152 EXPEEIMENT STATION RECORD, 



meut and exhaustion of the plant. This becomes yellowed, and easily wilts and 

 dies in case of unusual heat or dryness. The losses observed in crop returns are 

 said to be due to the impoverishment of the plant, (1) by stoppage of channels 

 and (2) by withdrawal of material (a) for the building of the giant cells and 

 of the lateral roots and (b) for tbe nourishment of the parasites. The parasites 

 are thought to produce on entering the root a stimulation which occasions the 

 observed abnormal cell development. The giant cells are thought to function 

 somewhat as glands or nectaries, producing material suitable for nourishment of 

 the nematodes. • 



Averting nematode injury, KEiJGEE (Bl. Zuckerriibenbau, 18 (1911), Nos. 

 11, lip. 29-'i-300; 18, pp. 311-313; abs. in Ztschr. Landw. VersucJisw. Osterr.. 14 

 (1911), No. 12, p. 1479). — This is a preliminary report on the author's study of 

 nematodes on sugar beets continued for 4 years and not yet completed, but 

 from which the following conclusion may, in his opinion, be justly drawn : 



Nematode attack is favored by poverty of soil, by injurious constituents 

 therein, and by attacks of other parasites. Two plans for the protection of the 

 crop are indicated. The first, which aims to limit increase and perpetuation of 

 tbe infection, consists in removing all such weeds and offal from the beets as 

 might help to shelter and nourish the parasites. The second plan, which aims at 

 destruction of the parasites, consists in the employment of lime, carbon bisulphid, 

 etc., and of the Kiihn method of trap-plants. It is believed that by these means 

 the injury may be greatly reduced, if not entirely prevented. 



A new method for combating' the sereh disease of sugar cane, T. Valeton, 

 Jr. (Teysmannia, 22 (1911), No. 12, pp. 767-772). — Attention is called to the 

 occasional resistance of certain varieties of cane to this disease, and the probable 

 value of breeding experiments to fix and extend these forms is discussed. 



A new fruit disease of eggplant, J. Hanzawa (Trans. Sapporo Nat. Hist. 

 Soc, 3 (1909-10), pp. 83-87, pi. 1). — ^A description is given of RJwMospcra 

 melongenw n. sp., a fungus that sometimes causes a severe rotting of the fruit 

 of the eggplant. 



Withertip of fruit and ornamental trees, E. Yoges (Deut. Landtc. Presse, 

 39 (1912), No. 2.'f, pp. 285, 286, figs. .'/). — An account is given of a disease of 

 twig ends of cherry, poplar, and other trees, resulting in their speedy death, 

 while neighboring twigs continue to appear healthy. Investigation revealed 

 the presence of certain fungi in the affected parts. Of these, 3, described 

 and illustrated, are said to be Nectria ditissima, Fusarium willkommi, and 

 Monilia cincren. 



Cement dust injury to fruit trees, P. J. Andekson (Ais. in Phytopathology, 

 2 (1912), No. 1, p. Ji5). — An investigation has been begun at the request of cer- 

 tain fruit growers to determine the effect of dust from cement mills. 



The dust was found to contain a high percentage of soluble calcium salt. 

 This dissolved in the stigmatic secretions and rendered them alkaline, and 

 pollen would not germinate in the alkaline solution. Artificial tests of the 

 pollen of cherries, pears, and apples gave no germination, even in very weak 

 solutions of the dust. Further tests showed that there was no germination 

 even when the calcium was not in an alkaline condition. 



Foliage diseases of the apple, H. S. Reed, J, S. Cooley, and J. T. Rogers 

 (Virginia 8ta. Bui. 195, pp. 23, figs. 13). — This bulletin is based on experiments 

 made during the years 1910 and 1911, the diseases investigated being the frog- 

 eye leaf spot, cedar rust, and apple scab as a foliage disease. 



The frog-eye leaf spot is said to be widely distributed and is probably due to 

 a number of fungi which produce similar appearances on the leaves. The varie- 



