FIELD CROPS. 961 



pp. 296-301). — The author has successfully examined, isolated, and cultivated the 

 microorganisms growing in the root tubercles of red, white, bur, and Bweel clover, 

 garden peas, and alfalfa, and tin- results obtained have been bo satisfactory that be 

 gives a detailed accounl of the methods pursued. 



Directions are given for the selection of the tubercles, methods of treatment, and 

 transfer to nutrient media. The author prefers the slightly alkaline Bolid media of 

 beef extract, salt, gelatin, and agar, only sufficient agar being used to give solidity. 

 The directions for preparing tubes and their inoculation, as well as for plating the 

 contents of the inoculated tubes, are given in detail. < me reason for apparent fail- 

 ure in the culture of these organisms is believed to be the fact that the morphological 

 characteristics arc entirely changed, so that there is little similarity between the 

 organism as it appears in the tubercle and thai appearing in the artificial culture 

 media. 



The delta of the Rio Colorado, I>. T. Macdougal I Contrib. A. ) . Bot. Gard. t 

 1906, No. 77, ]>/>. 16,fig8. 6, m><i> t). — The physical and topographical features of the 

 region are described, after which the author gives lists of the plants found and their 

 uses, and discusses briefly the agricultural possibilities of the region through the 

 extension of irrigation. 



The poisonous plants of Indiana, S. Coultbb I Proc. Iml. Acad. ScL, 1904, />/>■ 

 51-63). — A list is given of a large number of species of plants that are reputed to be 

 poisonous by contact, the species heing embraced in about 40 genera and many dis- 

 tinct orders of plants. The author has been led to doubt the poisonous action of 

 many of the plants, and he has conducted investigations with fresh material of all of 

 them as far as available, and as a result has greatly reduced the number of plants 

 which are known to be contact poisons. 



The poisonous plants may be readily separated into two groups. In one tin- .-kin 

 irritation is due to the action of some specific substance of the plant, while in the 

 other it is mainly due to mechanical causes. The method of experimental study 

 was to handle the plants freely, and if after some days no results were apparent, the 

 part of the plant said to contain the poisonous element was rubbed upon the hack 

 of the forearm until serum, and at times blood, exuded, the juice of the plant and 

 the serum being allowed to dry upon the arm. If no results followed it was consid- 

 ered safe to infer that the plant was not a contact poison. 



Detailed results are given of the investigations of the different species enumerated 

 in the list, and in conclusion the author states that the great majority of the plants 

 included in the list are harmless under ordinary handling. Some may act as skin 

 irritants as the result of prolonged application or unusually rough handling. Care- 

 ful washing after handling any of the forms will reduce the danger to a minimum. 



The species found to be definitely contact poisons, arranged in order of their viru- 

 lence, are Rhus vernix, Jl. radicans, Euphorbia coroUata, Cypripedium hirsutum, Anthe- 

 inis cotula, Erigeron [Leptilori] canadense, CU matis virginiana, and Bidens frondosa. 

 This list does not include the nettles or a number of forms which poison under 

 unusual conditions, such as grinding, powdering, or long-continued application. Of 

 the plants mentioned above, the two species of the genus Elms are the only ones 

 which affected all the experimenters. The greater number of the plants experi- 

 mented with proved absolutely harmless under all conditions of experiment. 



FIELD CROPS. 



Results obtained in 1905 from trial plats of grain, fodder corn, field roots, 

 and potatoes, W. and ('. E. Sai NDEBfl {(_'<ut<t<ht Cut. Expt. Farm Bvl.6SfPp.48). — 

 The results secured in 1905 in variety tests with the different held crops conducted 

 for the past 11 years on uniform trial plats are given mainly in tabular form. The 

 reports for earlier years have been previously noted | E. B. K., lt>, p. 961). 



