Minnesota Plant Diseases. 



431 



Urocystis, 



cepulas, 320 



occulta, 303 



violje, 393 



Uromyces, appendiculatus, 319 



caladii, 392 



caryophyllinus, 373 



trifolii, 292 



Ustilagineae (see smuts). 



Ustilago, avenK (Fig. 146), 293, 294 

 bromivora, 303 



crameri, 303 



hordei, 300, 302 



maydis (Figs. 148, 149), 297, 298 

 neglecta, 394 



nuda, 300 



tritici (Fig. 72) 157, 297 



violacea, 371, 393 



Variation and predisposition, 96 



relation to disease, gi 



Varieties, rust-proof, 97 



selection of and prevention 

 of disease, 96, 206 



Vegetable worms, 16 



Velvet-stemmed Collybia rot 



(Fig. 130), 264,265 



Venturia pomi (Figs. 183, 184, 

 i8s), 3SI, 352, 353 



Verbena, powdery mildew of 396 



Vertebrates, degeneration, 10 



Vetch )Owdery mildew of, 395, 396 

 spring, bacteria of nudules 

 (Fig. 99), 196 



Vicia sativa, bacteria of nodules 



(Fig. 99), ig6 



Vinegar bacteria, 191, 195 



Vines, anthracnose of, 307, 368 



black rot of, 365, 366 



downy mildew of (Figs. 196, 

 197, 198), 112, no, 



368, 369, 370 

 powdery mildew of, 366, 367 



Vineyards, disease of, 347, 36^ 



Violet, cluster cup rust of, 386 



downy mildew of, 112, 3Z4 



rust, 373 



smuts of, 158, 371, iPJ 



spot of leaf, 381, 382 



sterile-fungus rot of, 329 



Wall flower, white rust on, 330 



Water cress, white rust on, 330 



Water, 



flea, parasites of, 67 



hot, method for smuts, 225, 226 

 molds (Fig. 42), 105, 106 



molds, distribution of 



spores, 27 



molds, on animals, 66 



molds, on crabs, 67 



molds, on fish, 71 



molds, saprophytic habits, 36 



Watermelons, downy mildew of 334 



Weeping fungi (Fig. 78), 



153, 154, 169, 245 

 basidium of (Fig. 78), 166 



Wet rot of potato (Fig. 172), 340 

 Wheat, brand, 297 



crop rotation and bacteria, 196 

 ergot of, 130, 307 



formalin treatment of stink- 

 ing smut, 221, 223, 

 loose smut of (Figs. 71, 



72), 15s, 157, 297 



loose smut of, formalin 

 treatment, 223 



Wheat rust (see also rusts of 

 wheat), 10 



(Figs. 73, 74), 159, 163 to 166 

 and variation, 97 



distribution of spores, 27 



epidemics and pure cul- 

 tures, 100, 206 

 host succession, 26 

 infection of grass leaf (Fig. 



29), 61 



kinds of spores (Fig. 11), 25 

 scab, 310 



stinking smut of (Figs. 71, 

 147), 15s. •JPi, 29(> 



White cohosh, rust of, 386 



piped oak, 240 



rusts, formation of leaf green 



in petals of hosts flower, 85 

 rusts of -mustards, cabbage, 

 etc., 330 



Wild flowers, cluster cup rusts 



of, 386 



Wild mushrooms (Fig. 89), 180 



Wild rice, ergot on, 130 



Willow blight (Fig. 134), 272, 273 



leaf rust (Fig. 138), 279 



