ORIGINATION OF LIVING BEINGS 55 



of the thickness of the earth's crust contains faithful records 

 of the past forms of life, and inasmuch as these differ 

 more and more as we go further down, it is possible 

 and conceivable that we might come to some particular 

 bed or stratum which should contain the remains of those 

 creatures with which organic life began upon the earth. 

 And if we did so, and if such forms of organic life were 

 preservable, we should have what I would call historical 

 evidence of the mode in which organic life began upon this 

 planet. Many persons will tell you, and indeed you will 

 find it stated in many works on geology, that this has been 

 done, and that we really possess such a record ; there 

 are some who imagine that the earliest forms of life of which 

 we have as yet discovered any record, are in truth the 

 forms in which animal life began upon the globe. The 

 grounds on which they base that supposition are these : - 

 That if you go through the enormous thickness of the earth's 

 crust and get down to the older rocks, the higher vertebrate 

 animals the quadrupeds, birds, and fishes cease to be 

 found ; beneath them you find only the invertebrate 

 animals ; and in the deepest and lowest rocks those remains 

 become scantier and scantier, not in any very gradual 

 progression, however, until, at length, in what are supposed 

 to be the oldest rocks, the animal remains which are found 

 are almost always confined to four forms, Oldhamia, 

 whose precise nature is not known, whether plant or animal ; 

 Lingula, a kind of mollusc ; Trilobites, a crustacean animal, 

 having the same essential plan of construction, though 

 differing in many details from a lobster or crab ; and 

 Hymenocaris, which is also a crustacean. So that you have 

 all the Fauna reduced, at this period, to four forms : one a 

 kind of animal or plant that we know nothing about, and 

 three undoubted animals two crustaceans and one mollusc. 

 I think, considering the organization of these mollusca 

 and Crustacea, and looking at their very complex nature, 

 that it does indeed require a very strong imagination to 

 conceive that these were the first created of all living 

 things. And you must take into consideration the fact 

 that we have not the slightest proof that these which we 

 call the oldest beds are really so : I repeat, we have not 

 the slightest proof of it. When you find in some places 

 that in an enormous thickness of rocks there are but very 

 scanty traces of life, or absolutely none at all ; and that 

 in other parts of the world rocks of the very same formation 



