CONTENTS 



No. 1. MARCH 



Peter Okkelberg. The early history of the germ cells in the brook lamprey, 

 Entosphenus wilderi (Gage), up to and including the period of sex differen- 

 tiation. Four text figures and twelve plates (seventy-eight figures) 1 



R. Kudo. Studies on Microsporidia, with special reference to those parasitic 

 in mosquitoes. One text figure and five plates (one hundred seventeen 

 figures) 153 



HiRowo Ito. On the metamorphosis of the malpighian tubes of Bombyx 

 mori L. Fifteen figures 195 



R. W. Shufeldt. Observations on the cervical region of the spine in 

 chelonians. Five figures 213 



A. G. PoHLMAN. The position and functional interpretation of the elastic 



ligaments in the middle-ear region of Gallus. Twelve figures 229 



No. 2. JUNE 



James Rollin Slonakek. The development of the eye and its accessory parts 

 in the English sparrow (Passer domesticus). Ten text figures and seven- 

 teen plates (figures 1 to 105) 263 



W. Harold Leigh-Sharpe. The comparative morphology of the secondary 

 sexual characters of Elasmobranch fishes. II. The claspers, clasper 

 siphons, and clasper glands. Fifteen text figures 359 



Harry H. Charlton. The spermatogenesis of Lepisma domestica. Six 

 plates (ninety-five figures) 381 



James Ernest Kindred. The chondrocranium of Syngnathus fuscus. Four- 

 teen figures 425 



E. Eleanor Carothers. Genetical behavior of heteromorphic homologous 



chromosomes of Circotettix (Orthoptera). Five plates (thirty-five figures). 457 



No. 3. SEPTEMBER 



Gencho Fujimura. Cytological studies on the internal secretory functions 

 in the human placenta and decidua. One diagram and two double plates 

 (ninety-six figures) 485 



A. M. Reese. The structure and development of the integumental glands 

 of the Crocodilia. Six plates (forty-six figures) 581 



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