THE FUNGI WHICH CAUSE PLANT DISEASE 367 



excrescences 3-25 mm. in diameter, mievenly disposed, often 

 separated by the scars of the sori of previous seasons, tongue or 

 wedge-shaped, 1.5-3 mm. broad by 2-5 mm. long at the base and 

 6-12 mm. high, chestnut-brown; teliospores 2-celled, ellipsoid, 

 16-21 X 37-48 n, somewhat narrowed above and below, slightly 

 constricted at the septum, wall pale cinnamon-brown, 1-2 n 

 thick; pores 2 in each cell, near the septum. 



I. .iEcia on apple, pear, Crataegus, quince, moimtain ash, 



III. Telia on Juniperus virginiana and J. barbadensis. Common 

 and widely distributed in eastern America. 



The teUal galls are from 0.5 to 2.5 cm. in diameter, very ir- 

 regular. In late spring dark-brown spore-masses, later yellow- 

 orange, 0.5 to 2.5 cm. long appear. 



The Rcestelia spots are 0.5-1.0 cm. across. Pycnia blackish 

 above. The aecia are on thickened hypophyllous spots, long, 

 slender, soon splitting and becoming fimbriate. Mesospores occur 

 occasionally. The seciospores germinate on the cedar. The 

 mycelium stimulates the hosts to extra formation of parenchy- 

 mateous tissue. 



G. juniperinum (L.) Mart. 



I. iEcia (=Roestelia penicillata [Pers.] Fries.) hypophyllous, 

 in annular or crowded groups, 2-5 mm. across on large thickened 

 discolored spots, at first cylindric, 0.5-1.5 rani, high, 0.5-1 mm. in 

 diameter; peridium soon becoming finely fimbriate to base and 

 somewhat twisted or incurved; peridial cells usually seen only in 

 side view, rhomboid, very thick, 30-35 x 60-90 fi, outer wall 

 medium thin, 2-3 n, smooth, inner wall medium thick, 7-10 n, 

 rugose, side walls very coarsely rugose with thick, somewhat 

 irregular ridges, roundish or elongate ridge-like papillae inter- 

 spersed; aeciospores globoid, very large, 28-35- x 30-45 n, wall 

 chestnut-brown, thick, 3-5 n, rather finely verrucose. 



III. Telia caulicolous, appearing on hemispheric swellings 

 (1-4 cm. long) breaking forth along the sides of the larger branches, 

 or on subglobose galls (1.5-2 cm. in diameter) on the smaller 

 branches, applanate, indefinite, usually of considerable size, often 

 covering the whole hypertrophied area, sometimes becoming 

 patelliform when expanded, chocolate-brown; teliospores 2-celled, 

 ellipsoid, 18-28 x 42-61 n, usually slightly narrowed both above 



