and coalesce , and the resulting amoeba swims away as two individ uals rolled into one. Now in this case what became of the individuality of each amoeba ; did amoeba A eat amoeba B , or vice versa , and is the re sulting amoeba a survival of A or of B or of both , or of neither of them ? j And what becomes of the antithesis of < ' ' eating or being eaten , ' ' which was / so clear and distinct in the highly specialized forms of life , and is so evanescent in the simpler forms ? i This illustration may serve to teach ( us how necessary it is to trace things up to their origins , before expressing too confident opinions as to their nature and relations. Life and Matter. In the case of the organic or inorganic - ' " organic worlds the proper course obviously - ' viously is , not to draw conclusions from extreme and highly specialized instances , but to follow life down ward to its simplest and most primi tive form , and to trace matter up ward to the stage which approaches most nearly to the living form of life. Following matter upward , we find a regular progression from the simple to the complex. Take the diamond , which is one of the simplest of sub stances , being merely the crystalized form of a single ultimate element , carbon. It is extremely hard and ex tremely stable. Ascending to com pounds of two , three or more elements , we get substances which are more complex and less stable ; and at last wo arrive at combinations which in volve many elements and are most complex. Among these latter sub stances arc some , called colloids , which are neither solid , like crystals , ror fluid , like liquids , but in an in termediate state , like jelly , or the white of an egg , in which the mole cules have great mobility and are at a considerable distance apart , so that water can penetrate their mass. These colloids are for the most part very complicated compounds of vari ous elements based on a nucleus of carbon , which from its atom having four poles with strong mutual attrac tions , is eminently qualified for form ing what may be called the inner skel eton of these complex combinations. Colloids of this description supply the last stage of the ascending line from inorganic matter to organic life. Next , let us trace life downward to ward matter. There is a constant sucession from the more to the less complex and differentiated ; from man through mammals , reptiles , fish es , and a long chain of more simple forms , until at its end welcome to the two last links , which are the same for all animals , all plants , and all forms of animated existence. The last link but one is the cell , the last of all is protoplasm. Protoplasm , called by Huxley "the physical basis of life , " is a colorless jelly-like substance , ab solutely homogeneous , without struc ture , in fact a mere microscopic speck of jelly. The cell is the first stop in the specialization of protoplasm , the outer layer of which , in contact with the surrounding environment , becomes hardened so as to form a cell-wall , while a portion of the enclosed proto plasm condenses into a nucleus , in which a further condensation makes what is called the nucleolus or second smaller nucleus. This constitutes the nucleated cell , whoso repeated subdi vision into other similar cells in geometrical metrical progression furnishes the raw material out of which all the varied structures of the world of life are built up. Plants and animals , bones , muscles , and organs of sense , are all composed of modified cells , hardened , flattened or otherwise altered , as the case may require. If we trace life up to its or igin in the same individual , instead of in the species , we arrive at the same result. All plants and animals , wheth er of the lowest or highest forms fish , reptile , bird , mammal , man begin their individual existence as a speck of protoplasm , passing into a nucle ated cell , which contains in it the whole principle of its subsequent evolution lution into the mature and completed form. Protoplasm is , therefore , evi dently the nearest approach of life to matter ; and if life , when the world was in a different chemical condition from what it is now , ever originated from atomic and molecular combina tions , it was in this form. To suppose that any more complicated form of life , however humble , could originate from chemical combinations , would be a violation of the law of evolution , which shows a uniform 'development from the simple to the complex , and never a sudden jump , passing at a bound over intermediate grades. To understand life , we must understand protoplasm ; for protoplasm , closely as it approximates to colloid matter , is thoroughly alive. A whole family , the monera , consists simply of a living globule of jelly. Every molecule , as in a crystal , is of homogeneous chemi cal composition and an epitome of the whole mass. There are no special parts , no organs told off for particular functions , and yet many life-functions nutrition , reproduction , sensation , and movement are performed , but each by the whole body. The jelly speck becomes a mouth to swallow , and turning inside out a stomach to digest. It shoots out tongues of jelly to move and feel with , and presently withdraws them. With these attri butes it is impossible to deny to proto plasm the full endowment of the low est class of life , or to doubt that , like the atom in the material world , it is the primary element of organic , or OfA' < aff'fJ lK3ffI I living existence. Given this atom , wo can trace up , step by step , the whole evolution of matter ; so given the protoplasm , we can trace up the evolution of life by progressive stages to its highest development man. Protoplasm. What is protoplasm ? In its sub stance it is a nitrogenous carbon com pound , differing only from other sim ilar compounds of the albuminous fam ily of colloids by the extremely com plex nature of its molecules. It con sists of five elements , and its average composition is believed by chemists to be 52.55 per cent carbon , 21.28 oxy gen , 15.17 nitrogen , 6.7 hydrogen , 1.2 sulphur. Its peculiar qualities , there fore , including life , are not the result of any new and peculiar atom added to the known chemial compounds of the same family but of the manner of grouping and motions of these well- known material elements It has in a remarkable degree the faculty of ab sorbing water , so that its molecules seem to float in it in a condition of semi-fluid aggregation , which ap pears essential to the molecular mo ments which are the cause or the ac companiment of life. Thus , many seeds if perfectly dry , may remain for months apparently as dead and as unchanging as crystals , to revive into life when moistened. But , * in addition to those material qualities in which protoplasm seems to differ only from a whole group of similar compounds of the type of glyc erine , by the greater complexity and mobility of its molecules , it has de veloped the new and peculiar element which is called life , and which has been defined by the late Dr. Oliver Wendell Holmes as "the state of an organized being in which it maintains , or is capable of maintaining its struc tural integrity by the constant inter change of elements with the surround ing media. ' ' In its essence , life is manifested by the faculties of nutri tion , sensation , movement and repro duction. As regards nutrition , there is this essential difference between living and non-living matter. The latter , if it feeds and grows at all , does so only by taking on fresh mole cules of its own substance on its outer % surface , as in the case of a small crys tal of ice in freezing water. If it feeds on foreign matter and throughout its mass , it does so only in the way of chemical combination. Living matter - tor , on the other hand , feeds internal ly , and works up foreign substances , by the process we call digestion , in to molecules like its own , which it assimilates , rejecting as waste any surplus or foreign matter which it cannot incorporate It thus grows or decays as assimilation or waste pre ponderates , remaining always itself. The distinction will be clear if we X lKi vA * m