198 DESIGN IN NATURE 



processes of inorganic nature with the mental hfe of the highest animals. For all these phenomena — indeed, for 

 all phenomena both in nature and in the mind — Lamarck takes exclusively mechanical, physical, and chemical 

 activities to be the true efficient causes. Darwin refers them to natural selection. . . . All the phenomena of 

 the psychic life are, without exception, bound up with certain material changes in the living substance of the body, 

 the frotoflasm. We have given to that part of the protoplasm which seems to be the indispensable substratum 

 of psychic life the name of fsychoflasm (the soul-substance in the monistic sense) ; in other words, we do not 

 attribute any peculiar ' essence ' to it, but we consider the psyche to be merely a collective idea of all the psychic 

 functions of protoplasm. In this sense the ' soul ' is merely a physiological abstraction like ' assimilation ' or 

 ' generation.' . . In the unicellular protista, the psychoplasm is identified either with the whole of the living 

 protoplasm of the simple cell or with a portion of it. In all cases, in the lowest as well as the highest stages of 

 the psychological hierarchy, a certain chemical composition and a certain physical activity of the psychoplasm 

 are indispensable before the ' soul ' can function or act. That is equally true of the elementary psychic function 

 of the plasmatic sensation and movement of the protozoa, and of the complex functions of the sense-organs and 

 the brain in the higher animals and man. The activity of the psychoplasm, which we call the ' soul,' is always 

 connected with metabohsm. ... All living organisms without exception have the faculty of spontaneous movement, 

 in contradistinction to the rigidity and inertia of imorganised substances (for example, crystals) ; in other words, 

 certain changes of place of the particles occur in the hving psychoplasm from internal causes, which have their 

 source in its own chemical composition. ... At the lowest stage of organisation, in the lowest protists, the 

 stimuli of the outer world (heat, hght, electricity, &c.), cause in the indifferent protoplasm only those indispensable 

 movements of growth and nutrition which are common to all organisms and are absolutely necessary for their 

 preservation. That is also the case in most of the plants. . . . The automatic and the reflex movements which 

 we observe everywhere, even in the unicellular protists, seem to be the outcome of inchnations which are insepar- 

 ably connected with the very idea of Hfe. Even in the plants and lowest animals these inchnations, or tropisms, 

 seem to be the joint outcome of the inchnations of all the combined individual cells. When two cells meet as 

 a result of copulation, or when they are brought into contact through artificial fertilisation] (in the fishes, for 

 instance), they attract each other and become firmly attached. The main cause of this cellular attraction is a 

 chemical sensitive action of the protoplasm, allied to smell or taste, which we call ' erotic chemicotropism ' ; it may 

 also be correctly (both in the chemical and the romantic sense) termed cellular afiinity or ' sexual cell-love.' On 

 a critical study of these different embryonic formations, the evolution of which from each other we can directly 

 observe under the microscope, we arrive, by means of the great law of biogeny, at a series of most important con- 

 clusions as to the chief stages in the development of our psychic Hfe. We may distinguish (1) UniceUular protozoa 

 with a simple cell-soul : the infusoria. (2) Multicellular protozoa with a communal soul : the catallacta. (3) The 

 earliest metazoa with an epitheUal soul : the platodes. . . . The earliest ancestors of man and all other animals 

 were unicellular protozoa. This fundamental hypothesis of rational phylogeny is based, in virtue of the phylo- 

 genetic law, on the familiar embryological fact that every man, Hke every other metazoon (that is, every multi- 

 cellular organism with tissues), begins his personal existence as a simple cell, the stem-cell (cytula), or the 

 impregnated egg-cell. As this cell has a ' soul ' from the commencement, so had also the corresponding unicellular, 

 ancestral forms, which were represented in the oldest series of man's ancestors by a number of different protozoa. 

 . . . Every living cell has psychic properties, and the psychic Hfe of the multicellular animals and plants is merely 

 the sum-total of the psychic functions of the cells which build up their structure. In the lower groups (in algse 

 and sponges for instance) all the cells of the body have an equal share in it (or with very slight differences) ; in 

 the higher groups, in harmony with the law of the ' division of labour,' only a select portion of them are involved 

 — ' the soul-cells.' . . . We find the highest development of the animal cell-soul in the class of ciliata, or ciHated 

 infusoria. The unicellular protozoa give proof of the possession of a highly-developed ' cell-soul,' which is of great 

 interest for a correct decision as to the psyche of our earHest unicellular ancestors. . . . The tissue-soul (histo- 

 psyche) : in all multicellular, tissue-forming plants (metaphyta) and in the lowest, nerveless classes of tissue-forming 

 animals (metazoa) we have to distinguish two different forms of psychic activity — namely (1) the psyche of the 

 individual ceHs which compose the tissue, and (2) the psyche of the tissue itself, or of the ' cell-state ' which is 

 made up of the tissues. This ' tissue-soul ' is the higher psychological function which gives physiological indi- 

 viduaHty to the compound multicellular organism as a true ' cell-commonwealth.' It controls all the separate 

 ' cell-souls ' of the social cells — the mutually dependent ' citizens ' which constitute the community. . . . The 

 plant-soul [phytopsyche) is, in our view, the summary of the entire psychic activity of the tissue-forming multi- 

 cellular plant (the metaphyton, as distinct from the unicellular protophyton). . . The soul of the nerveless metazoa. 

 Of very special interest for comparative psychology in general, and for the phylogeny of the animal soul in 

 particular, is the psychic activity of those lower metazoa which have tissues, and sometimes differentiated organs. 



