NATURE AND CONDITIONS OF LIFE. II 



The only other condition of life which need be noticed is 

 the presence of "organisation" in living bodies; and the im- 

 portance of this has been greatly reduced by the progress of 

 modern science. All the higher forms of life are " organised," 

 that is to say, they possess distinct parts or "organs," which 

 have certain definite relations to one another, and which dis- 

 charge certain definite offices or " functions." The protoplasmic 

 and actually living portions even of these, however, appear, 

 under the highest powers of the microscope, to be destitute of 

 any recognisable structure, and are therefore not " organised." 

 Moreover, many of the lowest forms of life (such as the Fora- 

 minifera amongst the Protozoa) fail to fulfil one of the most 

 essential conditions of organisation, being mostly or wholly 

 devoid of definite parts or organs. Nevertheless, they are 

 capable of manifesting all the essential phenomena of life ; they 

 are produced from bodies like themselves ; they eat, digest, 

 and move, and exhibit distinct sensibility to many external im- 

 pressions. Furthermore, many of these little masses of struc- 

 tureless jelly possess the power of manufacturing for them- 

 selves, of lime, or of the still more intractable flint, external 

 shells of surpassing beauty and mathematical regularity. In 

 the face of these facts we are therefore compelled to come to 

 the conclusion that life is really the cause and not the conse- 

 quence of organisation ; or, in other words, that organisation is 

 not an intrinsic and indispensable condition of vital phenomena. 

 While it is generally admitted that " organisation," in the ordi- 

 nary acceptation of this term, is not essential to the manifesta- 

 tion of vitality, there are high authorities who consider that 

 the great differences in the vital phenomena of different or- 

 ganisms are due to differences in the " molecular complexity " 

 of the protoplasm forming the bodies of these. Apart, how- 

 ever, from the fact that such differences in " molecular com- 

 plexity" are, and must remain, hypothetical, this view can 

 hardly be regarded otherwise than as a revival, in another form, 

 of the theory that vital phenomena are the result of the or- 

 ganisation of the living body; since "molecular complexity" 

 is only "organisation," with the "organs" so minute as to 

 evade the highest powers of the microscope. 



As to the precise relations which subsist between the " phy- 

 sical basis of life " and the phenomena of vitality, it is held by 

 some that " life " is one of the properties of the albuminous 

 body which we term protoplasm. On this view, life is a form 

 of energy or motion, due simply to molecular movements tak- 

 ing place in the ultimate molecules of the protoplasm, and 



