THE MASTERY OF THE AIR 265 



bright twilight I saw one of these animals run 

 up a trunk in a rather open place, and then 

 glide obliquely through the air to another tree 

 on which it alighted near its base, and immedi- 

 ately began to ascend. I paced the distance 

 from one tree to the other, and found it to be 

 not less than seventy yards, and the amount of 

 descent I estimated at not more than thirty or 

 forty feet, or one in five. This, I think, proves 

 that the Colugo must have some power of 

 guiding itself through the air, for otherwise 

 in so long a distance it would have little 

 chance of alighting exactly on the trunk." 



An interesting point in regard to these 

 parachuting mammals is that there are so 

 many which seem to be independent of one 

 another. It is worth while making a technical 

 list, because it shows how the same impulse 

 must have become urgent over and over again. 



^ ( Perhaps to be ranked 



GALEOPITHECUS . .j amo P ng the Insectivores. 



ANOMALURUS . f Amon f the ro . der f' , re ' 



PETAURISTA . . . J * a * ed . to ^els but 

 SCIUROPTERUS . .] d^ering markedly from 

 (^ one another. 



PETAURUS . . . . ( All of them Marsupials, 

 PETAUROIDES . . . . -j but not nearly related 

 AEROBATES . f to one another. 



