loo DESIGN IN NATURE 



A hasty generalisation would naturally lead to the conclusion that there is in the universe only one kind of 

 matter and only one kind of force. It might even be inferred that the living or organic kingdom is an outgrowth 

 or product of the inorganic kingdom, and that vital force is a mere variety and product of physical force. 



As, however, it has been satisfactorily proved that there is no such thing as spontaneous generation, a hne 

 of demarcation must be drawn as between dead and hving matter, and between physical and vital force. 



The question to be finally put is. How are the spiral structures and movements produced ? They are, so far 

 as I can make out, the result of independent growth and inherent endowment. The atoms and molecules of the 

 growing and moving parts are distributed in spirals and move in spiral directions. This they do under the mfluence 

 and guidance of a First Cause and of hfe. 



The spiral is a fundamental factor in structure and movement, behind which we cannot get. The spiral 

 formation of soft and hard parts, seeds and ova, muscles, bones, joints, shells, horns, fee, are all, in my opimon, 

 directly traceable to growth and original endowment ; and to the spiral distribution of the atoms and molecules 

 which constitute each particular form of growth and each particular kind of movement. 



The spiral distribution and movements of atoms and molecules, in the organic and inorganic kingdoms, are 

 not only under law and order, but they are under the same law and order. There is not one law for the spiral 

 inorganic, and another for the spiral organic formations and movements. 



The spiral distribution and movements of the atoms and molecules in the two kingdoms are never accidental 

 or haphazard. If this were so, the stabihty of the two kingdoms would suddenly cease and determine. 



§ i8. Growth in Straight Lines and in Spirals ; Longitudinal and Transverse Cleavage : Limbs, Fins, 

 Wings, &c. 



Growth and development, in order to meet the requirements of plants and animals, of necessity proceed in 

 two principal directions, namely, in straight lines and in spirals. Plants and animals modelled on these lines are 

 readily constructed, because they can grow or extend themselves into space without let or hindrance. They can 

 also move with perfect freedom, as their moving parts cannot, under any circumstances, over-reach or interlock. 



Many examples might be adduced to prove that inorganic and organic structures and movements very closely 

 resemble each other. 



The dendrites of minerals and metals, the frost pictures on window-panes and pavements in winter, the 

 lightning flash, &c., are amazingly Hke the arborescent forms seen in the branches and leaves of plants and trees, 

 the division and subdivision of blood-vessels and lymphatics, the branching of nerve cells, bronchial tubes, &c., to 

 say nothing of the body itself, which breaks up into extremities ; the extremities in turn dividing into digits, and 

 their expansions as seen in the fins and tails of fishes, the flippers of sea mammals, and the wings of insects, birds, 

 and bats. 



I am not aware that attention has ever been specially drawn to the manner in which the trunks of animals, 

 as it were, proUferate by a process of budding ; the Umbs, even in the highest animals, appearing as fleshy pro- 

 jections or buds in the developing embryo. The limbs, while growing, also bud at their free extremities into digits, 

 and the digits, in many cases, as stated, divide and split up to produce rays and membranes, as witness the 

 pectoral, ventral, and caudal fins of fishes, the nervures of the wings of insects, the flying membranes of the bat the 

 primary, secondary, and tertiary feathers of the wings of birds, &c. A very large percentage of all known animals 

 assume the dendritic form. The dendrites in animals may be symmetric or asymmetric, that is, they may display 

 perfect symmetry as in certain star-fishes, or asymmetry as in certain molluscs. The symmetrical animals bear a 

 recognisable resemblance to crystals and symmetric plants. The non-symmetric animals are comparatively few 

 in number, and may be regarded as exceptions to prove a rule. The dendrites in animals, in many instances take 

 the form of appendages — antennae, hairs, ciha, suckers, probosces, &c. ; they also, as explained, figure as arms 

 legs, wings, &c. The dendrites or outgrowths are functionally of great importance as sense-organs, as vehicles 

 for securing food, and as instruments of locomotion. Even pseudopodia take on the dendritic type and act in 

 straight hues. 



In the lower animals, we have examples of the dendritic arrangement in the Vorticella, Hydra Sertularia 

 Red Coral, Sea-pen, Actinia, Medusa, Comatula, Serpula, Rotifer, Sand-hopper, Beetle, Galeodes, Spiny Lobster Crab 

 Spider, the Leaf Insect, Cuttle-fish, &c. 



In the higher animals, the dendritic arrangements appear, partly as tegumentary appendages (scales hairs 

 feathers, horns, hoofs), and partly as travelling organs — fins, flippers, arms, legs, wings, &c. 



The serpent — a typical vertebrate animal — ^if the scales and ventral plates be excepted, is destitute of dendritic 

 outgrowths. In the Lepidosiren, four small tapering processes project from the under surface of the body and 



