12 THE POPULAR SCIENCE MONTHLY. 



which would foil the eye ; but it would be also impossible, because the 

 complications of movement would confuse it. But, where the optical 

 sense fails, the auditory sense succeeds. The membrane of the ear re- 

 ceives the torrent of motion, and transmits it with all its harmonies. 

 In an orchestra, where scores of instruments are playing through the 

 whole compass of the scale, the air is cut into waves by every com- 

 plexity of vibration grave tones mingle with shrill, soft with harsh, 

 fundamentals are merged in overtones, and the storm of impulses is 

 shot with the speed of rifle-bullets against the tympanum ; and yet 

 there is no confusion. In all their infinite diversity of qualities the 

 waves are legible to the little membrane. It vibrates to the lowest 

 and to the highest, to each and all, and telegraphs the whole per- 

 formance with incomprehensible exactness to its cerebral destination 

 and an exquisite work of art is produced in the sphere of pleasurable 

 feeling and critical intelligence. 



Our glance at this fascinating subject has been very imperfect, but, 

 if any care to pursue it, we recommend them to the admirable book 

 of Prof. Tyndall, " On Sound," to which we are indebted for the fore- 

 going illustrations, and for many of the facts stated. 







INSTINCT IN INSECTS. 



By GEORGE POUCHET. 



TRANSLATED FROM THE FRENCH, BY A. R. MACDONOUGH, ESQ. 



I. 



WHAT is instinct ? In what does it differ from intelligence ? 

 What explanation can be given of it in the present state of 

 the sciences of life ? All these are questions to which a positive an- 

 swer is asked for the first time in our day. Philosophers and moralists 

 do not in our time concern themselves with the relations or the differ- 

 ences between instinct and intelligence; for they have no means of 

 solving problems that particularly concern biology. Without going 

 farther back, we remember Descartes's strange notion of animal ma- 

 chines, adopted by Bossuet, and the whole seventeenth century ; but 

 at this time biologists in their turn attack the problem ; anatomy and 

 physiology will perhaps give us the solution sought in vain at the 

 hands of philosophic and religious systems since the days of Aristotle 

 and St. Thomas. 



George Cuvier was the first to draw a clear distinction between 

 instinct and intelligence, in the second edition of the "Animal 

 Kingdom" (1829), in which he digests the works published during the 

 course of several years, by his brother Fredei'ic. The latter, placed 

 in control of the menagerie of the museum, believed that it pertained 



