Show tho the Wo alers of ite reproduction production aphides are arc a species of minute insect belonging 6 to the order of suborder and taken collectively of them would hardly weigh a grain now let us try a comparison the average man we will say weighs about grains yet it has been found by actual calculation that if these minute insects were left unchecked to only the tenth generation era tion the descendants of a single pair would ifould be equivalent in point of actual Nv weight eight to very heavy men this would be equal to one third of the population of the globe supposing each cach person to weigh an average of pounds |