WITH THE DOMAIN OF THE INORGANIC 53 



§ 4. Abundance and Insurgence of Life. 



'A second impression is that of wealth of numbers and of 

 indomitable will to live. There are, indeed, organisms which 

 multiply slowly, such as elephants, golden eagles, and cen- 

 tury plants, but this is not the way with the majority. JMost 

 of the streams of life are ever tending to overflow their 

 banks. Even the rarities may do so in appropriate condi- 

 tions ; thus a rather rare wingless Glacier-Insect was recently 

 found on one stretch of the mer-de-glace at Chamonix in 

 numbers almost equal to the population of Great Britain and 

 Ireland. In the case of organisms of low individuation, 

 which hold their own rather because they are many than be- 

 cause they are strong or wise, the productivity is beyond all 

 our powers of conception. From one Infusorian there may be 

 a million by the end of a week, and in some of the floating 

 meadows of the sea there may be a quarter of a million units 

 in a gallon of water. 



There is a well-known British starfish, Luidia cilians, 

 which produces at least two hundred millions of eggs, and yet 

 it is not what one would call a common animal. 



We are familiar with calculations of what would occur 

 if there were no thinning of the crops — how soon the earth 

 would be covered with a weed, or the sea filled solid with a 

 fish, or the sky darkened with an insect, and recurrent 

 plagues of locusts, sparrows, rabbits, and moles remind us 

 that a possibility may easily become an actuality. After 

 allowing a prodigious mortality of 95 per cent., it is com- 

 puted that the 10,000,000 pairs of breeding rats in Britain 

 on New Year's Day, 1918, were represented by 40,000,000 

 pairs at the end of the year, and by 12,000,000 more pairs 

 the following month ! There is a grimness in the well-known 



