GENERAL LAW OF ANIMAL FERTILITY. 585 



its general view is Dr. Carpenter's description of the multiplica- 

 tion of vegetable cells, which he says divide, " in virtue, it may 

 be surmised, of a sort of mutual repulsion between the two 

 halves of the endochrome (coloured cell-contents) which leads to 

 their spontaneous separation." * Under a modified form of this 

 process, the cell-contents, instead of undergoing bisection, divide 

 into numerous parts, each of which ultimately becomes a separate 

 individual. In some of the Algae " a whole brood of young cells 

 may thus be at once generated in the cavity of the parent-cell, 

 which subsequently bursts and sets them free." f The Achlya 

 prolifera multiplies after this fashion. Amongst the Fungi, too, 

 the same mode of increase is exemplified by the Protococcus nivalis. 

 And " it would appear that certain Infusoria, especially the 

 Kolpodince, propagate by the breaking-up of their own mass into 

 reproductive particles." J 



Now in this fissiparous mode of multiplication, which "is 

 amazingly productive, and indeed surpasses in fertility any other 

 with which we are acquainted," we see most clearly the anta- 

 gonism between individuation and reproduction. We see that 

 the reproductive process involves destruction of the individual ; 

 for in becoming two, the parent fungus or polygastrian must be 

 held to lose its own proper existence ; and when it breaks up 

 into a numerous progeny, does so still more completely. More- 

 over, this rapid mode of multiplication not only destroys the in- 

 dividuals in whom it takes place, but also involves that their in- 

 dividualities, whilst they continue, shall be of the lowest kind. 

 For assume a protozoon to be growing by imbibition at a given 

 rate, and it follows that the oftener it divides the smaller must 

 be the size it attains to ; that is, the smaller the development of 

 its individuality. And a further manifestation of the same truth 

 is seen in the fact that the more frequent the spontaneous fission 

 the shorter the existence of each individual. So that alike by 

 preventing anything beyond a microscopic bulk being attained, by 

 preventing the continuance of this in its integrity beyond a few 

 hours, and by be, tig fatal when it occurs, this most active mode of 

 reproduction shows the strongest antagonism to individual life. 



6. Whether or not we regard reproduction as resulting from 

 a repulsive force (and, as seen above, both Owen and Carpenter 

 lean to some such view), and whether or not we consider the 

 formation of the individual as due to the reverse of this an 

 attractive force we cannot, on studying the phenomena, help 

 admitting that two opposite activities thus generalized are at 



* Prin. ofPhys., p. 92. f Ibid., p. fl3. f Ibid., p. 91 T. 



" A General Outline of the Animal Kingdom." By Prof. T. R. Jones, 

 F G. S,p. G 1 .. 



