INADEQUACY OF NATURAL SELECTION, ETC. ^43 



measure relative mortalities, we must assume the conditions to be 

 the same and must use the same measure. Let us do this with 

 some appropriate animal — say Man, as the most open to observa- 

 tion. The mortality of the somatic cells constituting the mass of 

 the human body, is, according to Professor Weismann, shown by 

 the decline and final cessation of cell-multiplication in its various 

 organs. Suppose we apply this test to all the organs : not to 

 those only in which there continually arise bile-cells, epithelium- 

 cells, etc., but to those also in which there arise reproductive 

 cells. What do we find ? That the multiplication of these last 

 comes to an end long before the multiplication of the first. In 

 a healthy woman, the cells which constitute the various active tis- 

 sues of the body, continue to grow and multiply for many years 

 after germ-cells have died out. If similarly measured, then, these 

 cells of the last class prove to be more mortal than those of the 

 first. But Professor Weismann uses a different measure for the 

 two classes of cells. Passing over the illegitimacy of this pro- 

 ceeding, let us accept his other mode of measurement, and see 

 what comes of it. As described by him, absence of death among 

 the Protozoa is implied by that unceasing division and subdivision 

 of which they are said to be capable. Fission continued without 

 end, is the definition of the immortality he speaks of. Apply 

 this conception to the reproductive cells in a Metazoon. That the 

 immense majority of them do not multiply without end, we have 

 already seen : with very rare exceptions they die and disappear 

 without result, and they cease their multiplication while the body 

 as a whole still lives. But wnat of those extremely exceptional 

 ones which, as being actually instrumental to the maintenance 

 of the species, are alone contemplated by Professor Weismann ? 

 Do these continue their fissiparons multiplications without end ? 

 By no means. The condition under which alone they preserve a 

 qualified form of existence, is that, instead of one becoming two, 

 two become one. A member of series A and a member of series B, 

 coalesce ; and so lose their individualities. Now, obviously, if the 

 immortality of a series is shown if its members divide and sub- 

 divide perpetually, then the opposite of immortality is shown 

 when, instead of division, there is union. Each series ends, and 

 there is initiated a new series, differing more or less from both. 

 Thus the assertion that the reproductive cells are immortal, can be 

 defended only by changing the conception of immortality other- 

 wise implied. 



Even apart from these last criticisms, however, we have clear 

 disproof of the alleged inherent difference between the two classes 

 of cells. Among animals, the multiplication of somatic cells is 

 brought to an end by sundry restraining conditions ; but in various 

 plants, where these restraining conditions are absent, the multi- 



