36o PLANT DISEASES 



Wissensch. Anstalten, x., 2, 74 (1893). — ^sci subclavate, 

 apex mostly rounded, 92-105 /x long, 16-25 /x thick at the 

 free part, portion between the epidermal cells 30-50 /x long, 

 base about 8 fx wide ; ascospores about 4 /x diam. 



Taphrina aurea, Fries, O/^s. Myc, pt. i. p. 217 (181 5). — 

 Asci very variable, sometimes slender and deeply sunk 

 in the leaf, 80-112 X 20-27 l^'> others are stouter, rounded 

 below, and entering but little between the epidermal cells, 

 measuring 80 x 30-40 /x ; ascospores about 4 /x diam. 



Perisporiaceae. — Perithecia distinct, not produced on a 

 stroma, coriaceous or subcarbonaceous, not provided with 

 a distinct mouth, hence splitting irregularly to allow of the 

 escape of the asci : mycelium superficial. 



Microsphaera, Lev. — Perithecia containing many asci; 

 asci ovoid or oblong, 4-8 spored ; appendages branched at 

 the tip. 



Microsphaera grossulariae, Lev., An7i. Set. Nat., 185 1, 

 vol. XV. p. 160, tab. 9, f. 25. — Mycelium cobweblike, 

 greyish-white, on both surfaces of leaves ; perithecia 

 scattered, 75-120 ji, appendages 10-20, once to twice as 

 long as diameter of perithecium, 4-6 times dichotomously 

 forked at the tips ; asci 3-5, ovoid ; spores 4-6, variable in 

 size, 15-30 /x long. 



Uncinula, Lev. — Perithecium containing several asci, 

 which are 2-8-spored ; appendages free from the mycelium, 

 curled at the undivided tips. 



Uncinula spiralis. Berk., Crypt. Bot., p. 268, f. 64. — 

 Mycelium arachnoid, amphigenous, often evanescent ; 

 perithecia minute, scattered, globose, blackish-brown, 

 appendages 10-20, variable in length, septate, occasionally 

 forked, tips loosely and spirally twisted, basal portion 



