CONTENTS 

 Original Papers 



Page 



Optics. — Trigonometric computation formulae for meridian rays. P. V. WELLS. i8i 



Radiation. — Note on the coefficient of total radiation of a uniformly heated 



enclosure. W. W. CoblEntz 185 



Biology. — What kind of characters distinguish a species from its subdivisions? 



William C. Kendall 187 



Evolution. — Evolution through normal diversity. O. F. Cook 192 



Abstracts 



Phytopathology 1 98 



Genetics 1 99 



Zoology 200 



Mammalogy 201 



Entomology 201 



Ornithology .' 201 



Technology 203 



Proceedings 



Washington Academy of Sciences 204 



Botanical Society .* 204 



Biological Society 203 



Entomological Society ; 206 



Scientific Notes and News 207 



