TRANSFORMISM 223 



potentiality : there only does the protoplasm retain 

 all the properties which were possessed by the primitive 

 life-substance before it became heterogeneous, that is, 

 before nucleus and cytoplasm evolved. When part 

 of the primitive life-substance became secluded in a 

 nuclear envelope, it became, to that extent, shielded 

 from the action of the physical environment, and when 

 the organism became composed of multicellular tissues 

 this seclusion became more complete. Clothed in 

 the garments of the flesh, it was henceforth protected 

 from the shocks of the environment, and it became 

 the immutable germ-plasm. But for a very long 

 time before this evolution of tissues the naked life- 

 substance had been exposed to the action of external 

 physical agencies, and it had been modified by these 

 into very numerous forms of protoplasmic matter. 

 When multicellular plants and animals had been 

 evolved there were, therefore, not one, but many kinds 

 of life-substance in existence, and these have persisted 

 until to-day as the unchanging germ-plasmata of the 

 existing organisms. 



The Weismannian hypothesis of to-day, supported 

 and amplified, as it is, by subsidiary hypotheses, does 

 not make the same appeal to the student as did the 

 pristine and altogether attractive speculation of thirty 

 years ago. The analogy which it then presented 

 with the matured chemical theory of matter must 

 have been almost irresistible. Just as the indefinitely 

 numerous compounds of chemistry are only the per- 

 mutations and combinations of some of eighty-odd 

 different kinds of matter, so all the forms of life are 

 combinations and permutations of some of the many 

 different kinds of life-substance which came into 

 existence before the evolution of the multicellular 

 organism. And just as the chemical elements were 



