218 THE AMERICAN MONTHLY [September, 



Bureau of Ethnology," for 1884-85, and " The Seventh Annual Re- 

 port of the Geological Survey," i885-'86. 



A donation of fossil diatomaceous deposits was received from 

 P. Klavsen, Odense, Denmark, and with them a small quantity of 

 recent diatoms from Odense Fjord. 



William Payzant exhibited fresh-water polyzoa from Lake Temescal, 

 Berkley, of the genus Plumatella^ specific name undetermined. In 

 this is the first find of Plumatella in this vicinity. Nothing could have 

 been more beautiful than the expanded tentacles, gently waving in the 

 drop of water. 



July g. — Among the visitors present were Dr. Gustav Eisen, of 

 Fresno ; M. H. Burnham, Prescott, Ariz., and W. M. Cubery, of this 

 city. 



President Wickson exhibited leaves of the cultivated blackberry 

 afflicted with a red rust, a fungus growth — Uredo ccepma nitens. These 

 leaves were sent by C. S. Upham, Moore's Station. This fungus is 

 common on the wild blackberry leaf and on some other plants. This 

 plant in its general characteristics and mode of growth is quite like 

 the rust of wheat, or the rust on the rose leaf. Hybrid perpetual roses 

 are especially susceptible to its attacks. The Government experts in 

 mycology have recommended spraying roses or other bushes thus in- 

 fected with a very weak solution of ammoniated sulphate of copper — 

 a solution of common blue-stone with a little w^ashing ammonia added. 

 Six cents' worth of ammonia and sulphate of copper makes twenty-two 

 gallons of solution of sufficient strength to destroy the fungus, and it 

 has been noted that the sulphate of copper is of no avail unless the 

 ammonia is also added. 



Dr. Eisen mentioned, during the discussion, the vine disease of 

 Southern California, and the destruction it had wrought. This disease 

 has been studied by N. B. Pierce, who says it is caused by the presence 

 of bacteria. Some of the sap of diseased vines was used to inocu- 

 late healthy vines Soon all the symptoms and conditions of the dis- 

 ease were noted in these vines, and the bacteria were found in large 

 numbers in the cells. Dr. Eisen and Dr. Mouser were of opinion that 

 further investigation would demonstrate that other causes than bacteria 

 were responsible for the ravages of the disease. The juice of grapes 

 grown on vines thus infected is very bitter and unpleasant to the taste, 

 so there is little likelihood of the same entering into human food. A 

 further peculiarity of this vine disease is that apricot and fig trees grown 

 near an infected vineyard also show symptoms of the disorder. 



Mr. Riedy exhibited a diatom slide prepared by Thum, of Leipzig, 

 containing 300 difterent species of diatoms, arranged in lines and 

 squares and accompanied bv a manuscript catalogue giving the specific 

 and generic name of each. The diatoms were arranged after the sys- 

 tem in Dr. H. Van Heurck's Synopsis des Diatomees de Belgique; 

 and when it is considered that the 300 forms on the slide occupied a 

 space only four millimeters square, and each individual frustule was 

 correctly placed as to its position in the lines and squares, the manipu- 

 lation necessary to this arrangement is simply a marvel. 



R. H. Freund exhibited a slide of micrococci which revealed a 

 large number of forms. 



