1182 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



" The base of the stem just above the ground-line becomes covered with 

 a white fluffy substance, the mycelium of the fungus. This mould 

 gradually grows up the outside of the stem if the atmosphere remains moist 

 and the temperature sufficiently high. After some time the fluffy mould 

 collapses and becomes more compact, and bears numerous variously 

 shaped black bodies, which sometimes attain the size of a grain of wheat, 

 imbedded in its substance. These bodies, which consist of densely 

 compacted fungus spawn, are called sclerotia. During this period of 

 development of the fungus the Potato stem becomes limp, and the leaves 

 wilted, and both perish early in the season." 



" When the weather is dry and warm, the mycelium extends most 

 vigorously in the hollow of the stem, whose numerous sclerotia are 

 formed, very little fluffy mycelium appearing on the surface of the stem." 



" Collecting and burning diseased plants is the only certain method of 

 stamping out the disease. If infected tops are left on the ground to 

 decay, the sclerotia remain in the ground until the following season, when 

 they form reproductive bodies that bear spores which infect the growing 

 crop. In addition to the Potato, Beans, Peas, Cucumbers, Marrows, 

 Turnips &c, are also attacked ; in fact, probably every kind of cultivated 

 plant and also many weeds are susceptible to the attacks of fungus." 



B.N. 



Potato Failures : a preliminary Report. By F. M. Rolfs (U.S.A. 

 Dep. Agr., Exp. Stn. Colorado, No. 70, March 1902, with 12 plates).— This 

 report is of special interest in drawing the attention of Potato-growers to 

 a destructive disease of the Potato, which is attributed to Bhizoctonia 

 Solani, Kuhn. The first account of its occurrence in America was 

 recorded ki 1901. 



During the summer of 1900 it was brought to the notice of the writer 

 in Long Island, where Potato-growers complained of the early wilting or 

 drying of the vines caused by a stem rot resembling the stem rot of 

 Carnations. Examination of plants recently killed revealed the presence 

 of this fungus on stems and roots. In thirty plantations on this island 

 the Bhizoctonia was constantly present in the pith and on the outside of 

 the stems and roots, and by experiment it has been proved that it is an 

 active parasite on the Potato plant. 



In many sections it is reported that large vines gave promise of 

 an abundant yield, but when digging time comes it is found that so 

 few tubers have set that it does not pay to dig them. Many vines do 

 not produce a single tuber. It is by no means an uncommon occurrence 

 for the vines to set an abnormal number of small Potatos, or " Little 

 Potatos " as they are called. These often occur in compact clusters, and 

 are so small as to be worthless. Another condition is the dying of Potato 

 plants. All of which conditions may be produced by attacks of Bhizo- 

 ctonia. 



The hyphffl of the fungus are often found on the surface and in the 

 scab ulcers of Potatos. These hyphfle give rise to irregularly shaped dark 

 masses known as sclerotia, which vary in size from that of a mere speck 

 to half an inch or more in diameter. These sclerotia resemble small bits 

 of earth, but by placing the Potatos in water, these bodies become black 



