22 EXPERIMENT STATION RECORD. 



Combating field mice, wood mice, and house mice by means of liOffler's 

 bacillus of mouse typhus, K. Kornauth {Ztsclir. Landir. ]\'rsiieli>!ir. OrMerr., S 

 {1900), No. 2, pp. 123-132). — The laboratory methods for preparing jnire cultures of 

 this bacillus have been much improved and it is now possible to distribute cultures 

 of a more uniform virulence and at a smaller price. During 1899, 20,471 agar cultures 

 of this bacillus were distributed in 468 localities. Circular letters of inquiry con- 

 cerning the effectiveness of these cultures were sent to 324 persons, and satisfactory 

 replies were received from 214. Of the 115 replies which referred to Held mice, it 

 was stated in 71 cases that the action of the cultures was good, while about 15 per 

 cent of the replies stated that the cultures had no effect. Of the 24 replies which 

 referred to wood mice, 18 reported good effects; and of the 73 relating to house mice 

 57 reported good results. A detailed statement covering the statistics relating to 

 these agar cultures is presented in tabular form. The author states tiiat the distri- 

 bution of cultures was made late in autumn, and therefore at a time of the year 

 when the disease was less apt to spread rapidly than in the spring. 



The feathered denizens of the orchard, O. Widmann {Missouri State Hort.Soc 

 Rpt. 1900, pp. 146-156). — Brief notes on the biological relations of woodpeckers, 

 sapsuckers, chickadees, wrens, and other common birds. 



The insectivorous birds of Western Australia, R. Hall (.Tour. Drpt. Agr. 

 West. Auxtr<di<i, 2 (1900), Xo. 6, ]>p. 3S8-397, ,ti<js. 3; 3 {1901), Xo. 1, pp. 18-23, 

 fig. i).^Brief notes are given (::n the feeding habits and' biology of martins, swifts, 

 swallows, and wood swallows. 



The food of the variegated crow (Corvus cornix), G. Staes (Tijdschr. Plan- 

 tenziehten, 6 (1900), Xos. 1, pp. 12-22; 3-4, pp. 98-105).— X critical review of the 

 literature of the subject, together with a brief summary of the results thus far 

 obtained from the study of the feeding habits of this bird. 



METEOROLOGY. 



The eclipse cyclone and the diurnal cyclones, H. H. Clayton {Proc. Amn: 

 Ac(i(J. Art.'t and Sri., 36 (1901), Xo. 16, j>p. 307-318, figs. 6). — This article sununarizes 

 the results ot meteorological observations on the solar eclipse of May 28, 1900. The 

 meteorological effects of the eclipse are shown to be important, because (1) they con- 

 firm Ferrel's theoiy of the cold-air cyclone, and show (2) the wonderful rapidity 

 with which cyclonic jjhenomena can develop and dissipate in the atmosphere, and 

 demonstrate (3) that cyclones do not necessarily drift with the atmosphere, but move 

 with their originating cause, which in the eclipse had a i>n)gressive velocity of about 

 2,000 miles an hour. 



"The discovery that the brief fall of temperature attending a solar eclipse produces 

 a well-develoi^ed cyclone which accompanies the eclipse shadow at the rate of about 

 2,000 miles an hour suggests that the fall of temperature due to the occurrence of 

 night must also produce or tend to produce a cold-air cyclone. Since the heat of day 

 produces or tends to produce a warm-air cyclone, there must tend to occur each day 

 two minima of pressure, one near the coldest part of the day and another near the 

 warmest part of the day, with areas of high pressure between them due to the over- 

 lapping of the pericyclones surrounding the cold-air and the warm-air cyclones, respec- 

 tively. These causes must produce entirely or in part the well-known double diurnal 

 period in air pressure. At any rate, in view of the fact that an eclipse causes a cyclone 

 over half a hemisphere, it will be necessary before rejecting such a theory to show 

 that the fall of temperature at night does not produce a cyclone, or that this cyclone 

 and the corresponding warm-air cyclone of the daj' do not appreciably influence the 

 barometer." 



The points in favor of the theory that the double diurnal j^eriod in pressure is due 

 to 2 diurnal cyclones, one developed by the cold of night and the other by the heat 

 of day, are briefly stated. 



