The wingless forms in question are always allied to winged forms, and there is every reason to believe that they have been really derived from winged forms. There are also insects (fleas, &c.) in which metamorphosis of a complete character exists, though the insects never develop wings.
fleas הגייה עם משמעויות, מילים נרדפות, הפכים, תרגומים, משפטים ועוד