630 EXPEBIMENT STATION RECORD. 



cau not be considered a plant nutrient. The nutrient effect of the various salts 

 was inappreciable when used in a less strength than 0.()2 per cent. The stimu- 

 lating effect of the salts was found to be of very short duration, after which the 

 resi)irator.v energy fell. 



The significance of the liberation of water vapor by plants, I>eclerc dit 

 Sablon {Rev. Gen. Bot., 21 (1909), No. 2-',8, pp. 295-311).— Some doubt having 

 been raised as to the importance of transpiration in the nutrition of plants, the 

 author reviews some earlier literature and presents additional data which 

 he believes indicate that the liberation of water vapor by plants has a far less 

 important role than that usually given it by plant i)hysiologists. 



In concluding his discussion the author claims that the absorption of mineral 

 salts by roots is independent of the absorption of water, and. as a consequence, 

 of transpiration, and is regulated by the osmotic power of each of the salts 

 occurring in the interior and the exterior of the plant. The utilization of these 

 salts by the plant, which causes them to go into insoluble combinations, is the 

 essential cause of tlieir absorption through the roots. 



An experiment by Scliloesing with tobacco showed that when there was a 

 considerable reduction of transpiration there was hardly any difference in the 

 absorption of salts and there was a tendency to an increase in the dry weight 

 of the plant. Transpiration is not necessary for the transportation of salts 

 from the roots to the leaves, nor is there any relation between the transpiration 

 and the formation of dry matter in plants. 



The stomata are organs for the exchange of gas in the respiration and as- 

 similation, and their physiological role and anatomical structure indicate that 

 they .'ire not for the escape of vapor, and that their function is to retain rather 

 than to liberate water vai)or from the plant. 



The occurrence of hydrocyanic acid in some mushrooms. M. Greshoff 

 (Pftarm. Weekbl. J,6 (1909). No. 51, pp. 1.',18-1J,25, fig. i).— Attention is called 

 to the occurrence of hydrocyanic acid in various mushrooms, and a number of 

 species are mentioned as giving the reaction to that substance. 



The mistletoe pest in the Southwest, W. L. Bray {V. fi. Dept. Afjr.. Bur. 

 Plant Indus. lUil. 1116, pp. 39. pis. 2, figs. 7). — This paper presents the results 

 of several years of investigation of the various phases of mistletoe parasitism, 

 together witli its history, development, germination, dissemination, and hosts. 



In combatting this parasite, it is believed that if the mistletoe is on small 

 branches pruning will suffice, but that when the branches are large and the 

 infected area is considerable the mistletoe should be cut out and the wounds 

 treated with an antiseptic paint or wash. Carbolineum proved especially effect- 

 ive for this purpose. 



Seeds and plants imported during the period from April 1 to June 30, 

 1909. Inventory No. 19 (U. i<. Dept. Agr.. Bur. Plant Indus. But. 168, pp. 

 Jj5). — This is a list with notes on the economic value of the seeds and plants 

 secured between April 1 and June .^>0. 1909. the number of introductions being 

 526. The li.st is made up of collections of seeds forwarded from correspond- 

 ents and cooperators throughout various parts of the world. 



FIELD CROPS. 



Experiment on the fertilizer requirements of meadows, P. Wagner (Arb. 

 Dcul. Landw. Gescll., 1909, No. 162, pp. 106; abs. in Mark Lane E.rpress, 103 

 (1910), No. Ji089, p. 139; Deut. Landw. Prcssc, 37 (1910), Nos. 29. p. 321; 30, 

 pp. 331, 332). — The author outlines in detail 16 different series of experi- 

 ments conducted at different points for from 4 to 9 years, reporting the 



