ILLUSTRATED BY COLOR PHOTOGRAPHY.
By W. E. Watt.
THE air is an elastic fluid surroundingthe earth. Themotions of things whetheralive or not, set it in a stateof vibration that rarely ceases. At alltimes and in all places it is pulsingresponsively to all that is going on.
Animals are interested in what ismoving about them. It may meanlife or death, pleasure or agony, andmost animals are keen to know whichis for them at any given period. Theyare theref