Papers on Zoology, Entomology and Medicine. 



Observations on Seasonal Distribution and Longevity 

 of Some Acanthocephala from Fresh Water Hosts, 

 Abstract, H. J. Van Cleave 223 



Resistance and Reactions of Fishes to Poisonous Pol- 

 luting Substances from the Manufacture of Illum- 

 inating Gas, Abstract, V. E. Shelford 224 



Variation Induced in Brachiopods by Environmental 

 Conditions, Abstract, Henry M. Dubois 225 



Transformations of Trichoptera, Edna Mosher 226 



Function of the Epipharynx and Hypopharynx in the 

 Diptera, Abstract, Alvah Peterson 229 



Economic Importance of Diptera, J. R. Malloch 230 



The Egg Laying Habits of a Parasitic Dipteron, Pter- 

 odontia, J. L. King 233 



Variation in the Gills of Zygoptera, Philip GarmarL...235 



The Principles of Subcutaneous Medication by Means 

 of Bacteria and Bacterial Products, Michael I. 

 Reiffel 236 



The Cause of Gastric Ulcer, W. E. and E. L. Burge, 247 



Constitution and By-laws 253 



List of Members ...257 



