Are we, in our trial to establish the necessary connections, simply to draw upon our innate power of synthesis, again once more to stimulate the much-jaded faculty of mental constructiveness? Assuredly, if the material for the verification of any logical supposition had been extant, the master-minds, who have so admirably dealt with this great subject of synthetical continuity, would have left no material chasm unbridged. Are we to find what we are in need of by laying open to inspection the subtile intricacy of the sanctuary of life, by minutely investigating the intimate composition and working of the mysterious organ of centralization? Dazzled by the wonders of this marvelous fabric, the consummated fruit of the mighty tree of life, there is assuredly danger that we shall fail to catch any glimpses of its dark and lowly origin.
It is very natural, then, and appropriate, that, seeking a way out of our scientific perplexity, we should direct attention to the study of vitality in its least complicated forms, which manifest the properties of life, and at the same time do not confuse us with structural entanglements. For, wherever we find fixity of differentiated parts already established, there the difficulty begins. The organism gains the appearance of a mechanical contrivance, and we feel at once puzzled as to what is driving and what is driven in the living engine. We desire, then, if possible, to become acquainted with life before it has assumed any definite shape, before the manifoldness of its relations has acquired any degree of stability, or settled morphological expression.
The least complicated forms of life now known are perhaps motionless, non-nucleated corpuscles, which are observed to grow and to multiply by division. But vitality in these forms displays itself so torpidly, or at least so clandestinely, that microscopic investigation is incompetent to detect the nature of the changes that constitute their vital activity. Besides, these motionless corpuscles are probably all inclosed in a membranous envelope, which special structure must be regarded as an organic complication undesirable for our purpose.
Haeckel was the first to point out the most fascinating of all primitive beings; and he was the first also to recognize their true import in biology. He named them, on account of the entire homogeneity of their structure, Monera. It is now well known that monera consist of nothing but a flake or globule of uniform viscid material. Yet these unorganized specks of matter are most truly alive, for they are seen to move, to nourish themselves, to react on outward impressions, and to propagate their kind.
Here, then, we have all the fundamental properties of life, without any of its morphological complications. By dispensing, for once, with all elaborate equipment, and by executing her principal performances with such deliberate distinctiveness and openness, it is as if Nature were here purposely inviting us to penetrate her vital mysteries.
If we can only gain an actual insight into the conditions upon which