FIELD CROPS. 827 



Iiistillody, and oatacorolla which were crossed with uormal phmts. Tlie data 

 scriirod indicate tliat doniinance and recessiveness are not in any way atlribntes 

 of the factor or character in itself, bnt are the resnlt of tlie factor expression 

 phis the modifying; inflnence of tlie environment. 



Notes on root variation in some desert plants, W. A. Cannon {Plant 

 World, 16 (1913), Ko. 12, pp. 323-341, figs. //).— Reporting stndies on a number 

 of desert plants, the author states in substance that root systems of desert 

 perennials may be roughly chissed as generalized or specialized. The former, 

 as in case of FruuHcria diimosa, are capa])le of greater variation than the 

 latter, such as cacti. Under cultural (garden) conditions Opuntia arhuscula 

 and O. ncoarhitscula were not modllied by an unaccustomed depth of soil and 

 water, as were, however, O. }<pinosior, O. vivipara, and O. disrata. Variations 

 were experimentally induced as to length of roots in a number of plants named, 

 grown in tubes, the roots of all these showing increase in length. 



PIELD CROPS. 



Growing crops and plants by electricity, Miss E. C. Dudgeon (London, 

 [1913], pp. VI II -{-36, figs. 12). — The author reviews briefly some work of other 

 investigators on this subject and gives some results of her o^^^l experiments. 



Potatoes grown under electrical influences in the field produced from 12 

 cwt. 12 lbs. to 2 tons 4 cwt. per acre more than those grown on the control plats. 

 " It is also evident that some crops respond to the treatment better than 

 others; in all the experiments there has been a distinct advance in the per- 

 centage of wheat, in potatoes the returns vary considerably, with a few excep- 

 tions leguminous plants are adversely affected, but a curious point in con- 

 nection with these plants is that grown in rotation they have an opposite effect 

 upon the soil to cereals." 



Experiments with the mercury vapor lamp in the greenhouse on the germina- 

 tion of French beans, carrots, cauliflowers, lettuce. Maple peas, oats, barley, 

 and wheat showed a shortening of the germination periods ranging from 5 to 

 20 days. Filbasket peas matured 8 days earlier under the mercury vapor lamp 

 than in the control pots. 



Experiments on the influence of electricity upon plant growth, W. 

 ScHiKORRA (Mitt. Kaiser WiUiclms Inst. Landir. Bromhcrg, 5 (1913), Xo. 5, 

 pp. 403-411, fig. 1). — In this article the author discusses the work of other 

 investigators and gives some results of his own experiments with pot cultures. 

 The method of applying the electricity is fully described. The current, ."iS.OOO 

 to 40,000 A'olts, is taken from a machine and made to jump a distance of 15 cm. 

 from a copper wire point suspended over each pot to an upright copper wire 

 point in the center of the pot. 



The results of connecting the suspended point with either the positive or 

 negative pole showed an injurious effect of the current on rye and winter 

 barley when applied during a period of from IG to 20 days at intervals amount- 

 ing to a total of from 42 to 51 hours. The decrease in yields amounted to from 

 11.3 to 14.8 per cent. 



In another experiment in which the charge received by the pots was reduced, 

 rye showed an increase of 0.4 per cent and winter barley an increase of 11.6 

 per cent in yield after a jieriod of 70 days, during which the treatment occurred 

 for a total of 243 hours. When the copj^er ix>ints in the pots were removed, 

 barley showed an increase of 8.9 per cent and oats of IG.l per cent in yield 

 of dry matter over no treatment. 



The experiments descril)ed above were carried on in an inclosed room. When 

 tlie work was transferred to the open, the atmospheric moisture interfered with 



