CAUSE OF DIGITAL REDUCTION. 2G9 



The cause of digital reduction is another interesting inquiry. 

 Bunodonts as a rule are dwellers in swamps and forests and 

 live on nuts, berries, and roots. If they are compelled to for- 

 sake their natural habitat and live in the open field, either 

 modification or extinction will follow. Once in the open field 

 speed becomes a desideratum as a condition of safety, and the 

 foot with a reduced number of digits possesses many advan- 

 tages over the poly dactyl e one. 



Prof. Cope has shown (American Naturalist, April, 1881) 

 that in plantigrade quadrupeds the extremities of the toes are 

 arranged in a semicircle, when they are all applied to the 

 ground. In the act of running the Leel and wrist are raised, 

 throwing the weight of the body on the median digits. An 

 infinite repetition of this posture in digitigrade animals unable 

 to withstand the attacks of their enemies and whose only 

 escape was in flight, the strengthening of the median digits, 

 and the consequent reduction of the outer ones, would follow 

 according to the law of use and disuse of parts. This subtrac- 

 tion of toes has progressed step by step until the modern one- 

 toed horse has been reached. 



In summing up an article in the Kansas City Review of Science 

 and Industry, Mr. Wortman says : 



" I dare say that if all the intervening individuals between 

 Phenacodus and Equus could be produqed classification would 

 be utterly impossible, so insensible would be the gradation." 



The forms already known appear to point to the inevitable 

 conclusion that the modern horse is the product of the slow 

 but improving processes of evolution, which are still in opera- 

 tion, and are being aided by all the skill known to modern 

 science. A discussion of the subject is almost superfluous, for 

 the illustrations, like deeds, speak louder than words. 



Note. Pliny (B.C. 23) says Caesar had a 5-toed horse (the forefeet), which 

 was represented in his (Pliny's) day hy a statue ; also that Epigenes says the 

 Babylonians had a series of observations on the stars for a period of 720,000 

 years, inscribed on baked bricks. Berosus and Critodemus say 490,000. 

 (Vol. ii. pp. 221-317.) Baked bricks have been found buried in the valley 

 of the Nile at a depth to require the annual deposits of that river for 9,000 

 years (72 feet.) May they not some day be valuable aids to science as well 

 as history ? Their stories can be better imagined than described 



