Notices of New Books. 7595 



lead. The metals can also be subdivided into a number of natural 

 groups, defined by correlated affinities, as that including the metals 

 resembling platina, and the group of metals having oxides with acid 

 properties ; in fact, the affinities and correlationships of all the elements 

 < are endless, and to outward resemblance they possess more common 

 blood than either of the organic kingdoms. There is another uncon- 

 nected parallelism which must here be noticed, the resemblance in 

 the kinds of properties existing within the two organic kingdoms. Mr. 

 Darwin may perhaps attribute them to genealogical relationship, as 

 he claims the possibility of the common origin of animals and vege- 

 tables; but it would be obviously necessary, on his theory, that any 

 organs or functions, common to the two kingdoms through affinity, 

 should have been developed by the process of natural selection before 

 their divergence. One of the many common properties shared by the 

 two kingdoms is that wonderful and mysterious phenomenon, sexuality. 

 Now all naturalists, even those that assume their community in their 

 lowest forms, admit that the animal and vegetable kingdoms diverge 

 long before the sexual element appears ; that is, that a large series of 

 plants and animals, far above the stage in which the animal and vege- 

 table kingdoms are possibly identical, are asexual ; so that, even 

 admitting, for the sake of argument, that plants and animals have gra- 

 dually progressed from a common origin, sexuality in plants and sexu- 

 ality in animals are genealogically independent, and aSbrds another 

 striking example of unrelated analogy. A somewhat similar case pre- 

 sents itself in the abortive teat in the male mammal ; here is an 

 organ utterly fnnctionless, and if it is not an aborted once useful 

 organ it cannot have been developed by natural selection ; it cannot 

 be an aborted organ resulting from the separation of the sexes, because 

 sexuaUty, or the distinction between male and female, appears much 

 lower in the scale of creation than the teat-bearing mammal, and the 

 teat, as an organ of nutrition concomitant with parturition, would, on 

 the principle of natural selection, have been perfected in the one sex 

 only. 



Mr. Darwin refers to an apparent difficulty somewhat parallel with 

 the above, and we notice it to show how easily we may be misled 

 in assuming certain points of organization as the gradual effects of 

 use for particular purposes. We refer to the composition of the skull 

 out of distinct bones, apparently for the purpose of its temporary 

 contraction in parturition. Such may be the case, but not as the 

 result of gradual modification by use ; for we find them repre*sented 

 by corresponding marks, when the growth of bone takes place, in 



