398 



SCIENCE 



[Vol. IV., No. 90. 



DEATH AND INDIVIDUALITY. 



The current conceptions of death as a bio- 

 logical phenomenon are very confused and 

 unscientific. In this essay I shall endeavor 

 to analyze the problem, and, hy placing the 

 factors concerned in a clearer light, to dimin- 

 ish the obscurity in which the subject is still 

 involved. This appears to me the more de- 

 sirable, because the recent publications of 

 Weismann and Goette upon this general topic 

 have increased rather than lessened the exist- 

 ing confusion. In fact, these authors fail to 

 make the necessary distinctions between the 

 different kinds of death, the different orders of 

 individuality, and the different forms of repro- 

 duction. This assertion is, I believe, justified 

 by the following paragraphs : — 



First, as regards individuality. Individual- 

 ity, as it is generally understood (i.e., as 

 something always equivalent to itself), does 

 not exist in nature, except subjectively as a 

 rather fantastic notion of the human mind. 

 The term ' individual ' is applied to things utter- 

 ly incommensurate with one another. An in- 

 dividual protozoon, an individual polyp, and 

 an individual insect, are not homologous and 

 comparable bodies. It is mere slavery to a 

 false form of speech to imagine that their 

 ' individuality ' is a common quality ; for, on 

 the contrary, the same word indicates here 

 three distinct phases. I know not how to 

 account for the immense significance attrib- 

 uted to the mystical idea of individuality, 

 which in reality corresponds onl}' to a physio- 

 logical capacit} r for a separate existence, but 

 in usage is tacitly assumed to be the name of 

 some vague fundamental property of life, 

 which, however, the mind cannot apprehend. 

 Now, we have renounced considering a wing 

 in a bee, a bird, or a bat, as identical or ho- 

 mologous with eveiy wing, either on account 

 of its name or its function. But, although 

 the different kinds of individuals of animals 

 and plants are much more unlike one another 

 than are the manifold types of wings, yet in- 

 dividuality is generally taken to mean a uni- 

 formly identical something ; and that is untrue. 

 Of course, the matter is really ver} T simple, and 

 indeed self-evident, as to its true nature ; and 

 the singular obscurity prevailing is probably 

 due only to the problem not having been clear- 

 ly thought over. At present the condition of 

 opinion upon the subject reminds one of the 

 ancient notions of beaut} T , according to which, 

 beauty was an inherent quality of objects, not 

 an impression of the mind, a psychological 

 state. Despite custom, it is plain that ' individ- 



ual' has man}* meanings ; yet it is usual to com- 

 pare ' individuals ' with one another through- 

 out the animal kingdom. This error has been 

 repeated by Weismann and Goette, because 

 thej' both assume that the death of a single 

 protozoon is equivalent to the death of one 

 of the higher animals. Goette, however, has 

 partially emancipated himself from this idea, 

 which I believe to be erroneous. The death 

 of a unicellular, is entirely different from the 

 death of a multicellular, individual. 



To Huxley 1 we owe the first scientific deter- 

 mination of individuality. His essay on the 

 subject ought to be thoroughly studied by every 

 biologist. Life occurs in c} r cles of cells ; each 

 cycle comprises all the cells springing from a 

 single impregnated ovum; the whole of every 

 C}*cle is homologous with every other whole 

 C3'cle, no matter whether every cell is a so- 

 called individual, or whether the}* constitute 

 several individuals (e.g., polyps) or a single 

 one (vertebrates). All cells are homologous, 

 all cycles are homologous ; but individuals are 

 not always homologous, since an individual 

 ma} r be either the whole or any fractional part 

 of a cycle. This question I have discussed a 

 little more fully on pp. 191, 192, of my article 

 cited in the footnote. 2 Manifestly the death 

 of the single cell is not necessarily identical 

 with the termination of a cycle. Now, when 

 a man, he being a cycle of cells, has lost the 

 abilit} r to continue the C}*cle, he (or it) dies. 

 Further, it is inherent in his constitution to 

 lose that ability gradually : hence, when it 

 is completely lost from internal causes, he 

 dies, as we say, from old age. It is to this 

 ending-off of the cycle, from causes resident 

 in itself, I wish to restrict the term ' natural 

 death.' 



We have now two questions to pose : 1°. 

 Do all organisms belong to cell-cj'cles? 2°. 

 If so, are all oycles self-limited? In common 

 language, the second question would be, Is 

 death always the natural and inevitable ac- 

 companiment of life ? — an inquiry which ma} T 

 appear singular, but is none the less perfectly 

 sensible and legitimate. Weismann has an- 

 swered it with a negative. 



1°. I maintain the hypothesis that all or- 

 ganisms do develop in cycles, and only in 

 C} T cles ; which involves the assumption that 

 all living species begin their life-history with 

 an impregnated ovum or its equivalent. We 

 come, therefore, at once to the question of 



1 T. H. Huxley (1852) upon animal individuality, Royal 

 inst. proc, i. 184-189; Edinb. new phil. journ., liii. 172-177; 

 Ann. mag. nat. hist., 1852. 



2 C. S. Minot (1879), Growth as a function of cells, Proc. 

 Boston soc. nat. hist., xx. 190-201. 



