254 THE POPULAR SCIENCE MONTHLY. 



ing. The eyelids and other parts of the body covered with hair or 

 down may also suffer from the vegetable parasite causing the disease 

 (3Iicrosporon Audouin). In children and adults with thick hair this 

 disease may remain long undetected. Practitioner. 



O 



THE KATE OF ANIMAL DEVELOPMENT. 



By J. "W. SLATEK. 



"Consider young ducks." 



NE of the attempts which have been made to establish the ex- 

 istence of a " great gulf " between man and beast may be pro- 

 nounced exceptionally curious as an instance alike of careless and 

 defective observation and of rash conclusions. That by such argu- 

 ments men of eminence could really mislead themselves, and succeed 

 for a length of time in misleading the outside public, is deeply humili- 

 ating. Professor St. George Mivart suggests* that a book should be 

 written on the " stupidity of animals." We are far from denying that 

 such a work would be useful ; but, should the needful companion vol- 

 ume on the " stupidity of man " make its appearance in due course, it 

 might not unfittingly open with the reasoning we are about to quote. 



To begin, then : the slow bodily development of the human infant 

 and its prolonged helplessness are matters far too familiar to require 

 proof, or even illustration. No less familiar and universally admitted 

 is the rapidity with which foals, calves, lambs, kids, chickens, and 

 ducklings acquire the use of their limbs and other organs. These facts 

 could not fail to come under the notice even of the most careless ob- 

 servers. But, who could have imagined that the said facts would be, 

 without further inquiry, at once seized hold of as a theme for stilted 

 declamation, and be elevated to the rank of a fundamental distinction 

 between man and the lower animals ? Yet this strange error has actu- 

 ally been committed, not merely by men of words, like Addison, Paley, 

 and Whewell which is surely sad enough but even by a man of 

 things, like Sir Humphry Davy. The great chemist attempts to show 

 that man does not use his limbs instinctively, like other animals. Says 



he : 



" Man is so constituted that his muscles acquire their power by 

 habit,f but in the colt and the chicken the limbs are formed with the 

 power of motion, and these animals walk as soon as they have quitted 

 the womb or the egg. 



* "Lessons from Nature." 



f To speak of acquiring a power by habit is scarcely rational. The power must exist 

 before the habit can be formed. 



