DISEASES OF PLANTS. 668 



tinned his investigations and affirms his previous conehision that the fungus l)elongs 

 to tlie order Chytridinea). The i)arasite attacks the voung roots, shutting off their 

 nutrition and accouiphshing their destruction. Tlie roots of diseased trees contain 

 but few root hairs, and young roots are very rare, and as a result the nutrition of the 

 tree is imjiaired. If an examination be made of the roots the cortex will be found 

 invaded by a nonseptate mycelitun, which not only invades the tissues, but often 

 completely tills the cells. The fungus does not extend into the woody tissue of the 

 root. The effect on the tree is generally noticed by the destruction of the higher 

 l)ranches, since the roots are unable to furnish the normal amount of nutrition and 

 the lower roots appropriate Avhat is supplied, leaving the tops of the trees to perish. 

 Some of the morphological phenomena of the fungus are described in considerable 

 detail. 



Woodiness of the passion fruit, N. A. Cobb {Agr. Gaz. New South Tra7es, 12 

 {1901), No. 4, pp. 407-418, pi. 1, fiiji^. IS). — Attention is called to a diseased condition 

 of the passion vine, the fruit of which is used to a considerable extent in Australia. 

 The disease, which the author designates as "woodiness," has been known for 10 

 years or more and is of widespread distribution. The name of the disease is derived 

 from the characteristic appearance of the fruit. The affected vines are unhealthy in 

 general appearance, their color being more or less yellowish green. The leaves are 

 smaller, distorted, and spotted, and the branches more or less twisted and crooked. 

 The rind of the fruit develops abnormally, the fruit frequently falling before maturity, 

 and that which remains on the vines is worthless on account of the absence of edible 

 pulp and the woodiness of the rind. The seeds of diseased fruits are invariably 

 smaller and lighter in weight than sound ones. Just before the time for ripening, 

 the diseased fruits assume an unnatural green color and not Infrequently crack. 



Various causes have been suggested as producing this disease, among which are 

 exposed position, frosts, poor soils, improper fertilizers, and insufficient moisture. 

 Associated with this disease the author has observed a fungus which is as yet not 

 definitely determined. He believes from his investigationd that the fungus is the 

 specific cause of the disease, although as yet there is no direct evidence to substantiate 

 this claim. Various remedies are suggested for the prevention of the disease, the 

 principal of which are fertilizer mixtures by the use of which more vigorous vines 

 are secured. It is claimed that the disease can be communicated through the planting 

 of seeds from infected fruit, and the author recommends propagation by cuttings and 

 layering wherever practicable. It is believed — although no experiments have been 

 conducted to ascertain the fact — that the growth of the fungus may be prevented by 

 spraying the vines with Bordeaux mixture. 



Violet rusts of North America, J. C. Arthur and E. W. D. Holway [Minne- 

 sota Bot. StiidU'K, 2. aer., 1001, pt. 5, pp. 631-641, pi- 1) . — The occurrence, distribution, 

 and host plants are described of jEcidium pedatatum, Puccinia violx, and P. effusa. 

 The authors point out the distinctive characteristics of these different species, describ- 

 ing their different phases in detail. Four additional species of violet rusts are known 

 to occur in Europe, and it is thought that they may eventually be found in this 

 country. 



Chrysanthemum rust, Ciiifflot {Gard. Chron., 3. ser., 39 {1901), No. 753, pp. 

 351, 352). — In a translated article the author gives directions for the prevention of 

 chrysanthemum rust. Tliis consists of a winter treatment in which the leaves of 

 affected plants sliould )je collected and burned, and the pots and old stems sprayed 

 with a solution of pota.ssium sulpbid. In'the spring growers should choose buds not 

 infected with the disease, and l^efore using them they should jje carefully examined 

 to see that no pustules of rust are present. Before putting them in the frame it is 

 recommended that they should be plunged in a solution of potassium sulphid. The 

 summer treatment consists of the removal and burning of affected leaves and the 

 spraying of plants with potassium sulphid solution. 



