

PREFACE. 



Veey few words are required to introduce to our 

 readers the Third Volume of the Sixth Series of this 

 Journal. 



The number of its pages will at once show that 

 there has been no lack of contributions during the 

 past year ; indeed we owe apologies to several 

 valued correspondents for being obliged to hold over 

 their communications until our next issue. 



We wish to invite special notice to two articles in 

 the present volume which refer to branches of our 

 Science that have not yet received the attention they 

 seem to deserve. These are Mr. Lydekker's memoir 

 on fossil birds, and Mr. William Evans' account of the 

 periods of incubation in various groups. Both these 

 subjects are, in our opinion, well worthy of further 

 study. 



P. L. S. 



3 Hanover Square, London, W. 

 Sept. 1st, 1891. 



