IN THE MUD OF THE LEVANT. 119 



species of Arica and Callao, the harbour of Lima, 

 that is from 12° to 15° S. lat., in order to compare 

 them with those of 34° S., we have fourteen, of 

 which four extend northwards as far as Paita and 

 to the equator."* The same writer also tells us, 

 that seven species of the Foraminifera, found at 

 the Canaries, are also common to the southern 

 and western coasts of France. One of them, the 

 Truncatulina lobata, also occurs in the British 

 seas and at the North Pole. 



If, then, there is amongst these little creatures 

 such an independence of climate and other outward 

 conditions, the same thing would naturally influ- 

 ence their geological relations. They would 

 survive catastrophes which were fatal to the 

 higher organisms, and thus we might expect, a 

 priori, to find individual species ranging through 

 a number of strata, and during a comparatively 

 long geological period, without affecting the 

 great fundamental views which geologists hold as 

 to the geological distribution and the periodic 

 destruction of most living existences. Such 

 is precisely what we have the authority of 

 M. Ehrenberg himself for beheving to occur ; — 



* Idem, p. 11. 



