate. In the 

 vesicle they are figured as reniform, but the ultimate zoospores are 

 described as oval, one end being narrower than the other. Double 

 zoospores were also described which possess two light spots instead 

 of one. These ultimately divided, but before division, according to 

 the author, the double zoospore was like that of an organism con- 

 trolled by two opposing wills. This was net the case with the 

 biciliated zoospores observed by myself in Artotrogus intermedius, 

 until amoeboid movement was beginning after a period of swarm- 

 ing, and when fission is about to take place. Possibly de Bary 

 observed the " double" zoospores just at that time. 



In Artotrogus jpythiodes'^^ (R. et C.) the zoospores are described 

 and figured as biciliate, one cilium attached at each pointed end of 

 the zoospore exactly as I have found in the case of A. inter raeditis. 

 But in A. pythiodes the authors say that the zoospores absorb the 

 two cilia, round off and germinate, i. e., they do not divide^ if the 

 observations are clear on this point. This species was found on 

 leaves of Wolffia mitchellii. 



Other species of the genus are as follows: A, hydnosporus^^ 

 Mont, in potatoes and in dead seedling plants.^^ A. ferax (de 

 Bary) in dead insects and in dead seedlings in water. A. inegala- 

 canthxis'^^ de Bary, in dead seedlings and parasitic in prothalia of 

 Todea africana. A. lyroliferus'-^ (de Bary) saprophytic on dead 

 seedlings and insects in water; A. vexans'-^ (de Bary) in dead seed- 

 lings and in diseased potatoes;^, angnillxdae aceti'^^ {^2i.^<&hQQ}s)^ 

 parasitic in Anguillula aceti ', A. sadebeckionus (Wittmack) pro- 

 ducing epidemics of diseases in lupines and peas. Several other 

 species have been imperfectly described. 



i isZur Keuntniss der Peronosporeen, Bot. Zeit. XXXIX, 524, 1881. 



isPythiuni proliferum de Bary, Priagsh. Jahrb. f. wiss. Bot. II, 182, 1860. 



20Eoze et Coruu, sur deuz nouveaux types generiques pour les Families des 

 Saproleguees et dess Peronosporees, Aun. de sci. uat. Bot. ser. 5, II, 72, 1869. 



2iMontagne, syolloge, etc., p. 304, 1845. 



22 Bot. Zeit. XXXIX, 562, 1881. 



23Beitr. z. Morph. u. Phys. d. Pilze. IV., 19, 1881 ; Bot. Zeit. XXXIX, 578, 1881. 



2iPiing8li. Jahrb. f. wiss. Bot. II, 182, 1860. 



25 Jour. Bot. V, 119, 1876. 



26 Bot. Centralbhi, XXXIX. 318, 1887. 



