POLAR ORIGIN OF LIFE 
23 
Strait alone. Mr. Emerton * * * § makes mention of several 
instances among spiders. 
Such cases can be traced among earth-worms, beetles, wood- 
lice, ants and other groups. In some cases the identity or 
similarity of species occurring on the two continents may be 
due to the fact that the species originated in Greenland or 
some polar centre, no longer in existence, and subsequently- 
travelled in different directions towards their present habitat. 
This conception, however, has very little in common with that 
of a polar origin of life which was first mooted by Dr. Allen.f 
He argued that the northern circumpolar lands may be looked 
upon as the base or centre from which have spread all the 
more recently developed forms of mammalian life. 
A few r years later Dr. Haacke J directed attention to the 
peculiar circumstance that the most primitive orders of 
mammals and birds all have their living representatives 
in outlying areas of the southern hemisphere, such as 
Australia, New Zealand, Madagascar, South Africa and 
South America, notwithstanding that these animals are 
known to have formerly inhabited the northern hemis¬ 
phere. This, he thinks, implies that a southward re¬ 
treat has taken place of the more ancient forms before 
the advancing host of higher orders of life. It would 
seem, therefore, as if streams of more and more highly 
specialized orders of mammals and birds had been slowly 
evolved in the north and had constantly pressed the older ones 
southward. This suggested to Dr. Haacke the idea of a polar 
continent from which the various orders had gradually been 
distributed across the continents. Dr. Wilser § even assumes 
a polar origin for man. 
A similar theory was pronounced by Canon Tristram Ij in 
explanation of the present distribution of the higher groups of 
birds and their migrations. The migratory instinct, he con¬ 
tended, was due to their having originated in a polar centre 
* Emerton, J. H., “Spiders common to New England and Europe,” 
•p. 129. 
t Allen, J. A., “Geographical Distribution of Mammals,” p. 375. 
j Haacke, W., “ Nordpol als Schopfungszentrum.” 
§ Wilser, L., “ Der Nordische Schopfungsherd,” p. 134. 
|| Tristram, H. B., “ Polar Origin of Life.” 
