ON FLIGHT. 

 By R. von Lendenfeld, Ph.D. 



The locomotion of animals has been the topic of an ever 

 increasing number of papers since Marey published his unparalleled 

 book (1) on this subject. Of all the different modes of locomotion 

 none is so interesting as flight, because the organs adapted for this 

 function are much more highly developed than any other locomotive 

 organs. 



In studying this subject one would naturally assume that the 

 size of the wings was in proportion to the weight of the body, and 

 that an animal would fly the better, the larger the relative size of 

 the wings. It has however, been shown by myself and others, that 

 this is by no means the case, and that an insect the relative size of 

 whose wings is equal to the relative size of the wings of a swallow, 

 cannot fly (grasshoppers, Dytiscus, &c.) 



I have explained this fact by asserting that the very short wings 

 of small animals would reqviire a rapidity of motion, to have the 

 same efi'ect as the long wings of large animals, which is altogether 

 incompatible with the celerity of the muscular contractions, and 

 which has not been observed by Marey, who measured the number 

 of wing-flaps per minute, nor by myself, who measured the extent 

 of the angle which is passed through by the moving wing. I have 

 previously asserted that the resistance of the air to flight was equal 

 to C^ that is the cube of the rapidity. The rapidity in itself is of 

 course a factor depending not only on the rapidity of the wing- 

 flaps and their angles, but also on the length of the wing increasing 

 in pro})ortion to the latter. 



All these statements have been laid down in an essay published 

 some years ago by me (2 .) 



(1) Marey. Locomotion ammale, International Scientific Series. 



(2) V. Lendenfeld. Der Fhig der Libellen Sitzungsberichte der Kais. 

 Academie der Wissenschaften in Wien. Band 81. 



