224 NATURAL SCIENCE. Sept.. 



various factors that determine the distribution of animals over the 

 sea-bottom within one zoological area. It is proved to be more im- 

 portant than mere depth ; while the same locality may vary so much 

 from time to time in the temperature, the salinity and the transparency 

 of the water, that these factors, within certain limits, have far less 

 influence upon the fauna than has the nature of the deposit. In the 

 discussion that took place on this paper, Mr. F. A. Bather pointed 

 out how important the study of these modern conditions was to the 

 geologist who attempted to correlate strata by means of their fossil 

 contents ; and he suggested the possibility that at some future epoch, 

 when the floor of the Irish Sea had become dry land, these absolutely 

 contemporary deposits might come to be regarded as a series of 

 successive formations, each characterised by its peculiar " zonal " 

 fossils. A similar state of affairs in the Silurian rocks of Gotland 

 has actually given rise to much heated controversy. 



Among the more interesting discussions in the Geological Section 

 was that which arose out of Dr. Hicks' paper on The Homes and 

 Migrations of the Earliest known Forms of Animal Life as indicated 

 by Recent Researches. Few of the speakers, however, seemed to 

 confine themselves to the real questions at issue, a fact which may 

 have been due to a want of clear understanding of Dr. Hicks' 

 position. We hope that our readers will be able soon to form their 

 own opinions on the subject, as this interesting communication will 

 appear in a future number of Natural Science. 



In the Zoological Sub-section Dr. Otto Maas, whose paper on 

 " Some Problems of the Distribution of Marine Animals " (Natural 

 Science, vol. ii., p. 92) our readers will remember, gave an interest- 

 ing account of " temperature as a factor in the distribution of marine 

 animals." It was pointed out by Messrs. H. N. Dickson and W. 

 Garstang, during the discussion, that much variation of fauna, 

 apparently due to variation of temperature, might really be due to an 

 influx of water from other sources and to the consequent introduction 

 of foreign forms of life, or the change of the chemical and physical 

 characters of the water. Most speakers, however, seemed to think 

 that so important a paper should be published before it could be 

 discussed. We have much pleasure in announcing that the complete 

 work will appear in an early number of Natural Science. 



These seasonal movements of the water in the North Sea and in 

 the Atlantic, which have so much bearing on this subject, were 

 discussed more fully by Mr. Dickson before the Geographical Section. 

 Here also there was a discussion on the distribution of African fish, 

 and, finally, it was here that Dr. John Murray thought fit to read his 

 important paper on the Geographical and Bathymetrical Distribution 

 of Marine Organisms. In the course of this he attempted to 

 demoHsh the Antarctic Continent of Mr. H. O. Forbes, a question on 

 which geologists and zoologists, no less than geographers, might well 

 have been asked for their opinion. 



