MYCOLOGICAL SECTION. 113 



striae of the bark, the central portion becomes more evidently de- 

 stroyed, and in severe cases the woody tissues beneath appear as if 

 burned or corroded, so deeply sometimes as to reach the pith. 



On the leaves. — The action of the fungus on the leaves is similar 

 to that upon the stems, and it is certainly very evident that where 

 the diseased spots are numerous and the development of the fungus 

 proceeds without interruption both shoots and leaves must succumb 

 to the parasite. The intensity of the disease upon the shoots may 

 cause the destruction of the young leaves even when the latter are 

 not directly attacked. 



0?i the berries. — So far as my own observations are concerned, the 

 severity of this disease has been especially marked upon the fruit. 

 In order to appreciate the full extent of the injury occasioned to the 

 berry one has only to consult Plate IV, Fig. 1, which represents a 

 bunch of Elvira received from Mr. Wanner, of South Carolina, af- 

 fected with Anthracnose. The progressive stages of the malady are 

 fully illustrated; a little to the left of the center is a berry showing 

 the first external manifestations of the disease. There is a small spot, 

 grayish in the center, where the cuticle of the berry has been de- 

 stroyed, with a dark-brown border. Previous to the bursting or 

 rupturing of the cuticle the entire spot is of a deep brovrn color. 



These sj)ots enlarge, retaining a more or less regular, rounded out- 

 line, and between the light-colored central portion and the dark 

 border-line there often appears a well-defined band of bright vermil- 

 ion. Finally, under the action of the disease the berries begin to 

 wither and dry uj), leaving nothing apparently but the skin and the 

 seeds. There is no browning of the tissues of the berry, as in the 

 case of the Black-Rot, nor does the skin shrivel, as in that disease, 

 leaving prominent and very irregular ridges, but the circular spots 

 first formed are easily seen and the colorings characteristic of the 

 disease are retained, imparting a striking appearance which has given 

 rise to the local name of "Bird's eye rot." A berry may be attacked 

 upon one side when it is not more than half grown ; it then becomes 

 irregular in shape, the diseased part making no further development, 

 and it sometimes happens that this side cracks open, exposing the 

 seeds, which are gradually forced out by the unequal growth. 



THE FUNGUS. 



The fungus of Anthracnose (Sphaceloma ampelinurii) doubtless 

 belongs to the same class as that which includes the fungus of the 

 Black-Rot, but the several stages of its development have never been 

 satisfactorily made out. We only know it in its active or disease- 

 producing form, the various details of which are illustrated in Plate 

 IV. The spores of the Sphaceloma germinate readily in water, and 

 if these germinating spores are sown upon the green and healthy parts 

 of the vine the characteristic spots of Anthracnose s^ill appear in 

 about eight days. In often-repeated experiments the disease has 

 shown itself at the points where the spores were sown, and nowhere 

 else. 



REMEDIES. 



The Sphaceloma grows very near the surface, and as soon as it has 

 burst through the epidermis it is practically exposed in all its parts 

 to the direct action of fungicides. Much mischief to the vine may 

 8 AG— '86 



