PROBLEMS OF DISTRIBUTION AND THEIR SOLUTION. 143 



is similarly explicable on the ground that the distribution of life 

 shows us the natural divisions and natural geography of the globe. 

 It now remains to investigate the limits and boundaries of these 

 divisions (or " zoological regions," as they are named), to indicate 

 the more familiar types of life resident in each, and to ascertain, last 

 of all, the chief facts which, when brought into scientific relationship, 

 serve to explain how and why the life of the earth has been thus 

 distributed. 



Mr. Sclater, the secretary of the Zoological Society of London, 

 proposed, from a consideration of the bird-life of the globe, to divide 

 the earth's surface into six provinces or regions. These regions, 

 whilst indicating the distribution of the birds, likewise serve to show 

 that of the quadrupeds ; whilst it is found that they also represent 

 the essential features of the distribution of still lower grades of life. 

 Mr. Sclater's six divisions have received, with one or two modifica- 

 tions, the common approval of naturalists. Professor Huxley, it is 

 true, has proposed a somewhat different division of the earth's 

 surface, and it may be convenient in the first place to note this 

 latter arrangement. Making four provinces from the consideration 

 of the distribution of fauna, Huxley divides the earth's surface as 

 follows : 



Zoological Province Geographical Equivalents 



I. Ornithogosa or Nova-Zelanian . . New Zealand alone. 



II. Antarctogcea or Australian . . | Australia, Tasmania, and Negrito 



Islands. 



III. Dendrogsea or Austro-Columbian . J South Africa, Central America, 



\ and Mexico. 



f(i) North America (N. of Mexico). 



(2) Africa (S. of Sahara). 



(3) Hindostan. 



i (4) Europe, Asia (except India), 

 V and Africa (N. of Desert). 



The effect of this arrangement is to bring prominently into view 

 the biological peculiarities of New Zealand, Australia, and South 

 America, and to relate more nearly together those quarters of 

 the globe (Europe, Asia, India, and Africa) which possess more 

 features in common than the other and more specialised provinces. 

 With all deference to such high authority as Professor Huxley in 

 himself represents, one objection to his system of zoological geo- 

 graphy may be found in the fact that the claims of New Zealand to 

 rank as a distinct zoological region are highly debatable. Again, in 

 the system propounded by Mr. Sclater, the geographical equivalents 

 of Huxley's Arctogcea are practically retained, and the not incon- 

 siderable merit of simplicity, as well as considerations relating to the 

 distinctness of the fauna, may weigh in the minds of naturalists as 

 favouring the adoption of Mr. Sclater's provinces of distribution. 



