SPIRAL STRUCTURES AND MOVEMENTS IN NATURE 99 



the other requires. The respiratory movements in plants and animals are give-and-take, interrupted movements, 

 occurring at stated intervals, and therefore rhythmic in character. 



Plants and animals, in addition to breathing, feed, and circulate their nutritious juices. The feeding and circu- 

 latory movements, like the respiratory ones, are give-and-take movements, that is, they occur in a certain order, 

 and at stated intervals. Plants and animals not only take in, assimilate, and circulate extraneous substances 

 rhythmically ; they also give out the detritus or waste products rhythmically. The give-and-take, rhythmic move- 

 ments referred to have to do with every change which occurs in plants and animals ; with the respiratory act, with 

 the circulation of gases and fluids, with the absorption and assimilation of food, with the extrusion of waste products, 

 with secretion and excretion, metaboUsm, &c. The give-and-take, rhythmic movements are provided for in the 

 very beginnings of hfe. The cells of plants and animals afford the necessary conditions. Vegetable and animal 

 cells are composed of a cell wall, a nucleus, and protoplasmic cell contents. The cell wall is porous, and provides 

 an osmotic medium. When the cells are exposed to moisture, gases, heat, &c., two opposite or give-and-take virtually 

 rhythmic currents are at once estabUshed ; there is the comparatively rapid ingoing or endosmotic nourishing current, 

 and the slower outgoing or exosmotic waste product current. This explains how a plant or an animal composed 

 of a single cell can hve, grow, attain maturity, and reproduce itself. Living matter, lower than cells, possesses the 

 same powers and exercises the same privileges. What is true of a single cell is true of every congeries of cells, and 

 of all the tissues and parts formed by cells, in the simplest and most complex plant and animal organisms. Give- 

 and-take movements are necessary to all. 



§ 17. Spiral Structures and Movements Universal in Nature. 



The next arrangement and order of movement to be considered is the spiral. As already stated, the spiral 

 formations and movements reveal themselves in the physical universe in a variety of forms ; in the spiral distri- 

 bution of nebulae, in the spiral water-spout, the spiral sand-storm, &c. 



Has this spiral distribution and spiral movement of the atoms and molecules of matter in space any counter- 

 part in plants and animals ? Most assuredly it has. The seeds of certain plants, and the ova and embryos of 

 certain animals, exhibit distinct spiral formations and movements. 



While we have spiral formations and movement at the very beginnings of plant and animal Hfe, these are 

 multipUed and emphasised as growth and development proceed ; the highest representatives of the organic 

 kingdoms providing the most numerous and striking examples. Thus in plants we find spiral cells, spiral hairs, 

 spiral vessels, spiral stems, spiral branches, spiral leaves, spiral flowers, spiral fruits, &c. We also find spiral 

 movements in climbing and other plants. 



Similar remarks are to be made of animals. In these, the muscles, bones, and joints are spirally constructed 

 and arranged; the heart, stomach, bladder, uterus, &c., also display spiral structure. All exhibit spiral movements. 

 The movements of walking, swimming, and flying are, in every instance, spiral in their nature. 



Locomotion for the most part consists of spiral, sinuous, double-curve, figure-of-8 movements. These move- 

 ments make their appearance in bacteria and the lower plant and animal forms. They occur in the cilia of infusoria 

 and other organisms, where they take part in tactile, feeding, and swimming operations. The cilia and sinuous 

 movements are not unfrequently met with on mucous and other surfaces, where they produce currents in given 

 directions. The double-curve movements can be traced through the whole series of creeping things. They are seen 

 to advantage in the wave movements of the caterpillar, and produce the characteristic wrigghng of the worm : 

 they appear in spermatozoa and in quite a large number of soft-bodied animals : they reappear in skeletal animals, 

 and are witnessed in the swimming of the fish and in the creeping of the serpent. They are likewise the chief 

 factors in the walking of quadrupeds and bipeds, and in the flying of insects, birds, and bats. 



The spiral structures and movements, as already stated, are fundamental — that is, they are not dependent on 

 fortuitous circumstances, or any form of stimulation or irritation. 



Examples of spirals (single and double) are found in large numbers in plants and in animals. Spiral formations 

 are symmetrical when two or four opposite spirals are employed. They are non-symmetrical . or lop-sided when 

 only one spiral is employed. Complementary spirals are by no means infrequent. 



The unaccountable thing is that crystalUne, dendritic, and spiral formations and movements occur both in 

 inorganic dead matter and in organic living matter. 



The subject of organic growth, development, and movement has many side-hghts thrown upon it by a con- 

 sideration of what may be regarded as inorganic growth, development, and movement — namely, the arborescent 

 frost pictures, as they appear on window-panes and pavements in winter, the branching dendrites formed in 

 minerals and metals, and similar dendritic displays made by lightning (revealed by instantaneous photography), 

 and when it strikes and scorches the human sldn. 



