226 LAMARCKIAN HYPOTHESIS OP THE 



tlie part of those who question their legitimacy to explain ; 

 it is enough for us to know, that individuals of the family to 

 which the Acai'us belongs are so remarkable for their powers 

 of life, even in their fully developed stat(', as to resist, for a 

 time, the application of boiling water, and to live long in al- 

 cohol. We know, further, that the germs of the lower ani- 

 mals are greatly more tenacious of vitality than the animals 

 themselves, and that they may exist in their state of em- 

 bryoism in the most unthought of and elusive forms ; nay, 

 — as the recent discoveries regarding alterations of generation 

 have conclusively shown, — that the germ which produced the 

 parent may be wholly unlike the germ that produces its oJET- 

 spring, and yet identical with that which produced the parent's 

 parent. Save on the theory of a quiescent vitality, maintained 

 by seeds for centuries within a few inches of the earth's sur- 

 face, we know not how a layer of shell-sand or marl spread 

 over the bleak moors of Harris should produce crops of white 

 clover, where only heath had grown before ; nor how brakes 

 of doddered furze burnt down on the slopes of the Cromarty 

 Sutors should be so frequently succeeded by thickets of rasp- 

 berry. We are not, however, to give up the unknown, — that 

 illimitable province in which science discovers, — to be a wild 

 region of dream, in which fantasy may invent. There are 

 many dark places in the field of human knowledge, which even 

 the researches of ages may fail wholly to enlighten ; but no 

 one derives a right from that circumstance to people them 

 witli chimeras and phantoms. They belong to the philoso- 

 phers of the future, — not to the visionaries of the present 

 But while it is not our part to explain how, in the experi- 

 ments of Mr Weekes, the chain of life from life has been main- 

 tained unbroken, we can most conclusively show, that that 

 world of organized existence of which we ourselves form part, 

 is, and ever has been, a world, not of tame repetition, but 

 of endless variety. It is palpably not a world of AcaridcB of 



