That is to say, Natural Selection is just as ready to degrade as to elevate a creature, according to the actual requirements of the circumstances in which it is placed, and how far progress has been the rule, rather than stability or retrogression, is a question for geological history to determine. This we shall have to consider in our next chapter. It is likewise obvious that so far as the mere struggle for existence is concerned, a species each of whose individual members is but poorly furnished, may nevertheless flourish unimpaired on the mere strength of its fecundity. It is thus, says M. Blanchard,[223] that the lower forms of life continue to hold their own despite the enormous ravages to which they are subject. The herring, for example, affords food to all the fowls of the air and fish of the sea, over and above the myriads annually requisitioned by man. Yet its hosts show no sign of being exterminated or even reduced. Much the same is the case of the cod; but a tribe one individual of which has been known to produce nine million eggs does not require much in the way of coherent heterogeneity to ensure its survival. Thus it appears that of itself Darwinism affords no explanation whatever of the regular progression of life forms from lower to higher, to which the records of Nature bear witness, and which is the one solid fact suggesting the idea of Evolution. Such are some of the reasons which, on purely rational grounds, appear amply to justify those who decline to pledge their faith to Darwinism, in spite of the popularity it enjoys. But what is to be said of the phenomena cited as furnishing positive and unimpeachable evidence in its favour, which were mentioned above in our sketch of its main features? First as to the rudimentary, fragmentary, or vestigial organs so common in Nature. These, it is said, being of no possible advantage to their possessors, and often a serious disadvantage, can be explained only by supposing that they were serviceable in the past to the ancestral race whence these possessors are derived, and have since been superseded by other modifications of structure, so as to dwindle away by disuse. This, no doubt, seems a very plausible explanation, but it does not follow that we ought immediately to adopt it as a certainty, instead of setting ourselves to examine how it accords with all the facts. Nothing is more dangerous and less scientific than to be in a hurry to conclude that everything is certain which seems to ourselves probable, especially if it suits a theory of our own. Unfortunately, this law is too frequently more honoured in the breach than the observance. In the present instance, Professor Haeckel himself furnishes an example. He is quite sure that the rudimentary structures can have but one significance, and that they are fatal to the idea of purpose in Nature, the object of his special aversion, and so he has proposed a new term, "Dysteleology," to embody this idea, of which he says,[224]