304 DESIGN IN NATURE 



the distinguishing feature ; they are the counterparts of endosmose and exosmose, and of all the give-and-take 

 movements, which are necessary to absorption and assimilation, to secretion and excretion. They are the 

 ways and means which enable plants and animals to take in their natural pabulum, whether solids, liqmds, or 

 gases, and to give out the detritus or waste products, which are a consequence of every form of metabolism 



in hving things. 



When the mass of plasmodium advances and retires it is permeated by a large number of active, branchmg 

 streams ; the currents of which are, in many cases, extremely rapid. The currents of the larger streams are 

 swifter than those of the smaller ones. When any stream meets with an obstruction which it cannot remove, col- 

 lateral streams are at once estabhshed, which impresses one with the idea that the streams are under control, and 

 can be increased and diminished at pleasure. They apparently can also be quickened and slowed. The collateral 

 streams resemble those which follow the hgature or obstruction of an artery. The appearance presented by the 

 streams and currents in question reminds us of analogous currents witnessed in growing tissues, where branching 

 vessels, the result of cell formation and absorption, appear in suitable positions in definite areas. 



Examples of these currents and formations are seen in the developing ovum, chick, bone, &c. 



This is a subject fraught with great interest, as the stream formations of plasmodium are vital and purposive, 

 like the streams of blood and other fluids in young tissues. They are also dendritic in character ; the dendritic 

 arrangement not being confined to the organic kingdom, but extending to the inorganic kingdom. As a matter 

 of fact, the dendritic arrangements and formations may be the outcome of either vital or physical force. The 

 dendritic streams of plasmodium, the branching streams of fluids in plants and animals (with or without vessels), 

 and the dendritic flow of nerve impulses in branching nerve cells are essentially vital in their nature ; the dendritics 

 of hghtning and of frost on window-panes, pavements, &c., being, on the other hand, purely physical. As has been 

 already explained, the living and dead are inextricably blended, and life can only work through death and dead 

 material. Moreover, and as already stated, when Hving matter appropriates dead matter it also appropriates, within 

 hmits, the force which inheres in the appropriated matter, so that there is a certain degree of " oneness " in the 

 forms and movements of organic and inorganic matter. 



This explains, to a large extent, the symmetry of structure which prevails in plants and animals and in many 

 inorganic forms. 



The curious and striking phenomena exhibited by the plasmodium of Badhamia lUricularis can be most con- 

 veniently studied by cultivating portions of the organism in glass cases and beneath bell jars, as under these circum- 

 stances the specimens can be examined at all times by the naked eye or by the aid of the microscope. They can 

 also be voluntarily thrown into the inactive, resting or sclerotium stage, or into the advancing, aggressive, active stage. 



It is a surprising fact that an organism composed largely of protoplasm with an admixture of cells, nuclei, 

 and nucleoh and no well-defined structure, can exhibit such a variety of movements and discharge such a multi- 

 pUcity of functions ; and, it appears to me, the time has now come when fresh and exhaustive studies of life in 

 its most rudimentary and lowest forms must be made, if life in its highest manifestations is to be intelUgently 

 estimated. That masses of living material, large or small, protoplasmic or otherwise, should display amoeboid and 

 rhythmic movements, should wake and sleep or hibernate, should feed and discharge waste products at intervals, 

 should virtually secrete and excrete, should reproduce and perpetuate themselves, and, in a way, discharge all the 

 functions discharged by the highest animals, are matters of primary importance in every form of biological and 

 physiological inquiry. 



As a matter of fact, the higher plants and animals are, numerically, exceedingly small as compared with the 

 teeming millions of lower plant and animal forms everywhere met with — animalcules, bacteria, microbes, &c., &c. 

 In all of these, living matter and function and the potentialities of both can be witnessed and studied. The amount 

 of life on the earth is incredibly great, but life does not exist as apart from structure and function ; differentiation 

 occurring in both until man is reached. Without the potentialities of living matter no progress could be made 

 either as regards structure or function ; hence the absolute necessity for studying living matter in its simplest forms 

 and most incipient beginnings. 



The difficulties connected with this subject are well-nigh insuperable, alike because of the number and 

 minuteness of the organisms to be investigated. To take one example. Microbes in malaria and other fevers 

 swarm in the blood and actually inhabit the red blood-corpuscles, which corpuscles in man are so minute that they 

 only measure from yjTrVo to joVu of an inch in diameter. The number of microscopic living things in the air, 

 the water, and the soil is legion. 



In these the very mainsprings of existence are concealed. In plants and the lower and lowest animals are 

 stored up in a latent or potential form the undefined structures and functions which characterise the highest animals, 

 man included. In the highest animals we are called upon to deal with well-defined, differentiated structures in 



