Vol. LXXII. No. 4. APRIL, 1908 



THE 



POPULAR SCIENCE 

 MONTHLY. 



EDITED BY J. McKEEN CATTELL 

 CONTENTS 



Our Inland Waterways. Dr. W J McGeb 289 



Accidental Kesemblances among Animals — A Chapter in Unnatural His- 

 tory. Professor Bashford Dean 304 



The History of Science — An Interpretation. Professor C. R. Mann . 313 



Physics. Professor Ernest Fox Nichols 323 



The Respiration of an Inland Lake. Professor E. A. Birge ... . 337 



The Utilization of Auxiliary Entomophagous Insects in the Struggle 

 against Insects Injurious to Agriculture. Professor Paul Marchal . 352 



The Children's Museum as an Educator. Anna Billings Gallup . . 371 



The Progress of Science : 



The Carnegie Institution of Washington ; Sir Kichard Strachey, The Popularization 



of Science ; Scientific Items 380 



THE SCIENCE PRESS 



LANCASTER, PA. GARRISON, N. Y. 



NEW YORK: Sub-Station 84 

 Single Numbeb, 30 Cents Yearly Subscription, $3.00 



copyeight, 190:;, bt the science press 



