MACROSPORIUM 



53 



or with the apex somewhat narrowed, variously muriformly 

 septate, 80-120 X 15-22 ji. 



Chlamydospores formed in the decaying substance of 

 diseased portions of the host, very irregular in form and size, 

 dark brown, either interstitial or terminal, sometimes in 

 chains. 



Pycnidia often crowded, appearing along with or after the 

 conidia ; globose, black, with a small mouth, containing 

 numerous minute, hyaline, elliptical conidia, about 3X2 fi. 



Although I have not caused conidia more than three 



Fig. 151. Macrosporiiun solani. i, tomato diseased ; 

 2, conidia in various stages of development, highly mag. 



months old to germinate, other observers have been more 

 successful, and it is quite probable that old diseased stems or 

 fruit lying about would continue to produce conidia the 

 following season. At all events, chlamydospores are present 

 in decaying parts, more especially in tomato fruit, consequently 

 the most important point is to collect and destroy all diseased 

 plants and fruit. Tomatoes should not follow a diseased crop 

 of potatoes, or the reverse. If the disease appears, Bordeaux 

 mixture would check its progress, so far as further infection 

 from conidia is concerned. 



Massee, Journ. Bd. Agric, 13, p. 232 (1906). 



Carnation macrosporium (Macrosporium tiobile, Vize.) 

 sometimes does a considerable amount of injury to cultivated 

 carnations, forming numerous small blackish spots on both 

 surfaces of the leaves and stem. The spots are irregularly 

 scattered over the entire surface of the leaves when badly 

 attacked, and the mycelium is rampant in the tissues, causing 

 the leaves to turn yellow and die. Numerous small black 



