BIOLOGICAL BULLETIN 



OF THE 



flOarine Biological laboratory 



WOODS HOLE, MASS. 



VOL. LI I MAY, 1927 No. 5 



CONTENTS 



Mi.UMF.NTllAL, RRUHKN. Tin' H/rcl of Cyanides on tin' .S'-iiV/////!; of 



Protoplasm 3 i 3 



I IOLMKS, S. J. The Lou- .SV.v Ratio in Negro Births and 



Its Probable Explanation 325 



WERNER, ORILLA STOTLER. The Chromosomes of the Indian Runner 



Duck 330 



PLOUGH, HAROLD H. Defective Platens Larva from Isolated 



Blastomcres of Arbacia and Echinarach- 

 nius 373 



PLATH, O. E. The Natural Grouping of the Bremidce 



(Bombidce) icilh Special Reference to 

 Biological Characters 394 



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