80 CHANGES OP CLIMATE DURING GEOLOGICAL PERIODS. 



action. Near the lake of Thun, one of the granite blocks of this formation is 

 nearly 100ft. square. It is red, and of a kind not now to be met with 

 in situ anywhere in the Alps. Similar erratics of the same age have 

 been found in the Carpathians and in the Apennines. 



In the lower Permian conglomerates of the West of England there are 

 unmistakable signs of ice-action. These contain angular fragments of 

 various rocks, striated or polished, which can often be traced to Welsh 

 rocks, from twenty to thirty miles distant. Evidence of a similar kind — 

 more or less full— has been furnished of glaciation, and of warm periods 

 in each of the other geological epochs. There is, therefore, abundant 

 proof of many distinct alternations in past ages, of arctic and temperate 

 climates. 



How can we account for these alternations ? It seems natural to 

 conclude that the main reason for them must be sought in the changes 

 which have taken place in the relation of the earth to the sun. These 

 changes, however, have been asserted by eminent astronomers to be 

 inadequate to account for these effects. This is quite correct, so far as 

 the direct influence of solar heat is concerned, but the indirect influence 

 of greater or less amount of that heat is much more efficient than the 

 direct. Physical as well as astronomical calculations are needful, in 

 order to estimate the changes which are thus wrought. The direct 

 results of the precession of the equinoxes, and of the eccentricity of the 

 earth's orbit, are greater than have usually been admitted by astronomers. 

 Calculations, extending over long periods, of the variations of eccentricity 

 have been made by Leverrier and others, one of whom, Mr. James 

 Croll, of the Geological Survey of Scotland, has published an elaborate 

 work on the subject of this paper, entitled " Climate and Time, in their 

 Geological Eelations." This book is my authority for many of the 

 following statements. 



(To be continued.) 



THE CEYPTOGAMIC FLORA OF WARWICKSHIRE. 



BY JAMES E. BAGNALL. 



(Continued from page 12.) 

 SECTION n.— AMPHOCAEPI. 



FISSIDENTACE^. 



399. — Fissidens bryoides Hedw. Marly and sandy banks, frequent. Sutton 

 Park ! Knowle ! Acocks Green ! &c. February. 



400. — F. exilis Hedw. On rabbit heaps and clayey soils in woods, and 

 on banks in Lias soils, rather rare. Bearley ! Haywoods ! Canal 

 bank near Acocks Green ! Laue near Tarningale Common ! 



February. 



401. — F. incurvus Schwg. Clayey banks, local. F. viridulus, e. incurvus 

 Wils. Bearley, on banks near the village, Solihull ! Canal 

 bank near Solihull and Olton ! Temple Grafton ! Lane near 

 Yarningalc Common ! March. 



403. — F. tamarindifolius Brid. Marly banks, rare. Near Princethorpe ! 

 Drayton bushes ! near Binton Bridges ! March. 



