24 ANNUAL. EEPORT SMITHSONIAN INSTITUTION, 1910. 



of what is known as Langley's Law as to relation of speed to power 

 in aerial motion, as follows : 



These new experiments (and theory also when viewed in their light) show that 

 if in such aerial motion, there be given a plane of fixed size and weight, inclined 

 at such an angle, and moved forward at such a speed, that it shall be sustained 

 in horizontal flight, then the more rapid the motion is, the less will be the power 

 required to support and advance it. 



COMMISSION ON ZOOLOGICAL NOMENCLATURE. 



An International Commission on Zoological Nomenclature, con- 

 sisting of five members, was appointed in 1895 by the Third Interna- 

 tional Zoological Congress, held at Leyden, Holland, for the purpose 

 of studying the various codes of nomenclature and to report upon the 

 same at a later congress. At the congress at Cambridge, England, 

 in 1898, the commission was made permanent and increased to fif- 

 teen members. At the Berne Congress, in 1904, the commissioners 

 were divided into three classes of five, each class to serve for nine 

 years. 



Committees on nomenclature, to cooperate with the International 

 Commission, have been organized in the United States by the Ento- 

 mological Society of America, the Association of Economic Ento- 

 mologists, the American Ornithologists' Union, and the Society of 

 American Zoologists. 



A code of nomenclature was adoj^ted at the Berlin congress in 1901 

 and was amended at the Boston congress in 1907. Prior to the Boston 

 congress a desire had developed among zoologists that the commission 

 should serve as a court of interpretation of the code, and in accord- 

 ance therewith the commission presented to the Boston congress five 

 opinions, which were ratified by the congress. 



Since the Boston meeting a number of questions on nomenclature 

 have been submitted to the commission for opinion. Owing to the 

 amount of time consumed in communicating with the fifteen commis- 

 sioners it was impossible to act promptly upon these cases, but in 

 December, 1909, the Smithsonian Institution gave a grant to provide 

 for the clerical work for a period of three years, and since that time 

 it has been possible to render the opinions more promptly. 



The commission has no legislative power. Its powers are restricted 

 to studying questions of nomenclature, to reporting upon such ques- 

 tions to the international congress, and to rendering opinions upon 

 cases submitted to it. 



The Smithsonian Institution has also undertaken the publication of 

 the opinions of the commission for a limited period and their distribu- 

 tion to important libraries and to zoological specialists throughout 

 the world. The first issue of these opinions was in press at the close 

 of the fiscal year and included opinions 1 to 25, covering several 



