Ixxiv 



to these Mesozoic and Palaeozoic times ; and we know not yet what 

 further resemblances to old forms of life may yet be detected in 

 the vast field just opened to ns. 



The present explorations, full of interest and valuable as they 

 are, are insignificant compared with the vast area of the ocean ; so 

 that when we look at what has been accomplished in these tenta- 

 tive researches, we can only take them as indicative of the rich 

 mine that yet remains to be explored, and look forward to dis- 

 coveries that will probably modify and throw much new light on 

 the relations between the marine life of the present and the past. 



One of the great subjects which these researches may put before 

 us in this new light is, that instead of the imperfect record which 

 geology usually gives us of the life of the old world, with its in- 

 terrupted succession in local descent, we may have, if the hypo- 

 thesis of an area continuously submerged from the Cretaceous 

 period should prove true, the lineal descendants of some portion of 

 those creatures which lived in the Chalk seas. If so, naturalists 

 will be able to see the exact amount of changes wrought, and to 

 study in what direction they have been effected. "VVe shall see the 

 effects of continuity in time in conjunction with continuity of con- 

 ditions, and whether any and what new forms have been evolved, 

 and where no progress has been made. "We see already that the 

 Foraminifera, Sponges, and Echinoderms claim relationship with 

 their fossil antetypes, though in an unequal degree. How will the 

 fully ascertained results agree with the theory of Natural Selec- 

 tion ? Beautiful, ably handed, and ingenious as this theory is, it 

 seems to me — I will not say to fail, because I am not competent 

 to pronounce on the natural-history bearings ; but it fails to sa- 

 tisfy me. Natural Selection is founded primarily on Sexual Se- 

 lection ; and this latter seems to me an implant so strong, and 

 to have an object so definite, viz. that of maintaining the species 

 in full vigour, strength, and health, that, in the absence of any 

 more direct evidence to the contrary, I would believe in the force 

 of this law of life to perpetuate the special type unaltered, rather 

 than in a divergent natural selection, leading, concurrently with 

 changes of condition, to aberrant forms. We have had curious 

 and remarkable evidence of elasticity of structure in certain direc- 

 tions ; but does not the rebound, in almost all cases, show the 

 existence of a spring which, while it admits of considerable play, 

 tends to readjustment as soon as the restraint is removed. That 

 there have been gradual changes in structure in all classes of animal 



