AUTHORITIES 145 



general among the lower marine organisms is not generally 

 accepted by English zoologists. It has been developed by Putter 

 in Ernahrung der Wassertiere (Fischer, Jena, 1909). There 

 is an account of Putter's earlier work in Science Progress for 

 July, 1908, with references to the literature. 



7. Plant-Animals. 



See Keeble's book in this series. There is a bibliography, and 

 the general question of nitrogen hunger is discussed. 



8. Denitrification in the sea. 



The suggestion that this occurs was first made by Brandt, see the 

 Wisseuschaftliche Meeresuntersuchungen, Vol. 4, 1899, and Vol. 6, 

 1902 'StoflFwechsel im Meeres.' These papers are very important 

 but they have not been translated. They are reviewed and 

 full references are given in Science Progress, Oct. 1907. The 

 hypothesis that the distribution of plant-life in the sea is 

 conditioned by denitrification is probable, but investigation of 

 the occurrence of these bacteria in all seas is still wanting. 



9. Temperature and the duration of life. 



The hypothesis which is mentioned in this book is due to Loeb. 

 See Archiv fur die Gesammten Physiologie, Bonn, Bd. 124, 1908. 

 The hypothesis, which is nevertheless a very probable one, is 

 supported by some very inadequate experiments : these must 

 be extended and confirmed before the 'coefficients' can be 

 accepted. 



10. The theory of tropisms. 



This is the subject of a very large literature, but see Loeb, 

 Dynamics of Living Matter, Columbia University Biological 

 Series, 1906. 



11. Jennings' book, Behaviour of the Lower Organisms, Columbia 

 University Biological Series, 1906, describes numerous experimental 

 results. It and Driesch's Science and Philosophy of the Organism 

 (A. and C. Black, 1907-8) should be read. They take a view of 

 animal behaviour directly opposed to that of the tropistic theory. 



J. 10 



