FERTILISATION OF THE OVUM 381 



(d) They are the product of a First Cause, and are in no way the result of accident. 



(e) They are living entities and are not to be confounded with automata in any form. 



(/) They are self-acting, and work out their destinies, under guidance, by spontaneous movements. 



(?) They occasionally die out, and when they do, their disappearance is due not to mischance but to a pre- 

 determined plan. The extinction of certain plants and animals at a given period does not interfere with nature's 

 general plan or with the identity or permanence of plants and animals. 



(h) The reproductive elements of plants and animals have a Ufe of their own, and are hving from the first. 

 They bring with them into the world the wherewithal to nourish them while they are developing. 



{i) There is a life of the individual and a life of the race, and both are persistent, although in varying degrees. 

 The duration of the Ufe of the race greatly exceeds that of the individual, but the one Hfe is inseparably bound up 

 with the other, both having a common source. 



(j) Limits have been set to the outward and inward workings of plants and animals, and the same is true of 

 the several parts of the inorganic kingdom. 



{h) The inorganic and organic kingdoms are the counterparts of each other, and the two are complementary 

 in the widest sense. They give to and take from each other at every point, both as regards matter and force. 



(1) Any little tendency there is to variation in plants and animals is sooner or later corrected by a well-marked 

 tendency to revert or breed back. This reversion contributes to the perpetuation of types and to the permanency 

 of plants and animals on the earth. 



The permanency and non-mixing of plants and animals here insisted on are seen at their birth, in their 

 development, and in their career generally. 



While everything in our planet is daily and hourly changing, the great flora and fauna practically remain 

 stable. Stability or permanency, under the circumstances, bespeaks guidance and the operation of forces and laws 

 directly referable to a First Cause. The existence of such a state of things can only be explained by pre-meditation 

 and design. 



The most striking feature connected with ova, cells, and nuclei is their ultimate composition. Do they possess 

 a common structure, and have they in their substance at birth or at any period of their life histories, actually or 

 potentially, a something which indicates a general plan according to types and a special descent, whereby each plant 

 and animal reproduces only itself ? 



The changes which occur in reproduction are far-reaching. They raise the very important and much-disputed 

 question of the homogeneity and oneness of the ovum, and the identity of the matter forming the atom, molecule, 

 cell, and nucleus in the embryos of plants and animals. Until the advent of the phenomenally high powers of the 

 microscope it was customary to speak of the ovum, cell, and nucleus as simple or differentiated. A cell wall, 

 nucleus, nucleolus, and cell contents or protoplasm were, as a rule, predicated. There were, however, endless dis- 

 putes as to which of the structures mentioned was the most important. The consensus of opinion was ultimately 

 in favour of protoplasm, which, variously designated and described, was regarded by the majority of biologists as 

 the " physical basis of Hfe," " the life stuff," &c. This protoplasm was considered simple, homogeneous, and 

 identical throughout its entire substance. It was maintained, with few exceptions, to be wholly undifferentiated. 

 This statement is no longer tenable, as chemical analysis has shown protoplasm to be heterogeneous, and to vary 

 markedly in ultimate composition. It may be accepted as an axiom, to which there is no exception, that differentia- 

 tion can only occur in heterogeneous substances. No differentiation is possible in absolutely simple bodies. In 

 living plants and animals " like produces hke." A simple cell plant or animal can be obtained from an undif- 

 ferentiated speck of protoplasm, but to get a differentiated organism, a heterogeneous, complex speck of matter must 

 be employed. The theory that everything, inorganic and organic, had a simple origin is a very fascinating and a very 

 old one. It was re-stated and ampUfied by M. Jean Lamarck in 1801, and received a fresh filhp from the writings 

 of Mr. Charles Darwin in 1859 and subsequently. It largely rejects a First Cause and design, and leans upon chance 

 as a main factor. It is denied by an ever-increasing number of advanced modern workers, and no longer holds 

 the supreme position it did. It is especially discredited by those who beheve in Ufe as a separate entity, and who 

 are opposed to spontaneous generation, utihtarianism, and opportunism. 



It is now a matter of common knowledge that the ovum and nucleus are complex to begin with, and that they 

 undergo the most extraordinary changes during the process of reproduction. There is in these facts warrant for 

 the belief that no part of the ovum is homogeneous and simple in the ordinary sense, and the same is true of the 

 ovum as a whole in all its stages, from its impregnation until the offspring reaches maturity (Plates Ixi. to Ixiv., and 

 Ixxxvi. to Ixxxix. inclusive). 



All this can have but one meaning. The generally accepted theory that the ovum is simple, homogeneous, and 

 identical is, when carefully examined, found wanting, and must give way to the pressure of accumulated recent facts. 



