318 



SCIENCE 



[N. S. YoL. XL VI. No. 1187 



assembled, in recognition of the following 

 facts : 



1. The national and international need of 

 the maximum production of all food grains 

 for the immediate future. 



2. The preventable losses resulting from 

 smuts and other seed-borne diseases. 



3. Practical and simple methods of seed 

 treatment known to prevent such losses. 



4. The Office of Cereal Investigations has 

 already instigated a movement looking to the 

 more universal treatment of seed for the pre- 

 vention of these losses. 



Resolve: (1) That it is our conviction that 

 this work should be pushed with all possible 

 diligence. (2) That we as representatives of 

 these grain-growing states pledge to this work 

 our hearty cooperation and support. 



A committee consisting of Professor H. L. 

 Bolley, Professor M. A. Carleton, and Dr. L. 

 E. Jones, appointed to draft resolutions for 

 the extermination of the barberry bushes, 

 made the following report, which was ac- 

 cepted : 



In view of the vital importance of the 

 wheat crop, and as a national emergency meas- 

 ure likely to prove an effective aid in increas- 

 ing and insuring a better wheat crop in 1918, 

 be it resolved : 



That we, the cereal pathologists of the 

 American Phytopathological Society, in sum- 

 mer session assembled at Madison, Wisconsin, 

 respectfully ask the President of the United 

 States to appoint a commission to consider 

 the relation of the barberry to outbreaks of 

 black stem rust of wheat, barley, other cereals 

 and grasses with a view of deciding upon the 

 desirability of eradiction of all cereal rust- 

 bearing strains of the barberry in the United 

 States in order that this source of rust epi- 

 demics may be removed. 



Be it further resolved that the Secretary be 

 instructed to send a copy of this resolution 

 to the President of the United States. 



The following resolutions were also adopted 

 by the Conference: 



That the chairman of this body appoint a 

 committee to take up with federal authorities 

 the matter of securing some definite action 

 to insure an adequate supply of fungicides 

 and insecticides, particularly those containing 

 copper, for the protection of important crops 

 against the destruction of fungous diseases 

 and insect pests and to insure a reasonable 

 price for the same such as shall not be pro- 

 hibitory to their use by the farmers and fruit 

 growers of the United States. 



To THE Department of Plant Pathology 

 AND other Friends and Members of the Uni- 

 ^-ERSiTY OF Wisconsin : 



Whereas, the cereal pathologists in meeting 

 convened at Madison, Wisconsin, from July 

 9 to 11, were most hospitably entertained and 

 assisted at their third annual meeting; 



Resolved, that we extend our hearty thanks 

 and express our due appreciation for your 

 efforts in our behalf. 



The following officers were elected for the 

 ensuing year : Chairman, H. P. Barss. Secre- 

 tary, C. W. Hungerford. 



C. W. Hungerford, 



Secretary 



SPECIAL ARTICLES 



THE POSSIBLE ORIGIN OF THE TOXICITY OF 



ULTRA-VIOLET LIGHTi 



It is a general law of photochemical action 

 that only those rays are effective which are ab- 

 sorbed by the system in which the reaction oc- 

 curs.^ Visible light-rays are not, as a general 

 rule, selectively absorbed by protoplasm and 

 hence their action is usually confined to spe- 

 cialized pigmented areas which constitute the 

 receptive elements of optical sense-organs. 

 Ultra-violet light, on the contrary, is generally 

 highly toxic, even for colorless organisms, and 

 since this toxicity presumably depends upon 

 and is attributable to photochemical reactions 

 the question presents itself to which constitu- 

 ent of the protoplasm are we to attribute the 

 selective absorption of these rays which is the 

 necessary precedent of their photochemical ac- 

 tivity? 



It was pointed out nearly forty years ago by 

 Soret^ that the majority of proteins exhibit a 

 well-marked absorption-band in the ultra-vio- 

 let spectrum. In seeking for the origin of this 

 absorption-band Soret found that it is espe- 

 cially well exhibited by solutions of tyrosin, 



1 From the department of biochemistry and 

 pharmacology, Eudolph Spreekels Physiological 

 Laboratory, University of California. 



2 Eder, ' ' Handbuch der photographie, ' ' Halle, 

 1884, p. 28. 



» J. L. Soret, Arch. d. Sc. phys. et not. Geneva, 

 1878, pp. 322, 359; 1883, pp. 194, 204. A. d'Arson- 

 val, Arch, de Physiol. Norm et Path. Paris, 1890, 

 S6r. 5, T. 2, p. 340. 



