VI 



Marvels of the Universe 



unjustly suspected of secret drinking. It is probable that one or more of his semi-circular canalb 

 was out of order. 



The cochlea contains a wonderful and complicated organ, discovered by Count Corti. This 

 appears to be, in fact, a microscopic musical instrument, composed of some four thousand complex 



arches, increasing regularly in length and 

 diminishing in height from the base to the 

 summit of the cochlea. The waves of sound 

 have been supposed to play on this organ, 

 almost like the fingers of a performer on the 

 keys of a musical instrviment. 



We thus obtain a glimpse, though but a 

 glimpse, of the manner in which the organ of 

 Corti may possibly act, but how these vibra- 

 tions are detached and transmitted to the 

 brain, how they are then transmuted into 

 sounds, we have really no conception. 



Lastly, we come to the eye : a marvellous 

 and most complex organ. Externally is the 

 cornea, then comes the vitreous humor, fol- 

 lowed by the lens, the aqueous humor, and, 

 lastly, the retina. The lens throws an image 

 on the retina, which is very complicated, and 

 though no thicker than a sheet of thin paper, 

 consists of no fewer than nine separate layers, 

 the innermost being the rods and cones, which 

 are the immediate recipients of the undula- 

 tions of light. The number of rods and cones 

 in the human eye is enormous. At a moderate 

 computation the cones may be estimated at 

 over three millions, and the rods at thirty 

 millions. 



It will be observed that the nerve does not, 

 as one might naturally have expected, enter 

 the eye and then spread itself out at the back 

 spider, as seen under a microscope. of (^^e rctlna j but, ou thc coutrarv, pierces 



the retina and spreads itself out on the front, so that the cones and rods look inwards, and not 

 outwards — towards the back of the eve, and not at the object itself. In fact, we do not look out- 

 wards at the actual object, but we see the object as reflected from the base of our own eye. Knowing 

 then, as we do, so little about our own senses, it is natural that those of other animals should be 

 still more of a mystery. Moreover, why should we assume that they have only our five senses ? 



Many years ago I showed that the ultra-violet rays which are in\'isible to us, are on the 

 contrary visible to some of the lower animals. Moreover, looking at the question from the other 

 side, we find in animals complex organs of sense, richly supplied with nerves, but the functions of 

 which we are as yet unable to explain. There may be fifty other senses as different from ours as 

 sound is from sight ; and even within the boundaries of our own senses there may be endless 

 sounds which we cannot hear, and colours of which we have no conception. 



But although what we know is such an infinitesimal fraction of what we have still to learn, on 

 the other hand, the inventions and discoveries of the last century have been really marvellous. To 

 name only a few — railwaj;^ and steamers, telegraphs and photography, gas, petroleum, and electric 



Pholo hy'] 



I he cla^vs of 



[J. E. !<mUli. 



