1918.] FIELD CROPS. 525 



showing the presence of glaetosidase /3, which is thought to exist in all plants 

 containing lactase. 



The cause of growth in the hypocotyls of oat seedlings, Marie S. de Vbies 

 (Rec. Trav. Bot. N^erland., 14 (1917), No. 2, pp. 109-llS).— The author con- 

 cludes that hypocotyl development in Avena sativa occurs as the result of 

 evolution of carbon diosid. 



The department of plant physiology, B. E. Livingston {.Johns Hopkins 

 Univ. Circ, n. ser.. No. 3 (1911), pp. 13.3-159, figs. 2).— This paper, which deals 

 with the general aims of the department and the work accomplished therein 

 and which is intended to serve as a preface to the several preliminary reports 

 which follow, includes a bildiography of the work in plant physiology of Johns 

 Hopkins University during the 7J years previous to this report. 



The sexual cycle in plants, E. A. Bessey (Rpt. Mich. Acad. Sci., 18 (1916), 

 pp. 59-77, figs. 12). — In an address before the Michigan Academy of Science 

 the author discu.sses various theories regarding the development and signifi- 

 cance of the sexual cycle in plants. 



The hormone theory of chromosome action, E. A. Bessey (Rpt. Mich. Acad. 

 Sci., 18 (1916), pp. 5.3-.5S).— Reviewing the reasons for the belief that the 

 phenomena of heredity may be bound up with chromosomes, and, considering 

 the possible character of their activities and their probable bearing upon the 

 phenomena of heredity, the author subscribes to the belief that the chromosomes 

 may be the bearers of heredity. 



Hybrids of Zea tunicata and Z. ramosa, G. N. Collins (Proc. Nat. Acad. 

 Sci., 3 (1917), No. 5, pp. 3^5-349). — This article has been previously noted from 

 another source (E. S. R., 37. p. 5.36). 



A Hausa botanical vocabulary, J. M. Dalziel (London: T. Fislier Unwin, 

 Ltd., 1916, pp. 119). — The author has listed the Hausa names of many of the 

 more counnon plants of Northern Nigeria, giving the scientific name where 

 known, a brief definition of the plant, and in many cases an indication of its 

 native use and of its products. 



FIELD CROPS. 



The overhead electric discharge and crop production, V. H. Blackman and 

 I. JoRGENSEN (Jouv. Bd. Agr. [London], 24 (1917), No. 1, pp. 45-49, pis. 2, fig. 

 1; abs. in Nature [London], 99 (1917), No. 2481, pp. 232, 233).— lu continuation 

 of work previously noted (E. S. R., 37, p. 336), the effect of overhead electric 

 discharge on an oat crop during 1916 is reported. The electrified area was one 

 acre in extent and tv.'o plats of one-half acre each were used as controls. The 

 " earthed " screen of wire netting previously employed to insulate the control 

 areas was deemed unnecessary, the wires being kept low. The discharge was 

 applied by means of a series of 21 wires 4.5 yds. apart, running parallel to the 

 short sides of the rectangular area (88 by 55 yds.). The wires were supported 

 at a height of 7 ft. at each end, but sagged at the center to a height of 6 ft. The 

 current applied was practically the same as heretofore, but the intensity of the 

 discharge was much increased by the lowering of the wires, by reducing the 

 distance between wires, and by reducing the thickness of the wire (24 gauge). 

 The discharge was applied for 848 hours, extending over a period of 125 days. 



The yield secured from the electrified area amounted to 62.8 bu. of grain and 

 4,924 lbs. of straw, as compared with a total yield of 42 bu. of grain and 2,619 

 lbs. of straw from the control areas. The total increased yield was valued at 

 approximately $30.90, while the cost of the current was approximately $2.67. 



