157 



Mr. Croll, who attributes the changes of climate marking the different 

 periods of the tertiary epoch to periodical variations in the eccentricity of 

 the earth's elliptical orbit, tells us that for the last 60,000 years eccentricity 

 has been very small. High eccentricity would lead to rapid change of species, 

 low eccentricity to a persistence of the same forms ; and as we have been 60,000 

 years, according to this reckoning, in a period of low eccentricity, the rate of 

 change of species during that time may be no measure of the rate in past geo- 

 logic ages. 



"Whatever, or however, these changes have been, there has been a succes- 

 sion of species in time, which has been exactly paralleled by their repre- 

 sentatives over wide areas in space. Each life- germ has been a law to itself, 

 taken ab initio a certain course, unfolding an end and aim, " each perfect 

 after its kind," but assisted by secondary causes, which in past ages and in the 

 Longmynd flora have been conspicuous by their co-operation. 



APPENDIX. 

 Memorandum of rain-fall at "Woolstaston. by the Kev. E. Donald Carr, 



M.A. (above sea-level about 750 feet) : 



1865 

 1866 

 1867 

 1868 

 1869 



Average in 5 years 



Total Depth. 

 31.44 

 35.74 

 32.80 

 33.40 

 33.26 



5)168.64 



33.728 



Number of days 

 on which .01 fell. 



185 



236 



198 



190 



187 



Average depth of rain in 1869 for the whole Kingdom, 34.96 inches ; the 

 average depth of the five years, 1860-65, having been 35.21, as computed by G. 

 F. Symons in "The British Rainfall of 1869." 



