OF WASHINGTON. 89 



that the ancestral distinction belongs to the so-called neuropterous 

 orders with aquatic larva? and complete metamorphoses. Dys- 

 critina as the larva of an earwig, and Projapyx as the larva of 

 Japyx, bring the orthopterous series closer to the aquatic larvae 

 of the Neuroptera, with their many-jointed stvlets, and thus per 

 mit us to think of the archetypal insect as a creature with meta 

 morphosis and with wings instead of beginning with a thysanuran 

 ancestor and being compelled to imagine the wings as appearing 

 kt independently at several points" as maintained bv Professor 

 Smith.* 



For the correctness of this view, that the neuropterous orders 

 with aquatic larvae are the more primitive,! a large amount of 

 evidence might be brought together, but perhaps the most con 

 spicuous advantage of this standpoint lies in the fact that it per 

 mits the suggestion of an origin and method of development for 

 the insect wing, which can scarcely be accounted for by any 

 rational evolutionary theory beginning with the assumption that 

 the first insects were land animals. 



The wings of the birds, pterodactyls, bats, fishes, and other 

 flying animals, are known to be modifications of organs used for 

 locomotion in water or on land, but we have been contented to 

 assume that the wings of insects were made, so to speak, from 

 whole cloth, and have failed to associate them as the homological 

 equivalents and derivatives of older structures used for purposes 

 other than flight. 



Kinetic evolution views as normal the progressive change of 

 any particular part, but would not prearrange and carry forward 

 the complex and delicate adjustments of structure and function 

 necessary to the perfection of such organs as wings, since, except 

 for flying, wings are about as useless structures for terrestrial in 

 sects as could well be imagined, and some representatives of 

 nearly all the orders have abandoned them. 



But if the discussion be transferred to the water, we have, so 

 to speak, much clearer sailing. Fins too small for flying are still 

 very useful to fish, and a gradual and natural increase of size of 

 swimming organs to the point where they can be used for flight 

 is illustrated by the analogy of the flying fishes.J 



* An Essay on the Classification of Insects, Science, N. S., v, p'. 671, 

 April 30. 1897. 



tThe copulatorj apparatus of the Odonata, located on the second seg 

 ment of the abdomen, is paralleled only in the Diplopoda. The paired 

 genital openings of the Ephemerida and the moulting of the insect in 

 adult form are, if possible, even more primitive features. 



I Some of the so-called flying fish merely soar for short distances on 

 their expanded wings, but others are capable of true flight, not by flapping 

 their wings like birds, but bv keeping them in a state of very rapid vibra 



