858 EXPERIMENT STATION RECORD. 



greater resistance to poisons tban do any of the other fungi investi- 

 gated. Uromyces does not diminish in vigor of growth with the increased 

 strength of the poisons, but it does diminish in the percentage of spores 

 which germinate. 



Influence of wet weather upon parasitic fungi, B. D. Halsted 

 (Proc. Amer. Assoc. Adv. Sci., 47 (1898), pp.- 116). — The author states 

 that there is apparently some connection between weather and the 

 occurrence of parasitic fungi. During 1898 the month of May was 

 remarkably wet and the following June brought an abundance of para- 

 sitic fungi. Among these were the rusts of hollyhock, cedar, and man- 

 drake; smuts of lily, spring wheat, and oats, and peach leaf-curl fungus. 

 It is stated that the year 1889 was noted for its wet summer and also 

 for the destruction of potatoes by rot. In 1897 July was phenomenal 

 for its heavy precipitation, 11.42 in. This was followed by a serious 

 outbreak of potato rot, causing a wholesale destruction of the tubers. 

 Phytophthora phaseoli was discovered in the wet summer of 1889 and 

 reappeared destructively in 1897. The records of the New Jersey 

 Station show that both the wet years mentioned were noted for the 

 abundance of black rot of grapes and rust of apples. In 1894 the grow- 

 ing season opened with a wet May and closed with a rainy September. 

 There were long periods of cloudy weather and often it was hot and 

 showery. This year witnessed an unprecedented outbreak of fire blight 

 of apple, quince, and pear. In 1890 there was a rainy June and July 

 and during this period the asparagus rust made its appearance in the 

 eastern United States to an alarming extent, and in 1897 it was even 

 more abundant. "There are not sufficient data for safe and substantial 

 generalizations, but heavy rainfalls in spring seem to induce rusts in 

 grains and orchard and garden crops, and the fire blights of fruit trees. 

 Midsummer precipitations favor the decay of fruits, particularly the 

 stone fruits, and the rotting of potatoes. Rainfall does not express all 

 the meteorological conditions that need to be taken into consideration 

 in this connection." 



Concerning the etiology of some diseases of cultivated plants, 

 P. Caevaka (Staz. Sper. Ayr. Ital., 30 (1897), No. 0, pp. 482-507).— The 

 author gives extended observations upon what he terms the tuberculo- 

 sis of the grape, necrosis of grape stems and shoots, necrosis of mul- 

 berry, and tuberculosis of the peach. All these diseases are said to be 

 of bacterial origin. The author claims to have isolated the organisms, 

 cultivated them on artificial media, and produced the diseases by inocu- 

 lation from cultures. 



Tuberculosis of the grape is said to greatly resemble olive tuberculo- 

 sis, but may be distinguished by the greater number of small tubercles. 

 These tubercles form in groups under the periderm, causing protuber- 

 ances, resulting in the breaking of the cortex. This takes place espe- 

 cially near the nodes bearing the bunches of grapes, and when the vine 

 becomes old the branches are nearly surrounded by them. The affected 



