BIOLOGICAL BULLETIN 



OF THE 



fiDarinc Biological Xaborator^^ 



WOODS HOLE, MASS. 



Vol. XVIII 



December, 1909 



No. I 



CONTENTS 



Page 



Wager, Ralph E. The Oogenesis and Early Development 



of Hydra i 



Lo.MBARD, Guy D. Some Notes on the Anatomy of the Thyroid 



Gland in Selachii 39 



Pearse, a. S. Aictotomy in Holothnrians 42 



Holmes, S. J., and The Heredity of Eye Color and Hair 



LooMis, H. M. Color in Man qo 



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