VOL. XXXIX, No. 464 AUGUST, 1905 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 



DEVOTED TO THE NATURAL SCIENCES 

 IN THEIR WIDEST SENSE 



CONTENTS 



Page 



I. A Systematic Study of the Salicaceae . PROFESSOR D. P. PENHALLOW 509 



II. Developmental Stages in the Lagenidse . . . . J. A, CUSHMAN 537 



III. Studies on the Plant Cell. VII DE. B. M. DAVIS 555 



IV. Notes and Literature: Nature Study ; Zoology, Wasps Social and Soli- 



tary, Trouessart's Catalogus Mammalium, Supplement 601 



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