644 EXPERIMENT STATION RECORD. 



dead tissue. It disappears quite rapidly from dying- wood and the 

 cysts are never found in the dead portions of the vine. 



The use of sulpliur and copi)er has not been very effectual in check- 

 ing this disease, especially in the case of some of its foliar forms, as 

 the fungus is confined almost wholly to the inner i)arts of the host. 

 Causes tending to enfeeble the host are greatly exaggerated by this 

 disease, and its attack upon the i)rotoplasm in the inner parts will soon 

 kill the vine. 



The treatment recommended, especially for the chlorotic forms of the 

 disease, is the use of iron sulphate placed at the root of the stock, as a 

 wash to be used in autumn and winter, and in 0.5 to 1 per cent sohi- 

 tious as a spray to be applied to the leaves several times during the 

 growing season. 



Gladochytriwn viticolum is said by the author to x>roduce effects sim- 

 ilar to those of phylloxera where it causes discoloration s, and on this 

 account it should be considered in investigations relating to resistant 

 stock for grafting. 



A disease in the nurseries and plantations of Paris, T>. Mangin 

 {Compt. Bend., 119 {lt>94), Xo. IS, pp. ; 55-7.56).— The author describes 

 an attack of Nectrla cinnaharina under the name rouge, characterized 

 by the red or salmon colored elevations formed under the cortex. It 

 attacks linden, chestnut, maple, elm, locust, and ailantlms trees. The 

 last named has usually been considered free from attack, but the 

 author tinds it quite commonly diseased. 



Usually considered as a saprophyte, the parasitism of this fungus 

 has been shown by Mayr ' and veriiied by the author, who adds facts 

 as to the spore germination. The spores germinate very feebly or not 

 at all in water 5 sugar solutions are better, but wood infusions are the 

 best to use in cultures. The optimum temperature of germination of 

 the conidia is between 18 and 20^ C, and they are very sensitive to 

 light. Sodium naphthalate in 0.0005 per cent solution prevents their 

 germination, while 0.0003 solution of copper sulphate does not affect 

 them. Tannin in solutions of from 0.0025 to 0.004 per cent killed the 

 conidia. 



The infection of the trees is largely effected during the moist weather 

 of spring and fall, the hot, dry weather of summer and a low temperature 

 acting unfavorably upon the fungus. The living tissues offer consid- 

 erable resistance to the entrance of the parasite, and it must gain 

 access through wounds and dead wood. It is only after the mycelium 

 has ramified throughout the tissues and ejected their destruction that 

 the fruiting organs are formed. The effect of the fungus on the tissues 

 is rather characteristic. The starch is used up and greenish masses 

 deposited in the cells of the wood, resulting in a kiiul of gummosis 

 deposit in the vessels. In the cortex all the cellular portions are 

 broken down except the bast fibers. The cork alone resists the attacks 

 of the parasite. 



' Uutersucliungen aus dem forstbotauiscb. lust. Miinclien, vol. 3, pp. 1-14. 



