We may believe that the progenitor of the ostrich genus had habits like those of the bustard, and that, as the size and weight of its body were increased during successive generations, its legs were used more and its wings less, until they became incapable of flight.

Kirby has remarked (and I have observed the same fact) that the anterior tarsi, or feet, of many male dung-feeding beetles are often broken off; he examined seventeen specimens in his own collection, and not one had even a relic left.

In the Onites apelles the tarsi are so habitually lost that the insect has been described as not having them.

In some other genera they are present, but in a rudimentary condition.

In the Ateuchus or sacred beetle of the Egyptians, they are totally deficient.