Maech 23, 1900.] 



SCIENCE. 



455 



specific or subspecific value to differences 

 which are due merely to some slight differ- 

 ence in environment. This, it seems to me, 

 misses the whole point. What produces 

 species and subspecies, anyway, except 

 slight differences in environment, together 

 with greater or less geographic isolation ? 

 And when we see these differences why 

 should we refuse to admit their existence or 

 their meaning? 



Barton W. Evbrmanist. 

 "U. S. Commission of Fish and Fisheeies. 



BREATHING OXYGEN. 



The experiments here described were 

 carried out during the course of an investi- 

 gation to determine the quantity of carbon 

 dioxide exhaled from the lungs of different 

 persons under stated conditions. 



The method of procedure was as follows : 

 (1) Ordinary air was inhaled through the 

 nostrils and exhaled through the mouth 

 (the nostrils being closed) into an inverted 

 receiver filled with water. The quantity of 

 carbon dioxide in the exhaled gases was de- 

 termined in the usual manner. (2) A mix- 

 ture of air and oxygen containing 26.4 % 

 of oxygen was inhaled and exhaled as in 

 (1). (3) Pure oxygen was employed and 

 the experiments conducted as in (1) and 

 (2). 



The breathing experiments were made by 

 three different persons, A, B, and C, under 

 conditions as nearly indentical as possible. 



The following results were obtained : 



Exp. 



5-1 f- Ordinary air. 



5.4 (■ Air and oxygen. 



5.8 >- Pure oxygen. 



The figures given express percentages by 

 volume ; they are lower than those that 

 would be obtained if the exhaled gases 



were collected over water saturated with 

 carbon dioxide. The object of the exper- 

 iments was to get relative rather than 

 absolute values. In experiments 1, 4, 7, 

 10, 13, 16, 19, 22 and 25, the gas (air, 

 mixture of air and oxygen, or oxygen) was 

 inhaled for five seconds and then exhaled 

 for five seconds. 



In experiments 2, 5, 8, 11, 14, 17, 20, 23 

 and 26 the lungs were inflated as fully as 

 possible with the gas, which was retained 

 fifteen seconds and then exhaled. 



In the other experiments, 3, 6, 9, 12, 15, 

 18, 21, 24 and 27, the lungs were fully in- 

 flated and the gas retained tliirty seconds 

 before exhalation. 



William B. Schobee. 



Lehigh University. 



THE SOCIETY OF AMERICAN BACTERIOL- 

 OGISTS. 

 The following are abstracts of papers read 

 at the first meeting of the Society of Amer- 

 ican Bacteriologists, held at ]S"ew Haven, 

 December 27 th to 29th. 



Natural varieties of Bacteria : Professor H. 



W. Conn. 



Professor Conn exhibited some cultures 

 of a highly variable Micrococcus which he 

 had isolated many times from milk. Its 

 color ranged all the way from a snow white 

 to a deep orange, and in power of liquefy- 

 ing gelatin it ranged from a form that 

 liquefied with great rapidity to one that 

 had apparently no liquefying power. All 

 these varieties, with numerous interme- 

 diate stages, have been found in nature 

 and are not the result of cultivation. Pro- 

 fessor Conn showed, however, what a great 

 change can apparently be produced in the 

 character of a species, by a simple process 

 of selection. Starting with a pure culture 

 of this organism, he was able to produce 

 from it a white and an orange culture, by 

 simply replating many times, and selecting 

 the whitest color, on the one hand, and the 



