temperature
--Further criticism of Mr. Lowell's article
--Very low temperature of arctic regions on Mars.


CHAPTER VII.

A SUGGESTION AS TO THE 'CANALS' OF MARS,
--Special features of the canals
--Mr. Pickering's suggested explanation
--The meteoritic hypotheses of origin of planets
--Probable mode of origin of Mars
--Structural straight lines on the earth
--Probable origin of the surface-features of Mars
--Symmetry of basaltic columns
--How this applies to Mars
--Suggested explanation of the oases
--Probable function of the great fissures
--Suggested origin of blue patches adjacent to snow-caps
--The double canals
--Concluding remarks on the canals.


CHAPTER VIII.

PAGE SUMMARY AND CONCLUSION,
--The canals the origin of Mr. Lowell's theory
--Best explained as natural features
--Evaporation difficulty not met by Mr. Lowell
--How did Martians live without the canals