340 EXPERIMENT STATION RECORD, 



tions, exploitation, management, and financial results for the year. All of the 

 important data are presented in tal)ulav form. 



Progress report on forest administration in the Punjab for 1907-8, C. P. 

 Fisher {Rpt. Forest Admin. Punjab, 1907-8, pp- 15+XLI+VII). — Data similar 

 to the above are presented relative to the constitution and management of State 

 forests in the Province of Punjab. 



Palo amarillo rubber, P. Olsson-Seffer (Daily Cons, and Trade Rpts. 

 [U. 8.], 1909, No. 3516, pp. 1, 2). — The author discusses the probable importance 

 of the palo amarillo tree [EiipJiorbia fulva) as a rubber yielding species. This 

 tree, which is a hitherto botanic-ally unknovi^n species, occurs in the dry, semi- 

 tropic zone on the slopes of the Sierra Madre in Mexico, and has recently been 

 exploited as a desirable source of rubber. 



Chemical examination of the latex shows it to contain from 7.3 to 15.7 per 

 cent of rubber and from 19 per cent upward of resins. The latex from the 

 lower parts of the trunk is richer in rubber, the rubber content of the latex 

 from the branches being only from about 3 to 6 per cent. The author is of the 

 opinion that, although the palo amarillo tree can be commercially exploited, the 

 entire supply of the tree is too small to warrant the exaggerated estimates sent 

 out by certain pi-omoters. The resulting rubber is classed as about similar in 

 quality and value to guajule rublier. 



DISEASES OF PLANTS. 



Plant pathology, \. Ducomet ( Botaniqitc agricolc. Pathologic Vcgctale. 

 Paris, 190S, pp. X-r298, figs. 21). — This book treats of the fungus and bacterial 

 diseases of plants and is one of the agricultural series published under the 

 direction of J. Dumont. After a general discussion of parasitism and sapro- 

 phytism, the author describes fungus parasites and their effect on the host, 

 predisposition to disease, and resistance, after which a number of the more 

 prominent fungus and bacterial diseases of plants are describe<l and suggestions 

 given for their control. 



A new method of combating parasitic diseases of plants, M. C. Potter 

 iCenthl. Bait, [r/c], 2. Aht.. 2.3 {J90H), Xo. tO-U3, pp. 379-38'i, flg. /).— This 

 is essentially the same as an article already noted (E. S. It., 2<>, p. 11.37). 



The toxic action of Bordeaux mixture and of certain solutions on spores 

 of fungi, J. B. Dandeno {Rpt. Mich. Acad. Hci., 10 (1908), pp. 58-62).— The 

 object of the experiments reported was to determine the resisting power of 

 some of the common forms of fungi to certain toxic solutions and also to Bor- 

 deaux mixture. The following species were used : PcniciUium glaucnm, Puccinia 

 asparagi, Macrosporiuiii nobilc, Ustilago maydis, and Glomcrclla rufomaculans. 

 The chemicals tested were caustic soda, caustic potash, hydrochloric acid, sul- 

 phuric acid, copper sulphate, and Bordeaux mixture. All these substances, ex- 

 cepting the last, were used in fractions of normal solutions. The test made was 

 to determine whether the spore was able to germinate and send out a hypha 

 while actually immersed in the liquid. 



The results obtained show a number of rather remarkable apparent para- 

 doxes. The spores of Macrosporium were much more injured by solutions of 

 hydrochloric than of sulphuric acid, while the reverse appears to be the case 

 with the spores of Ustilago. The spores of all the fungi, and pai'ticularly 

 Ustilago and Macrosporium, proved very resistant to solutions of copper sul- 

 phate. Caustic potash and caustic soda did not show any results of great 

 importance, although the caustic potash appeared more toxic than the soda 

 solution. 



