148 EXPERIMENT STATION RECORD. [Vol.38 



"The geographical distribution of the pest is suggested by its presence in 

 Florida, Georgia, North Carolina, New Yorli, and Michigan. The occurrence 

 of this disease under such different climatic conditions and in such a diversity 

 of hosts malies it certain that the nenia causing it is another species which, 

 lilte some other destructive members of its genus, can adapt itself to widely 

 varying conditions. As yet too little is known about this parasite to accurately 

 estimate the damage done by it. 



"The occurrence of the parasite in the tubers of the potato is a peculiarly 

 significant fact and again points to the necessity of being particularly careful 

 to plant only perfectly healthy potatoes. The mercuric-chlorid treatment of 

 potatoes, as for scab, decreases the vitality of the nemas." 



Cereal smuts, V. Zeman (Rev. Facult. Agron. y Vet. La Plata, 2. ser., 12 

 {1911), No. S, pp. SSOSJfO). — This is a discussion of UstUago tritici, Tilletia 

 tritici, and T. levis on wheat ; U. nuda and U. hordei on barley ; U. avence and 

 v. Imvis on oats; and TJ. maydis on maize, as regards the forms and effects of 

 attacli and control measures available in Argentina. 



Overwintering and distribution of cereal rusts in a subtropical climate, 

 G. Gassnek (Ztschr. Pflanzenkranlc, 26 (1916), No. 6-7, pp. 329-574).— In Pur- 

 suance of an account previously noted (E. S. R., 36, p. 542), the author dis- 

 cusses overwintering of cereal rusts and the significance of host alternation 

 In the eastern subtropical parts of South America, overwintering by the uredo 

 form in the warmer regions, spore distribution by air movements, and rust 

 dissemination by means of seed. 



In spite of the fact that teleutospores were regularly produced, it could not 

 be shown that this method or that of host alternation was employed as a means 

 of overwintering by Pucdnia graminis, P. maydis, P. triticina, or P. coronifera. 

 The seed were not shown to carry over the infection regularly, nor was there 

 any evidence of the presence of a mycoplasm. It is thought that P. gra/minis 

 and P. maydis overwintering elsewhere may be brought by air currents, the 

 uredo form of the former fungus being known to winter in southern, the second 

 in tropical, Brazil. Evidence regarding the agency of air currents is discussed. 



Frost injury to cereals, H. Zimmermann (Ztschr. Pflanzenkrank., 26 (1916), 

 No. 6-7, pp. 321-323, pi. 1). — The effect is described (principally on rye, also 

 on wheat and rye grass) of freezing alternating with warmer weather during 

 parts of March, 1915, in Mecklenburg-Schwerin and Mecklenburg-Strelitz. The 

 plantlets were loosened, the root system was largely suppressed, the plants were 

 stunted and weakened, and attacks by nematodes and insects were apparently 

 increased. 



A girdling of bean stems caused by Bacterium, phaseoli, J. H. Muncie 

 (Science, n. ser., 46 (1917), No. 1178, pp. 88, 89).— The author reports having 

 found in July, 1914, a peculiar girdling of the stems and branches of field 

 beans in several localities in Michigan. Since that time the disease has been 

 collected in various parts of the State. 



The disease appears at the nodes of stems and branches as small, water- 

 soaked spots. These enlarge, encircling the affected parts. Later these dis- 

 eased areas become amber colored and the girdling is usually completed by the 

 time the pods are half mature. The diseased tissue is said to be so weakened 

 that the stem breaks at the affected node. The signs of the disease may ap- 

 pear on the stems before there is any evidence of the bacterial blight on the 

 pods. Inoculations into stem nodes of healthy plants with pure cultures of 

 B. pliaseoli have produced typical signs of the disease. 



It is believed that infettion results from the washing of bacteria from af- 

 fected cotyledons or leaves to the axils of the leaves, but the method of entry 

 of the organism has not yet been determined. 



