540 



SCIENCE 



[N. S. Vol. XXVII. No. 692 



turbed wave-len^h that the strength of the 

 disturbing magnetic field does to the field of 

 the atom itself. 



This gives at once the experimentally 

 established Zeeman law, that the change in 

 wave-length, divided by the strength of the 

 disturbing magnetic field times the square of 

 the undisturbed wave-length, is a constant; 

 and, by substituting known values for three 

 of the four terms, the magnetic strength of 

 the atom is found to be some thousands of 

 times that of the most powerful electromagnet. 



E. L. Earis, 

 Secretary 



THE BIOLOGICAL SOCIETY OP WASHINGTON 



The 440th meeting was held February 22, 

 1908, President Stejneger in the chair. 



Dr. B. W. Evermann read a paper on 

 " Testing the Water of Small Lakes for Oxy- 

 gen." The U. S. Bureau of Fisheries has for 

 several years been devoting a portion of its 

 appropriations to the physical and biological 

 survey of the streams and lakes of the states 

 and territories. 



These surveys have been directed primarily 

 to the securing of accurate knowledge regard- 

 ing the fishes and other animals native to each 

 stream or lake, the physical and biological 

 conditions under which they thrive, and the 

 fitness of the waters for other species whose 

 introduction is or may be proposed. 



Eecently, the bureau began the examination 

 of small lakes with particular reference to the 

 amount of absorbed oxygen contained in their 

 waters. Several such lakes have been exam- 

 ined in Wisconsin (in cooperation with the 

 Wisconsin Natural History Survey) and sev- 

 eral in northern Indiana. At Lake Maxin- 

 kuckee, besides dissolved oxygen, temperature 

 and depth, the determinations included titra- 

 tions for normal carbonates, bicarbonates and 

 free carbonic acid. The surface water for a 

 depth of a few meters was about air-saturated 

 with oxygen. Below six meters the oxygen 

 falls rapidly and at twelve or thirteen meters 

 disappears entirely from the water. The dead 

 plankton falling from the upper strata is suffi- 

 cient to keep the oxygen in the depths con- 



sumed by oxidation. Protection from storms 

 and winds which agitate the water is a factor 

 in the lack of oxygen in such lakes. 



Dr. C. Dwight Marsh referred to the effect 

 of wind in the distribution of oxygen in lakes. 

 While one class of lakes are shallow and hold 

 oxygen at all depths, and another are deep 

 and have no oxygen in the depths, there is 

 still a third class which are deep and yet con- 

 tain oxygen at their greatest depths. This 

 last class consists usually of lakes which by 

 their large size or exposure favor the creation 

 of bottom currents originating in the action 

 of wind, as by the piling up of water at one 

 end of the lake, and the subsequent return of 

 equilibrium. 



Mr. A. H. Howell read the next paper, 

 which was on " The Destruction of the Cotton 

 Boll Weevil by Insectivorous Birds." This 

 paper was based in part on Bulletins of the 

 TJ. S. Department of Agriculture and in part 

 on unpublished material. His subject was 

 illustrated by lantern slides and by the skins of 

 the weevil-eating birds. In reply to questions, 

 Mr. Howell said the cotton caterpillar, itself 

 an enemy of the cotton boll weevil, was eaten 

 and preferred to the latter by the birds, and 

 that the weevil, though a tough chitinous in- 

 sect, was probably digested within a few hours 

 in the stomachs of birds. 



Dr. Evermann said Mr. Howell's paper em- 

 phasized the necessity of international control 

 of migratory birds. The enactment of the 

 Shiras bill affecting birds, mammals and fishes 

 would be a step in this direction. 



The third paper was by Mr. E. V. Coville, 

 on "A Mistletoe Destructive to the Douglas 

 Eir." 



M. 0. Marsh, 

 Recording Secretary 



the botanical society of WASHINGTON 



The 46th meeting was held Eebruary 1, 

 1908. Vice-president 0. V. Piper presided 

 and thirty-five members were present. 



The first paper was by Mr. W. J. Spillman: 

 " Eive Types of Variation under the Chromo- 

 some Theory." Mr. Spillman started with 

 the assumption that the development of the 



