that we must believe these germs to have arisen as a modification of inorganic matter by "natural causes."

What the theory really is may be more fully understood by reference to the views of the most * prominent of the scientific men who have, in whole 'or in part, adopted it; and it will be seen that they do not always harmonize with each other or with Darwin.

Prof. Owen made a distinction between “Derivation" and natural selection, and advocated the former. He said: "Derivation recognizes a purpose in the defined and pre-ordained course due to innate capacity or power of change by which created Protozoa, have risen to the higher forms of plants and animals." "Derivation holds that every species changes in time by virtue of inherent tendencies thereto. Natural selection holds that no such change can take place without the influence of altered external circumstances educing or selecting such change." "So being unable to accept the volitional hypothesis, or that of impulse from within, I deem an innate tendency to deviate from parental type, operating through periods of adequate duration, to be the most probable nature or way of operation of the secondary law, whereby species have been derived one from another." (6-51).

From this it would seem that one species was derived from another, in a rising scale of advancement under the pressure of an "innate capacity,"

cult to see much difference between this and the "impulse from within" of the "Vestiges." Darwin, however, does not assent to this. He

says:

"Natural selection includes no necessary or universal law of advancement or development,' but "only takes advantage of such varieties as arise and are beneficial to each creature under its complex relations of life." (2-119). In other words, it is a mere struggle for existence coupled with changing conditions.

Prof. Kölliker, cited by Huxley, said: (7–310, 311).

"The fundamental conception of this hypothesis is, that under the influence of a general law of development the germs of organisms produce others different from themselves. This might happen (1) by the fecundated ova passing, in the course of their development, under particular circumstances, into higher forms; (2) by the primitive and later organisms producing other organisms, without fecundation, out of germs or eggs (Parthenogenesis). "It is obvious that my hypothesis is very similar to that of Darwin's, inasmuch as I consider that the various forms of animals have proceeded directly from one another, My hypothesis of the creation of organisms by heterogeneous generation, however, is distinguished very essentially from Darwin's by the entire absence of the principle of useful variations, and their natural selection; and my fundamental conception is, that a great plan of de

of the organic world, impelling the simple forms to more and more complex developments. How this operates, what influences determine the development of the eggs and the germs, and impel them to assume constantly new forms, I cannot pretend to say; but I can at least adduce the great analogy of the alternation of generation. If a Bipennaria, a Brachiolaria, a Pluteus, is competent to produce the Echinoderm, which is so widely different from it; if a hydroid polyp can produce the higher Medusa if the vermiform. trematode nurse' can develop within itself the very unlike Cercaria, it will not appear impossible that the egg, or ciliated embryo, of a sponge, for once, under special conditions, might become a hydroid polyp, or the embryo of a Medusa, an Echinoderm."

Great plans are not of spontaneous generation, but must of necessity be formed by an intelligent power equal to their conception and fulfilment. If by the words, "A great plan," used in the above connection by Prof. Kölliker, he means that the Creator uses, or has used, simpler forms to create the more complex, he is much nearer the truth than he was himself aware. Otherwise, he does not in the least improve upon the "innate capacity," "inherent powers," "inscrutable mysteries," and other like phrases, used so frequently to express an utter inability to explain

*

* Recently my attention has been for the first time directed

cult to see much differene berveen this and the "impulse from within" of the Festives.

Darwin, however, does not assent to this. He says: "Natural selection in (in les no necessary or universal law of airanement or development,' but only takes advantage of stub varieties as arise and are beneficial to each creature under its complex relations of life.” 2-112. In other words, it is a mere struggle for existence ocupled with changing conditions.

Prof. Kölliker, cited by Huxley, said: 7-310, 311).

"The fundamental conception of this hypothesis is, that under the induence of a general law of development the germs of organisms produce others different from themselves. This might happen (1) by the fecundated ova passing, in the course of their development, under particular circumstances, into higher forms; (2) by the primitive and later organisms producing other organisms, without fecundation, out of germs or eggs (Parthenogenesis). "It is obvious that my hypothesis is very similar to that of Darwin's, inasmuch as I consider that the various forms of animals have proceeded directly from one another, My hypothesis of the creation of organisms by heterogeneous generation, however, is distinguished very essentially from Darwin's by the entire absence of the principle of useful variations, and their natural selection; and my fundamental conception is, that a great plan of de

of the organic world, impelling the simple forms to more and more complex developments. How this operates, what influences determine the development of the eggs and the germs, and impel them to assume constantly new forms, I cannot pretend to say; but I can at least adduce the great analogy of the alternation of generation. If a Bipennaria, a Brachiolaria, a Pluteus, is competent to produce the Echinoderm, which is so widely different from it; if a hydroid polyp can produce the higher Medusa if the vermiform trematode 'nurse' can develop within itself the very unlike Cercaria, it will not appear impossible that the egg, or ciliated embryo, of a sponge, for once, under special conditions, might become a hydroid polyp, or the embryo of a Medusa, an Echinoderm."

Great plans are not of spontaneous generation, but must of necessity be formed by an intelligent power equal to their conception and fulfilment. If by the words, "A great plan," used in the above connection by Prof. Kölliker, he means that the Creator uses, or has used, simpler forms to create the more complex, he is much nearer the truth than he was himself aware. Otherwise, he does not in the least improve upon the "innate capacity," "inherent powers," "inscrutable mysteries," and other like phrases, used so frequently to express an utter inability to explain

*

* Recently my attention has been for the first time directed