254 



SCIENCE 



[N. S. Vol. XXXII. No. 816 



I am not as yet prepared to give an answer. 

 As intimated in my report of the Inter- 

 national Seismological Association, a special 

 committee has been appointed to investigate 

 this particular point. 



We may sum up then the conclusions so far 

 arrived at: 



1. Microseisms are essentially due to 

 meteorological phenomena, that is, to baro- 

 metric pressure and the accompanying gradi- 

 ents. 



2. The amplitude of microseisms is largely 

 a function of the steepness of the barometric 

 gradient. 



3. Areas of low barometer with steep gradi- 

 ents, but west of Ottawa have little effect in 

 producing microseisms. 



4. Strong microseisms are almost invariably 

 accompanied by steep gradients in the Gulf 

 of St. Lawrence, with the St. Lawrence val- 

 ley, containing the Great Champlain Fault, 

 on a line of steep gradients. 



5. A well-marked low sweeping up the At- 

 lantic coast from Florida to Newfoundland 

 is almost always accompanied by marked 

 microseisms. 



6. Microseisms are but slightly, if at all, in- 

 fluenced by the movements of lows across 

 the continent. 



7. Microseisms are not produced by local 

 winds, frietional excitation of the earth's sur- 

 face. 



8. Microseisms represent vibrations in vast 

 blocks of the earth's crust, covering tens of 

 thousands of square miles; and the period is 

 possibly dependent on or modified by marked 

 geological configuration and depth. 



9. Microseisms once produced may continue 

 for some time when the immediate cause has 



To the above may be added that, as the 

 microseisms are mainly dependent on the 

 action of the low on the ocean, and as at 

 Ottawa they are recorded after the low 

 passes, the reverse should be the case in 

 Europe, where the ocean is to the west, and 

 the low passes over it before reaching the 

 continent. 



Otto Klotz 



SOCIETIES AND ACADEMIES 



THE IOWA ACADEMY OF SCIENCE 



The sessions of the Iowa Academy of Science 

 were held in the zoologieal lecture room in Blair 

 Hall, Iowa College, Grinnell, beginning at 1:30 

 P.M., Friday, April 29. 



The public address by Professor William A. 

 Noyes, of the University of Illinois, on ■' A Scien- 

 tific Revolution," was given Friday at 8:00 P.M., 

 in the college chapel. 

 The Digestibility of Ble<jched Flour: E. W. 



ROCKWOOD. 



The Effect of Continued Gririding on Water of 

 Crystallization: Nicholas Knight. 



A Study in the Determin/ition of Calcium : Geobge 

 W. Heise. 



A Notice on the Cast Iron Casing in Well Four 

 at Grinnell: W. S. Hendbixson. 



Tfce lotcxi Lakeside Laboratory (illustrated) : R. 



B. Wtlie. 



A brief account of the first session of this 

 biological laboratory, summer, 1909, with lantern 

 slide illustrations of the grounds, buildings and 

 points of interest near the station. 

 The Flower of Elod-ea (illustrated) : R. B. Wtlie. 



Details of an undescribed type of staminate 

 flower, which at maturity elongates similarly to 

 the pistillate flower of this genus. 



Prelimitvary List of the Parasitic Fungi of Fayette 



County, loioa: Guy West Wilson. 



The results of field work in this region since the 

 autumn of 1907 are embodied in this paper. 

 While the number of species found is quite large, 

 and many of them of no small interest, further 

 field work will greatly augment the list. This is 

 especially true of the Jung Imperfecti, which have 

 been least thoroughly studied. 

 Prairie Openings in the Forest: B. Shimek. 



A discussion of the prairie flora of these open- 

 ings, and of the conditions which cause its appear- 

 ance. 

 The Influence of Air-currents on Transpiration: 



Miss Maud A. Ekown. 



An account of the results of laboratory experi- 

 ments showing the effect which currents of air of 

 various velocities have on transpiration. 



Delayed Germination: L. H. Pammel and Char- 

 lotte M. King. 

 For some years we have made a study of the 



germination of weed seeds under different coudi- 



