On a JVcw Clover Disease. 



517 



in the branches, to cause their death. The microscopic exami- 

 nation of the blade shows that the protoplasm, instead of filling 

 the cell and having its natural whitish or greenish colour, is 

 detached from the cell-walls, is aggregated together, and has a 

 brownish-yellow colour, indications of the leaf being dead. 



On examining the collar or base of the stem, where it joins on 

 to the root, one finds the protoplasm in a similarly dead condition, 

 and the cells which were filled with starch completely empty. 

 Winding among the cells one can detect a largish filament filled 

 with a clear grey granular substance : this is the mycelium of 

 a fungus. Fig. 1, drawn with the camera lucida from a care- 



Fia. 2. 



FI- 1. 



Section of a leaf magnified 250 times. 

 M. Mycelium of the parasitic fungus. 

 P. liead and contracted protoplasm. 

 C. Empty cellules. 



External growth of the parasite on the 

 base of the Clover stem, enlarged 150 

 times. 



fully cut section, shows the relation of the mycelium to the tissues 

 of the plant. This mycelium abounds in the base of the stem, 

 but I have not been able to detect it either in the leaves or in 

 the root proper. 



I have, then, no doubt that this new disease is due to a fungus 

 parasitic on the interior of the clover-stem. If the diseased 

 stem be left in a dampish place for a day or a night, the whole 

 surface at the collar is abundantly covered with a white down, 

 which the microscope shows to have the same structure as the 

 mycelium in the interior of the stem. Fig, 2 shows the structure 



