44 CEANBERRY DISEASES. 



on decaying fruit it occasionally produces the coreminm form. The 

 fungus probably does not cause decay of the fruit, except where the 

 skin has been injured to permit its entrance. 



Leptothyrhim pomi (Mont.) Sacc. ? — Occasionally about picking 

 time there appear on cranberries minute black fungous specks or 

 spots having an appearance identical with that of the " flyspeck " 

 or fruit speck of the apple. Microscopical examination shows that 

 these spots consist of thin, dense, superficial, dark-colored, short- 

 celled, rather thick-walled hypha?. When old the spots are slightly 

 convex, and when examined in cross section show a somewhat lighter 

 colored compact cellular mass closely attached to the epidermis of the 

 fruit (PI. V, fig. 15). Specimens kept for a long time in a moist 

 chamber have never shown any indication of spore formation. A 

 study of these specks in diiferent stages of formation shows that they 

 arise from a germinating spore. An anastomosing, dark-colored, 

 thick-walled mycelium is formed (PI. V, figs. 13 and 14), which 

 continues for some time to increase in size and thickness until it 

 reaches the condition shown in Plate V, figure 15. A careful ex- 

 amination of the surface of berries bearing these specks revealed 

 the presence of three different kinds of fungous spores (PI. V, fig. 16, 

 «, 5, and c) . Those shown at h and c were rather frequent. The form 

 shown at a is the only one which was found germinating, and as 

 remains of similar spores were found connected with the very young 

 specks we are led to think that they are produced b}^ these spores. 

 We have no means of knowing to what genus of fungi any of these 

 spores belong. Those shown at c bear a strong resemblance to 

 Cladosporium. 



So far as we have been able to learn, no one in this country has 

 found any spores produced by this fungus. We have attempted to 

 grow the plant in culture media, but without success. LahreUa pomi 

 Montague '''' was described as follows : " Macula nulla, peritheciis 

 ellipticis minimis rugosis nitidis, sporidiis globosis." In view of 

 the mention of globose spores in the description and our scanty knowl- 

 edge of the original plant, it is rather doubtful whether the plant 

 we are dealing with is that described by Montague. 



This fungus has only been seen from one locality, Parkdale, N. J. 

 It does not seem to injure the fruit except that it renders it unsightly. 

 Thorough spraying will j^robably jDrevent its apjjearance. 



riTNGI OCCURRING ON THE LEAVf^S OR STEMS. 



Several of the species of fungi already described as attacking the 

 fruit are also found on leaves or stems. The following species have 

 been found only on the leaves or stems of the cranberry. So far as our 

 present knowledge of these goes, they do not cause sufficient injury 



110 



