96 MY LIFE [Chap. 



animals from all parts of the world, and it is of special 

 interest to him to be able to see at a glance how each family 

 and genus is distributed, with the number of known species. 

 He thus see what are the deficiencies in his collection, and 

 from what countries he most needs additional species ; and all 

 this information I wished to give him, as I had often felt 

 the want of it myself. This part of the work I termed 

 " geographical zoology," and to this I gave special attention, 

 and have given for every family of mammals, birds, and reptiles 

 a diagram, which in a single line exhibits its distribution in 

 each of the four subregions of the six regions. To give the 

 reader some idea of this compact method of summarizing 

 information, I will give here its application to one family of 

 mammalia : — 



Family 50— Cervid^ (8 genera 52 species). 



Neotropical 

 Subregions. 



Nearctic 

 Subregions. 



Palsearctic 

 Subregions. 



Ethiopian 

 Subregions. 



Oriental 

 Subregions. 



Australian 

 Subregions. 



1, 2, 3, - 



1, 2, 3, 4, 



1, 2, 3, 4, 





1, 2, 3, 4, 



1, 



Here the distribution of the true deer over the earth is 

 shown at a glance when once the limits of the regions and 

 subregions are learnt, as marked on the general and special 

 maps by which the book is illustrated. The work was 

 published in 1876, in two thick volumes, and it had occupied 

 a good deal of my time during the four years I lived at Grays. 

 As this book, being very costly and technical, is less known 

 to English readers than any of my other works, I will here 

 give the titles of the chapters, which will sufficiently indicate 

 the range of subjects treated in its eleven hundred pages : — 



Part I. — The Principles and General Phenomena of 

 Distribution. 



Chap. I. Introductory. 

 „ II. The means of Dispersal and the Migrations of Animals. 

 „ III. Distribution as affected by the Conditions and Changes of the 

 Earth's Surface. 

 IV. The Zoological Regions. 

 „ V. Classification as affecting the Study of Geographical Dis- 

 tribution. 



