CONTENTS OF VOLUME XVIII. 



No. 1. December, 1909, 

 Wager, Ralph E. The Oogenesis and. Early Development of Hydra. 1 

 Lombard, Guy D. Some Notes on the Anatomy of the Thyroid Gland 



in Selachii 39 



Pearse, a. S. Autotomy in Holothurians 42 



Holmes, S. J., and Loomis, H. M, The Heredity of Eye Color 



and Hair Color in Man 50 



No. 2. January, 1910. 



Smith, Frank. Hydroids in the Illinois River 67 



Wright, Albert H. The Anura of Ithaca, N. Y.: A Key to Their 



Eggs 69 



Stevens, N. M. A Note on Reduction in the Maturation of Male 



Eggs in Aphis 72 



Morgan, T. H., Payne, F., and Browne, E. N. A Method to 



Test the Hypothesis of Selective Fertilization 76 



Andrews, E. A. The Anatomy of the Stylets of Cambarus and of 



Astacus 79 



No. 3. February, 1910. 



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- Function in 



the Silkworm {Bombyx Mori) 120 



Hatai, Shinkishi. a Mathematical Treatment of Some Biological 



Problems 126 



King, Helen Dean. Temperature as a Factor in the Determination 



of Sex in Amphibians 131 



ToRREY, H. B. Differentiation in Hydroid Colonies. II. Aglao- 



phenia 138 



No. 4. March, 1910. 

 Holmes, S. J., and Homuth, E. S. The Seat of Smell in the Crayfish. 155 

 Child, C. M. Analysis of Form Regulation with the Aid of Ances- 



thetics 161 



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