194 PATHOLOGY [Bot. Absts., Vol. IV, 



1276. Doolittle, S. P., and W. W. Gilbert. Seed transmission of cucurbit mosaic by 

 the wild cucumber. Phytopath. 9: 326-327. 1919. — Seed from wild cucumber (Micrampelis 

 lobnla) affected with mosaic was saved in 1918 and planted in 1919. Thirteen out of 110 plants 

 developed mosaic. Cross inoculations to healthy plants resulted in the production of mosaic. 

 — R. E. Vaughan. 



1277. Dowson, W. J. Annual report of the mycologist for the year ending 31st March 1917. 

 Dept. Agric, British East Africa Ann. Rept. 1916-1917: 81-85. 191S. 



127S. Duggar, B. M., and Anne W. Davis. See disinfection for pure culture work; 

 the use of hypochlorite. Ann. Missouri Bot. Gard. 6: 159-170. 1919.— See Bot. Absts. 4, En- 

 try 1609. 



1279. Ehrenberg, P. Zur Frage der Beizung des Winterweizens gagen Steinbrand. [Dis- 

 infection of winter wheat seed against bunt.] Fiihl. Landw. Zeitg. 67: 425-432. 1918.— Smut 

 was so abundant in parts of Brandenburg that flour was ruined. — Experiments for control 

 were performed with "Uspulun" (Chlorphenol compound of mercury) as offered by Friedr. 

 Bauer & Co. 50 grams uspulun in about 8 liters of water sprayed over 100 kilos of seed; seed 

 covered for 7 hours, spread out to dry and seeded through disinfected machine. In one test 

 untreated seed gave 60 per cent smutted heads, treated, 21 per cent; in another, untreated 

 gave 17.8 per cent, treated 3.7 per cent. Results not entirely satisfactory. Possibly seed 

 should be dipped rather than sprinkled. The material would be easier to use if put out in 

 more concentrated form. — D. Reddick. 



1280. Esmarch. Uber den Wundverschluss bei geschnittenen Saatkartoffeln. [Wound 

 healing in cut seed potatoes.] Fiihl. Landw. Zeitg. 67:253-256. 1918.— See Bot. Absts. 4, 

 Entry 2410. 



1281. Ewart, A. J. The cause of bitter pit. Proc. Roy. Soc. Victoria (N. S.) 30 1 : 15-20. 

 1917. [Received in 1919.] — McAlpine's bursting cell theory and vascular interruption theory 

 in regard to the causes of bitter pit are discussed and refuted on the ground of data obtained 

 by the author and by Dr. White. The latter worker who advanced the view that bitter pit 

 is a symptom of slow local poisoning, also considers that it is not confined to fruits such as 

 apple and pear, but may occur in leaves and stems and may be produced artificially by the 

 direct application of poisons. The author cites also the occurrence of brown spongy patches 

 of dead tissue, unaccompanied by disease organisms, which are found in potatoes grown in 

 newly cleared acid soils, and also the disease known as "brown fleck" as possible further 

 instances of natural poisoning. A summary of the evidence in favor of the poison theory 

 of the origin of bitter pit is given. It is pointed out that every symptom of bitter pit can be 

 produced by the artificial application of poisons, including the typical occurrence of starch 

 grains in the dead cells. In apples sensitivity was very great. The poisoning may be oligo- 

 dynamic, i.e., it may occur in the presence of mere traces of poison. More bitter pit has been 

 found in heavily sprayed orchards than in those not thus treated. A close correspondence 

 between resistance to poison and resistance to bitter pit was noted. This holds also in rela- 

 tion to temperature effects. Both bitter pit and poisoning are retarded by low temperature. 

 In discussing the browning of bitter pit tissues it is pointed out that browning is due to the 

 addition of the oxidase, liberated from the dying protoplasm, upon the tannic acid of the cell 

 sap. Dfferent varieties of apples vary in the degree of browning. The differences in the 

 amount of tannic acid present are not sufficient to account for this. Testing with a dilute 

 solution of amidol showed marked differences in the amounts of oxidase present. It was sug- 

 gested that the oxidase content might serve to some extent to distinguish certain varieties of 

 apples. — Eloise Gerry. 



1282. Eyre, J. Vargas, E. S. Salmon, and L. K. Wormald. The ammonium polysul- 

 phide wash. Jour. Bd. Agric. Great Britain 26: 821-822. 1919. — Directions are given for the 

 preparation of a stable, concent rated solution of ammonium polysulphide containing as much 

 as 21.9 per cent of polysulphide sulphur. — .1/. B. McKay. 



