92 proceedings: Washington academy 



mathematics. Mathematics is only an instrument. Kelvin appealed 

 to observation, some others used mathematics to reach their conclusions. 

 We should cultivate the principle of relativity, and in doing this it was 

 predicted that our earlier views would prove to be but first approxi- 

 mations. That matter is essentially atomic, and that ether can be 

 placed in the same category, which was also Lord Kelvin's view, is the 

 greatest advance in the last twenty years. 



A joint meeting of the Botanical Society and the Washington Acad- 

 emy of Sciences was held on the evening of November 14. Prof. W. 

 Johannsen, of the University of Copenhagen, was introduced by Presi- 

 dent Clarke and spoke upon Heterozygosis in pure lines of beans and 

 barley. 



He began by stating that the title of the paper being technical might 

 possibly not be understood by those unfamiliar with the nomenclature 

 applied to cross-breeding in plants and animals. The essential sexual 

 element of an individual is called agamete. These unite forming zygotes. 

 A zygote is therefore a dual being. When these zygotes are like the 

 parent gamete they are called homozygotes, when different heterozy- 

 gotes. Heterozygosis may therefore be defined as mixed interbreeding. 



Two flowers may look alike but give rise to offspring quite different in 

 appearance. These different forms serve to show the latent characters 

 existing in the parent and inherited from previous ancestors. There 

 appear to be influences at work here which resemble the affinities shown 

 in some chemical compounds. 



A pure line is one that produces homozygotes. There are apparently 

 chemical laws at work here but what they are we at present but dimly 

 surmise. 



The lecturer illustrated his remarks by reference to diagrams showing 

 the effect of crossing certain strains of beans, barley, snails, etc. 



In commenting upon the lecture President Clarke said that the ques- 

 tion of the coloration of flowers was doubtless a chemical phenomenon 

 and that the intimate study of the chemistry of these compounds will 

 probably yield some results. As to how chemical substances or reac- 

 tions can influence form we are at present almost entirely in the dark. 



Mr. McDougal said that the work in a botanist's laboratory was neces- 

 sarily limited, more definitely than actually occurred in nature as he 

 could perform artificial selections at will. Doubtless mechanical as 

 well as chemical factors are at work to produce the varied forms of off- 

 spring. These were the problems which the modern physiologist has 

 to face. Frank Baker, Secretary. 



THE BIOLOGICAL SOCIETY OF WASHINGTON 



The 489th regular meeting was held at the Cosmos Club, December 2, 

 1911, with President David White in the chair. 



Under the head of Brief notes and exhibition of specime?is, General 

 Wilcox told of finding many pieces of white quartz in the stomachs of 

 the blue grouse. 



