FLYING REPTILES 79 



An occasional bold spirit, undeterred by the assertion 

 that feathejrs could not have been evolved twice, has 

 ventured to suggest that the ostrich never did fly and 

 that he is descended from quite a different ancestor 

 than that from which flying birds are derived. If 

 nature can put a back fin on a reptile as well as on a 

 porpoise and if it apparently serves no useful purpose in 

 either case, why could she not have developed feathers 

 twice in the course of many million years? It may not be 

 probable but it $3 surely possible and I for one see no 

 impossibility in ostriches having descended from one 

 group of reptiles and the fan-tailed birds, through 

 ArchaBopteryx, from another. 



REFERENCES 



The American Museum of Natural History and Yale 

 University Museum each have a fine, mounted skeleton of 

 Pteranodon and Yale University has one of the very few speci- 

 mens of pterodactyls showing the imprint of the wing membrane. 



By far the best account of Pterodactyls in general is to be 

 found in Seeley's "Dragons of the Air" in which they are dis- 

 cussed from all points of view. " The Greatest Flying Creature " 

 (Report of the Smithsonian Institution for 1901} gives much in- 

 formation in regard to wing area and other problems of flight. 



In the u Mronautical Journal" for October, 1914, pages 324- 

 343, will be found articles by H. B. Hawkins, D. M. S'. 

 Watson and G. Howard Short, On the Flight of Pterodactyls 

 and the Wing Adjustments of Pterodactyls in which these sub- 

 jects are considered at length. 



