36 LEISURE-TIME STUDIES. 



hidden and stored up within the tissues and cells of vegetable 

 life ; and has ferreted out for us many a valuable aid to the 

 art of the physician in the alleviation and cure of disease. 

 But the case of zoology presents even stronger aspects than 

 that of botany. For I have but to remind you of the multi- 

 farious objects of commercial gain and speculation which are 

 derived from the animal world, to show you how zoology 

 relates herself to trade. Our furs and fisheries, our pearls 

 and shells, our fats and oils, our daily food, and our many 

 luxuries, come wholly, or in greater part, from the zoologist's 

 domain. Incidentally, therefore, and in a wide glance, we 

 see how the extension of zoological knowledge may become 

 one with the widening of commerce, and the increase of 

 many branches of profitable industry. 



But wider, more typical, and far more striking, are the 

 aspects in which zoology may become related not only to the 

 conservation and protection of our much-cherished indus- 

 tries, but to that highest of all human aims the conservation 

 and saving of human life itself. Did time permit, I could 

 lead you in an historical ramble backwards to the middle of 

 the seventeenth century, and southwards in imagination to 

 the still beautiful city of Florence, where a certain philosopher- 

 physician, by the name of Francesco Redi, started a contro- 

 versy, the part fruits of which you and I are reaping in this, 

 nineteenth century, and the fuller benefits of which our 

 descendants will assuredly in their turn gain. Redi directed 

 his attention to the solution of the question, whether or not 

 it were possible that living beings could come from things 

 that were dead or inorganic ; and gave it as his opinion, and as 

 the result of niuch careful investigation, that every living form 

 must have originated from something living which preceded 

 it in other words, that every animal must have had a parent, 

 and that every plant must have come from a pre-existing 

 plant. Prior to Redi's time it had been believed that living 

 things might and did spring from lifeless material. The 

 ancients and his predecessors, for example, believed that the 

 maggots appearing in putrifying meat were generated de 



