254 DESIGN IN NATURE 



Looking at the subject of rhythm not as an isolated fact in physiology, but as one of a great series of move- 

 ments universal in their nature and extent, I am disposed to regard it as a primary endowment not confined to any 

 particular living substance, but inhering in all to a greater or less extent, and capable of manifesting itself in plant 

 and animal protoplasm, in rudimentary tissues, and in fully-developed muscular fibres, &c. 



Rhythmic movements, as explained, are not peculiar to the organic kingdom. They occur also in the inorganic 

 kingdom. The recurrence of day and night, the seasons, the rise and fall of the tides, &c., afford examples of 

 inorganic rhythms. The inorganic rhythms are, so to speak, the harbingers or parents of the organic ones. This 

 follows, because plants and animals derive all the materials which enter into their composition, and not a Httle of 

 the force which actuates them, from the inorganic kingdom. 



The rhythmic movements in plants and animals are essentially give-and-take movements, and, as such, are 

 fundamental ; that is, they are inseparable from life, and form a dominant factor of it ; they furnish the means by 

 which hfe is continued. They are spontaneous original movements which are co-extensive with life. They begin 

 with life and only terminate with death. They are not dependent on anything but themselves ; they are not the 

 result of irritation or any form of stimulation, external or internal. They are the media through which, and by 

 which, pabulum and power are supplied to hving organisms. 



Plants and animals could not exist as apart from rhythmic movements. Plants and animals take from and 

 return to the inorganic kingdom all the materials, gases, fluids, and solids which enter into and circulate within their 

 bodies. The give-and-take movements imply a double power in living structures — a power to take from and return 

 to — a power to appropriate, to circulate, to distribute nutritious juices, and a power to get rid of the effete or waste 

 products produced by vito-chemical and other changes. 



This double power of feeding and of transmitting the food through and out of the bodies of plants and animals 

 is a sine qud non of existence. It is the distinctive prerogative of life. Life without rhythmic movements, or their 

 equivalents, in one shape or other, would be impossible. Rhythmic movements are, in a sense, at once the cause 

 and the outcome of life, and they are manifested in the lowest as well as the highest plants and animals. They 

 are, moreover, within limits, the mainspring of life, and are not only inherent in the structures in which they occur, 

 but they are also, for the wisest of purposes, incontrollable by any power existing in plants and animals. It is not 

 possible to discontinue or stop the movements of the heart for more than a few seconds, or the chest for more 

 than a few minutes. These go on day and night, from the cradle to the grave. Rhythmic movements are the 

 outcome of the operation of vital laws which apply to all plants and animals. They are not dependent on the 

 presence even of cells, and they certainly occur in numberless cases where no trace of either muscles or nerves can 

 be detected. 



They, moreover, occur in substances and tissues which, in the normal condition, are in no sense irritable. 

 Neither are they naturally caused by, or in any way regulated by, external artificial stimuli. It is mere assump- 

 tion and abuse of language to say that rhythmic movements are the result either of irritation, excitation, or 

 stimulation. 



It is inconceivable that living substances and structures created for the express purpose of taking in food 

 (gaseous, hquid, and sohd), circulating the same, and ejecting the waste products, should be dependent for their 

 movements on inherent irritability or stimulation of any kind, especially external stimulation. Living structures 

 move deliberately and to given ends spontaneously, as apart from all kinds of collateral aids. They are prime 

 movers in the most emphatic sense. They set matter in motion, and are not themselves set in motion by matter, 

 unless under abnormal exceptional circumstances. 



Rhythmic movements are fundamental and essential to plants and animals. They cannot be separated from 

 them without serious impairment or loss of hfe. Anything which destroys the respiratory or circulatory movements 

 necessarily results in death : the continuance of rhythms is essential to the continuance of Hfe. 



In speaking of rhythms it is important to bear in mind that there are various kinds of rhythms, all more or 

 less necessary to the continuation of hfe, and therefore fundamental ; thus there is the rhythm of feeding, fasting 

 and defsecating ; the rhythm of circulating air and nutritive juices ; the rhythm of working and resting ■ the 

 rhythm of sleeping and waking ; the rhythm of hibernating and rousing at long intervals ; the rhythm of repro- 

 duction, &c. These several rhythms supply singly, or in the aggregate, the most incontestable evidences of life with 

 which we are acquainted. It is not too much to affirm that their temporary or permanent suspension in every 

 instance results in the dangerous impairment or death of the individual. All living things require food air fluids 

 semi-fluids, and sohds : they have to circulate their nutritious juices, to work and rest, to sleep and wake to re- 

 produce themselves, &c. The activities involved in obtaining food, circulating nutritious juices, reproduction &c 

 originate in the plant or animal : they express the potentiahties of the individual. If one or more fails death sooner 

 or later supervenes. 



