BIOLOGICAL BULLETIN 



fiDarine :©tolootcal OLaborator)? 



WOODS HOLE, MASS. 



Vol. XVIII February, 19 id No. 3 



CONTENTS 



Page 



Heath, Harold. A New Genus of Parasitic Gastropods 99 

 Child, C. M. The Occurrence of Amitosis in Moniezia 109 

 McCracken, Isabel. The Manifestation of the Flight-Func- 

 tion in Silkworm (Bombyx Mori) 120 



Hatai, Shinkishi. a Mathematical Treatment of Soyne Bio- 

 logical Problems 1 36 



King, Helen Dean. Temperature as a Factor in the Deter- 

 mination of Sex in Amphibians 131 



ToRREY, H. B. - Differentiation in Uydroid Colonies. II, 



Aglaophenia 138 



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■ii 141 



4. 



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