TRANSMUTABLE. 97 



1. The human blood-disc has special characters 

 of its own, by which it can be distinguished 

 from that of every other animal; so much so, 

 that a good microscopist is able to swear in 

 a court of justice that the stain he is shewn 

 is that of human blood. 2. Each class or 

 genus of animals has also a specially-characterized 

 blood-disc. Thus, that of the Cervus Eevisii is 

 only one six thousand three hundred and thirtieth 

 of an inch in diameter, that of the elephant one 

 two thousand seven hundred and forty-fifth of 

 an inch. In birds, reptiles, and fishes, they 

 are no longer circular, but oval. In birds the 

 long diameter is one two thousand and fifth, by 

 one three thousand three hundred and sixty- 

 ninth. In frogs one thousand one hundred and 

 eighth long, by one thousand eight hundred and 

 twentieth short. The corpuscle of the proteus 

 is twice as large as that of the frog, which is 

 three times as large as that of man! Among 

 the invertebrate class, the blood corpuscle of the 

 earth-worm is a thousandth part of an inch in 

 length, by one thousand two hundredth broad. 

 The leech one three thousandth long, by one 

 three thousand six hundredth broad. 



Surely a contemplation of facts like these 

 must set at rest for ever the possibility of any 

 " variation" of structure being at the foundation 

 of the origin of species. 



Still keeping to the anatomy of the human 

 body, I might carry the blood into the lung, 

 and describe the various processes which are 



