SCIENCE-GOSSIP. 



131 



Species " ; and the reason given for the fact of 

 persistence of low/ forms is a reason why there 

 should be no higher forms at all : if fully accepted 

 it puts a stop to all progress. I will here give the 

 explanation in full, and then examine it in detail. 

 I have italicised parts of the following extract from 

 the "Origin of Species" to call special attention 

 to certain statements, and for convenience of 

 reference have put letters to others in connection 

 with the remarks which will follow. 



" Why have not the more highly developed 

 forms everywhere supplanted and exterminated 

 the lower ? Lamarck, who believed in an innate 

 and inevitable tendency towards perfection in all 

 organic beings, seems to have felt this difficulty so 

 strongly that he was led to suppose that new and 

 simple forms were continually being produced by 

 spontaneous generation. I need hardly say that 

 science in her present state does not countenance 

 the belief that living creatures are now ever 

 produced from inorganic matter. On my theory 

 the present existence of lowly organized productions offers 

 no difficulty ; {a) for natural selection includes no 

 necessary and universal law of advancement or 

 development, it only takes advantage of such 

 variations as arise and are beneficial to each 

 creature under its complex relations of life. 

 {b) And, it may be asked, what advantage, as far as 

 we can see, would it be to an infusorial animalcule 

 — to an intestinal worm, or even to an earthworm — 

 to be highly organized ? // it ivere no advantage, 

 these forms would be left by natural selection unimproved 

 or but little improved, and might remain for indefinite 

 ages in their present little advanced condition. And 

 geology tells us that some of the lowest forms, as 

 infusoria and rhizopods, have remained for an 

 enormous period in nearly their present state. 

 But to suppose that most of the many now exist- 

 ing low forms have not in the least advanced since 

 the first dawn of life would be rash ; for every 

 naturalist who has dissected some of the beings now 

 ranked as very low in the scale, must have been 

 struck with their really wondrous and beautiful 



organization Although organization on 



the whole may have advanced and be advancing 

 throughout the world, yet the scale will still 

 present all degrees of perfection ; [c) for the high 

 advancement of certain whole classes, or of certain 

 members of each class, does not at all necessarily 

 lead to the extinction of those groups with which 

 they do not enter into close competition, [d) In 

 some cases, as we shall hereafter see, lowly organ- 

 ized forms seem to have been preserved to the 

 present day from inhabiting peculiar or isolated 

 stations, where they have been subjected to less 

 severe competition, and where they have existed 

 in scanty numbers, which, as already explained, 

 retards the chance of favourable variations arising. 



" Finally, I believe that lowly organized forms 

 now exist in numbers throughout the world and 

 in nearly every class, from various causes, {e) In 

 some cases favourable variations may never have 

 arisen for natural selection to act on and accumu- 

 late. In no case, probably, has time sufficed for 

 the utmost possible amount of development. In 

 some few cases there may have been what we must 

 call retrogression of organization. (/) But the 

 main cause lies in the circumstance that, under 

 very simple conditions of life a high organization would 

 be of no service — -possibly would be of actual 

 disservice — as being of a more delicate nature, 



and more liable to be put out of order and thus 

 injured." 



{a) But is it true that Darwin's views do not imply 

 the necessity of an advance from lower to higher 

 forms ? It has been shown that abundant 

 variation is constantly taking place in all classes 

 of organic beings ; and there are no grounds 

 for assuming that any species at the present 

 day or in time past should be exempt from this 

 law of variation. If variation is constantly 

 going on, and the struggle for existence ever 

 taking place, as supposed by Darwin, is it 

 not a necessary consequence that there should be 

 always, and under every condition of life, some 

 of these variations better fitted to survive than 

 others ? If there is any truth in Darwin's 

 hypothesis, ought not these to be constantly 

 building up new races on the ruins of the unim- 

 proved individuals ? When the problem is to 

 account for the evolution of higher forms from 

 lower, it is necessary to suppose the progress was, 

 on the whole, towards higher organization. If 

 Lamarckism implies " an innate and inevitable 

 tendency towards perfection in all organic beings," 

 Darwinism strives after the same goal of per- 

 fection in living organisms by a weeding out of the 

 unfit, not less inevitable. Only, by the latter, the 

 constant progress has to be attained without 

 the "innate and inevitable tendency"; it must 

 be by the victory of the higher forms in the 

 struggle for existence which acts by life and 

 death — the evolution of a new form entailing 

 the destruction of that from which it is derived. 

 (&) This question appears unanswerable, but it 

 might equally be asked of any low forms of life 

 at present existing, some of which, on Darwinian 

 principles, must be supposed to be advancing; it 

 might with equal propriety be asked of the lowly 

 forms of the past — which are the hypothetical 

 ancestors of the higher forms of the present. 

 If the explanation is accepted as accounting for 

 the persistence of low forms of life, it must also 

 be accepted as a reason why no low form of life 

 should ever become more highly organized on the 

 principles of natural selection ; for there is nothing 

 in Darwin's explanation to show that it applies to 

 certain low forms of life and not to others. There 

 seems no reason to suppose, for example, that the 

 "infusorial animalcule," the intestinal worm, or the 

 earth-worm, are more specially fitted to their 

 present conditions than other organisms ; or that 

 any others would be more likely to reap benefit 

 from a higher organization than they actually 

 possess. Neither are there any grounds for the 

 belief that the organisms of past ages were less 

 fitted to their surroundings than those of to-day, 

 or more likely to benefit by a higher organization. 

 {c) This explains why existing low organisms 

 continue to exist at the present, but does not 



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