PRIMITIVE INSECTS MYSTIFY

Taranaki Daily News, 31 August 1933, Page 8

PRIMITIVE INSECTS MYSTIFY

SPRINGTAIL AND SILVERFISH. There is an undeniable similarity between spiders and crabs and lobsters and some beetles. Does tills mean that insects evolved from crustaceans and such things as worms and other crawlers? Dr. R. J. Tillyard, of Australia’s Entomological Department, thinks so. He advanced the view that the springtail (it actually leaps with the aid of something very like a spring) and the silverfish (which is not a fish at. all, but which ’ devours carpets) are the most primitive of all insects. Wingless insects, he suggested, came from springtails and silverfish, to be followed by the more highly developed flying types. To prove his case he pointed to winged insects embalmed in coal. They are the oldest of their kind known. Still other fossil insects are found in various older formations. All are wingless. The further down we go in the scale of life the greater is the chemical unity , with its environment. Your real primi- | fives are one-celled animals, and such things as starfish., and shell fisli. On the whole, these creatures are chemically much like the sea water in which they live. But the proportions are different. Here is a mystery for the biochemist to solve. .Why should corals be all cal-,

cium?. Why should molluscs devote themselves to taking up iron, copper and iodine—all very scarce in sea water? Dr. Paul S. Galtsoff (United. States Bureau of Fisheries) did much interesting speculating on these matters. It was ' his guess that the creatures seized what ( their blood, demanded wherever bipod was involved. But blood implies a fairly high form of life. So we are left puzzling about the chemical selectivity of , things that are bloodless—