Contents. v 



PAGE. 



VI. The Origin of the Electric Organs in Astroscopus guttatus. By E. Grace White. 



7 plates, 1 tcxt-figui-e 139-172 



Historical Survey of the Subject 142 



Observations 150 



Experimental 162 



Discussion 163 



Summary 166 



Bibliography 168 



Explanation of Plates 171 



VII. Toxic Effects due to High Temperature. By Alfred Goldsborough Mayer. . 173-178 



Summary 178 



Literature Cited 178 



VIII. Nerve-Conduction in Diluted and in Concentrated Sea-Water. By Alfred 



Goldsborough Mayer. 1 text-figiu-e 179-183 



IX. A Study of Respiration in Alcyonaria. By Lewis 11. Gary 185-191 



Experimental 187 



Discussion 189 



Relation between Death Temperatui'e and Rate of Metabolism 190 



Literature Cited 191 



X. Migration of Insects to Rebecca Shoal Light-station and the Tortugas Islands, with 



special reference to Mosquitoes and Flies. By S. C. Ball 193-212 



Means by which Insects may reach Rebecca Shoal Light-house 196 



Opportunities for Breeding of Mosquitoes at Rebecca Shoal 198 



Conditions at Rebecca Shoal Light-station just prior to June 26 199 



Methods of obtaining Insects which visited the station 200 



Insects taken at Rebecca Shoal between June 26 and July 18, 1917 201 



Migration of the House-fly 207 



Occurrence of other Diptera at Rebecca Shoal 210 



Other Insects noted at Rebecca Shoal 210 



Evidence that Odonata and Leptidoptera Migrate to Tortugas 210 



Do Sarcopliagidse breed at Tortugas? 211 



Summary 212 



BibUography 212 



XI. 071 Changes in the Sea and their Relation to Organisms. By J. F. McClendon. 



8 figures 213-259 



Methods 218 



Cui-rents 221 



Records of all Stations and of a Tank of Sea-water 222 



Relation of Oxygen Tension and Activity of the Nervous System to Metabolism 



in Cassiopea 235 



On the Chemical Precipitation of CaCOa in Sea-water 252 



Bibliography 259 



