964 EXPERIMENT STATION RECORD. 



by small, definite, circular, greenish or j-ellowisii- white spots, varying 

 in size from mere specks to spots ^V in- or more in diameter. Fre- 

 quently a number of such areas occur upon the same leaf, and the 

 disease spreads until the entire leaf is destroyed. Various previous 

 theories as to the cause and treatment of the disease are discussed, and 

 the parasitic nature of it is shown hj the author's investigations, in 

 which artificial inoculations have been successfully made. The fun- 

 gus, which is a new species, is technically described, and the varying 

 susceptibilit)^ of difi'erent varieties is noted. Preventive measures 

 are suggested which contemplate the keeping of plants in a healthy 

 condition, propagating from only healthy, vigorous stock, as the best 

 possible means. The experiments conducted with fungicides seem to 

 show that they possess little value in preventing this disease, while 

 rendering the foliage worthless for bunching with the flowers. The 

 most practical means for preventing the disease appears to be in the 

 development of strong plants which are resistant to the attacks of the 

 fungus. 



An anthracnose and a stem rot of Antirrhinum majus, F. C. 

 Stewart {Science^ n. ser., 12 (1900), No. 303^ p. oSl). — A brief 

 account is given of two diseases of snapdragons — one an anthracnose 

 caused by a Colletotrichum, and a stem rot due to an undetermined 

 species of Phoma. The Colletotrichum produces elliptical depressed 

 spots on the stems and circular dead brown spots on the leaves, and is 

 very destructive to plants in both greenhouse and field, and at all sea- 

 sons. It was found due to a new species of fungus, to which the 

 name C. antirrhini was given. This disease may be successfully 

 combated by spraying the plants once a week with Bordeaux mixture. 

 The stem-rot disease attacks the stem, causing sections an inch or 

 more in length to turn brown or black. This attack may occur at 

 any point above the ground, and is usually observed a few inches 

 below the tops of succulent shoots. Inoculation experiments show 

 that the fungus is an active parasite of succulent shoots, ])ut attacks 

 woody stems with difiiculty. 



Experiments in the preparation of Bordeaux mixture, W. Kel- 

 HOFER {Jajii'ttihcr. Ifc-zw. ^St(d. u. >SchaU\ WddenHtccil^ 1SU7-98, ]>p. 

 57-68). — Experiments were conducted to ascertain the effect of a 

 number of factors upon the composition of Bordeaux mixture, as 

 shown by the separation of the difi'erent mixtures upon standing. 

 Among the experiments were those to determine the efi'ect of iron 

 sulphate, which is connnonly present in commercial coppei" sulphate; 

 upon difi'erent (juantities of copper sulphate; difi'erent (|uaiitities and 

 qualities of lime; different concentrations of mixtures; order of com- 

 bining the solutions; and temperature of solutions. The presence of 

 iron sulphate was found to cause a more rapid separation of the liq- 

 uid. Within the limits of the ex[)eriments, separation was inversely 



