THE EXTINCT MAMMALIA. 313 



What is the nature of physical sensibility ? In this planet, it 

 is found residing only in one form of matter, which has a slightly 

 varied chemical constitution, namely, protoplasm, so called from 

 a physical standpoint. Now, this world, as you all know, has 

 passed through many changes of temperature. Its early periods, 

 it is probable, were so very hot that protoplasm had a very poor 

 chance. Again, can we assume for a moment that this little speck 

 in the great universe is the only seat of life ? I suppose scarcely 

 any scientific man will venture to do so. If, therefore, life exists 

 in other planets, worlds, and systems, does it necessarily occupy 

 bodies of protoplasm in those different, remote spheres ? It would 

 be a great assumption. It is altogether improbable. The cer- 

 tainty is, that in those planets which are in proximity to the sun's 

 heat there could be no protoplasm. Protoplasm in the remote 

 planets would be a hard mineral, and near the sun it would be dis- 

 sipated into its component gases. So that, if life be found in other 

 parts of this universe, it must reside in some different kind of 

 material. It is extremely probable that the physical conditions 

 that reside in protoplasm might be found in other kinds of matter. 

 It is in its chemical inertness, and in its physical constitution, that 

 its adaptation to life resides ; and the physical constitution neces- 

 sary for the sustentation of life may be well supposed to exist in 

 matter in other parts of the universe. I only say the door is open 

 and not closed : any one who asserts that life can not exist in any 

 other material basis than protoplasm is assuming more than the 

 world of science will permit him to assume. And that it is con- 

 fined to this single planet, among the great systems of the universe 

 — that assumption will not for a moment be allowed. Therefore 

 the subject is one which allows us a free field for future investiga- 

 tion : it is by no means closed in the most important laws which 

 it presents to the rational thinker. I hope, also, if the evi- 

 dence in favor of this hypothesis of the creation of living forms 

 be regarded as true, that no one will find in it any ground for any 

 very serious modification of existing ideas on the great questions of 

 right and wrong, which have been long since known by men as a 

 result of experience, and without any other scientific demonstra- 

 tion whatsoever. 



