why this is more true of separate traits than of the organism as a whole, or how the theory is affected by modern work in experimental genetics. Indeed, the occurrence of mutations makes it easier to understand the results of natural selection, for the larger variations may have a definite value to the species when the smaller variations which might have lead up to them would not.
In his second address Professor Bateson says that at every turn the student of political science is confronted with problems that demand biological knowledge for their solution, but it does not appear that most of Professor Bateson's own generalizations—whether correct or not—are based on genetic research. For example, he urges that it can not be granted without qualification that the decline in the birth-rate of the intelligent and successful part of the population is to be regretted. He says that if the upper strata of the community produce more children than will recruit their numbers, some must fall into the lower strata and increase the pressure there. But it is by no means certain that there is too great pressure of population in France, Germany, England and the United States, and it would seem that an increase of intelligence and energy in the so-called lower classes would be a gain.
In so far as the small birth-rate of the upper classes is not so disastrous as some authors urge, it is because these classes owe their position to privilege rather than to ability, and if the privileged classes do not produce enough children to fill the positions of influence, men of greater ability may be found.
Professor Bateson says: "Modern statesmanship aims rightly at helping those who have got sown as wildlings to come into their proper class; but let not any one suppose such a policy democratic in its ultimate effects, for no course of action can be more effective in strengthening the upper classes whilst weakening the lower." Here and elsewhere Professor Bateson seems to misunderstand the proper meaning of democracy, which is not that all individuals are equal, but that each should have opportunity according to his ability.
A COMPREHENSIVE STUDY OF A DESERT BASIN
The making of the modern Salton lake in the sink of the Cahuilla basin in 1905 and 1906 was due directly to the opening of canals for irrigation from the Colorado River leading into the bowl and a coincidence of flood water from the main tributaries of the river. The director of the Desert Laboratory of the Carnegie Institution, Dr. D. T. MacDougal, formulated a plan for systematic measurement of the various physical and biological changes accompanying the recession of this lake and the results of the activities of the members of the staff of the Desert Laboratory and other collaborators are given in Publication 193 of the Institution.
Scarcely had the level of the lake begun to fall and the salts to become more concentrated, when it was noted (in 1911 that calcium was being lost from a solution not near the saturation point for carbonate, and in 1911 a distinct coating of lime was recognized on the branches of submerged trees. Such deposition seemed to be associated with the activities of certain bacteria and algæ, and to constitute the first stage in the formation of the travertine left by previous lakes. Investigation of this matter is still in progress, as well as that of the disappearance of potassium from the lake water which is now plainly apparent. The principal changes in plant tissues submerged in the Salton were studied by President M. A. Brannon, of the University of Idaho, who found bacteria of the Amylobacter group were present, which produced a hydrolyzing action on the unlignified uarts of vegetable tissues. Coincidently, Professor G. J. Peiree, of Stanford University, followed the behavior of some of the organisms which endure the entire range of variation from fresh to brackish water and finally to brine in
