IV CONTENTS OF VOLUME XY. 



Pearl, Maud DeW. , and Pearl, Raymond. On the Relation of 



Race Crossing to the Sex Ratio 194 ^^ 



No. 5. October, 1908 

 Newman, H. H. A Significant Case 0/ Hermaphroditism in Fish. 207 "^ 



Turner, C. H. TJie Homing of the Mud-dauber 215 



Chidester, Floyd E. Extrusion of the Winter Egg Capsule in 



Planaria simplississima 226 



Williston, S. W. Lysorophus, a Permian Urodele 229 



Whitney, D. D. Further Studies on the Elimination of the Green 



Bodies from the En do derm Cells of Hydra viridis 241 



No. 6. November, 1908 



Turner, C. H. The Homing of the Burrowing Bees (^Antho- 



phoridce') 247 



Pearse, a. S. Observations on the Behavior of the Holothurian, 



Thy one briarcus (^Leseur') 259 



Breed, Robert S., and Ball, Elsie F. The Interlocking 

 Alechanisms which are Found in Connection with the Elytra 

 of Coleoptera 289 



