THE Library of tiie flew York State Medical Association. LAWS AID MECHANICS OF CIRCULATION, WITH THE PRINCIPLE INVOLVED IN ANIMAL MOVEMENT. WM. H. TRIPLETT, M. E>., Member of the American Association for the Advancement of Science, etc., etc. Was nicht bewiesen ist Das braucht Man nicht zu glauben. NEW YORK : J. H. Vail & Co., 1885. COPYRIGHTED BT W. H TRIPLETT, M. D, 1885. ATKIN & PROUT, Printers, Nos. 16 and 18 Chambers Street, New York. DEDICATION. TO DR. ALBERT GUNTHER, The distinguished author and naturalist, British Museum, in recognition of his great services as an original investigator, and for his kindly heart, quick perception, and swift foot to lighten the labors of others, which rounds out and perfects character — a star in the galaxy — this work is reverently and affectionately dedicated by The Author. VI INTKODUCTION. anatomy, very creditable to the anatomists and histologists, but of no earthly use in the p .ysiologies, not being explained or elucidated as means to ends, which anatomy purely is, cocsisting of relative adjustments for special work, since it all relates to work, for which they are the relative adaptations. 3. The Harveian theory of the circulation, 1628, but no explanation of the portal circulation and for maintaining it in correspondence with the absorp- tive processes for producing a balance, otherwise impossible ; no explanation of the tissue-circulation or that connected with the cell-brood, the objective point for all the commerce, the cells being the workmen in the tissues ; a vaso-motor system of nerves, but not competent to explain the phenomena manifested through them ; no attempt to explain the numerous muscles and nerves (unknown to Harvey) to the vessels. 4. Numerous physiological experiments upon the nerves, muscles, blood- vessels, etc., by means of which deeply interesting phenomena are developed, but their relevancy to any fundamental circumstance in the organism, or con- nection with one another by reason of any principle in the mechanics, not shown ; illustrated by explanatory cuts showing the mode of procedure. Traube's Curves are beyond its reach ; so also the blood-pressure curves and the curves of intra-thora pressure. It offers no solution for the existence of " inhibitor" and " accelerator" nerves to the heart. It cannot explain the anatomy in the intestines, and why there should be a diaphragm in the mam- malia only. It cannot get fat, albumen, alcohol or any non-dializable sub- stance into the body, yet they are rapidly absorbed and the explanation easy. More or less remarks upon muscular irritability and contractility, but noth- ing of dualism in the muscles, without which musculation would be utterly impossible, etc., etc. The books large enough, too ; some of them a thousand pages, nearly, fine press. No grasp, no continuity of relations, all differing, but as far as possible from a philosophy. Each one following the train of facts he is most familiar with (compelled to it in the absence of a guiding principle), fitting the others into the text as best he can to make a book, at times appar- ently as though tumbled in at random till the book is big enough; vain strivings for order and method, however, discernible. The result nil. (I would like to make exceptions, but «annot ; though some of the books have remarka- ble excellence, and it wounds one to the heart to say aught against them.) With all this, wrong teaching most pernicious, doing irreparable harm to some minds, worse than night-blindness, for that would suffer the unfortunate to see by dayMght, but this by no light whatever ; but to any mind the work of wnlearning and starting afresh is most difficult, next to impossible, accomplished only by persistent and heroic effort. For example, respiration and circulation form a connected movement for supplying the cell- brood in the tissues and removing waste products ; but the physiologies treat them separately, basing circulation upon the heart, respiration upon the diaphragm. By what right is that done ? No right ; none. The birds, reptilia, and the rest of them, have no diaphragm ; neverthe- less, they respire ; besides, produce vocal resonance characteristic of them, showing that respiration is also under voluntary control, the same as in mam- malia. Air is got into the lungs by means of a pleural vacuum — speaking more correctly, a " negative pressure in the pleurae" — distending the organs in the first place by this means, then producing inspiration by contracting the INTRODUCTION. Vll diaphragm and intercostal muscles, then expiration by relaxing the muscles. It will not answer, and is not the method, as is fully proven in the text by the most incontrovertible evidence. Furthermore, the birds, etc., have no such explanation, passing them by ; but this cannot be done in physiology ; it all must be explained. And in the case of the worms, we have a complex circu- lation carried on where there is no heart, the vessels at the same time expand- ing and contracting regularly and rhythmically, possessing automatism the same as the heart, being also furnished with muscles and nerves for increasing force in them commensurate with the physiological requirements, You can- not begin at the end of animal life to write about circulation any more than respiration. In the embryo, but for the power to produce circulation inde- pendently of the heart, the heart itself could not be developed, while vascular development goes on simultaneously, the intestinal canal and other organs also, the heart-force coming in subsequently for increasing the action simply, the vessels growing pari passu with it. The theory breaks down and will not answer the physiological requirements ; is therefore incorrect. Then, again, the heart is used as a force-pump, which involves a suction with a driving force, but entirely ignoring the former by using contraction in the cardiac muscles simply ; whereas the organ would first have to be filled by diastole before one may speak of forcing the blood out of it by systole, thus producing a current through the organ, while expansion and contraction are correlated forces in Nature, therefore inseparable. It is needless to extend the matter, for physiology could not be more impotent ; nor can help come by scalpel and microscope : their work has been well done, the body taken down to the very cells themselves and polarizing lenses are set to them. In short, analysis may be said to be complete, but the key to animal structure and function not forthcoming, not to be forced by scalpel or microscope, or rather the latter, for the work is now in micro-organisms and cells. Nor can physiology remain where it is. The ground sinks, no firm foothold, every effort but sinking you deeper in the morass. A change must come, else there is no hope. The key to be found at all? Of course it should. The arrangements are visible and persistent, and for their full and complete interpretation requires only that the proper method be adopted. Set physiology in the opposite direction, or toward synthesis and reconstruc- tion, and you ivill find it, for this will take you to the organic law upon which the animal organism is based, and that is the key ; for it is as utterly impossi- ble to explain the mechanics in the absence of this principle as to explain any mechanism in the absence of the principle it involves, and the animal body is a mechanism. And though it differs from all others in that it is automatic, nevertheless this would not do away with the necessity for a principle upon which to base the mechanics, as must appear obvious. Life so mysrerious ! Granted. But life works in matter, and matter has laws eternal and inflexible regulating it. What law have you, then, as the basis of animal mechanics with which everything in the organism must have adjustment and every piece its place and relative value, in the very nature of things ? None. Then, it is manifest that you cannot explain the mechanism or write a physiology. In order to do this, the principle would have to be forth- coming first, and from that stand-point it is all made intelligible ; otherwise, is utterly inexplicable. But you cannot begin with animal or even floral life, for Vlll INTRODUCTION. the principle is not confined or pent up in them, extending into the very me- chanics for producing circulation in air and water, out of which living organ- isms are evolved. Commencing with this, thence through flora and fauna, noting the method for increasing it in the latter commensurate with the force expended in them ; when it will turn out that physiology is but natural philos- ophy, aDatomy means to ends, the functions resultant phenomena ; or, in other words, physiology is the descriptive anatomy and functions in the organs, the former being the special adaptations of means to ends in correspondence with the character and amount of work performed, since it all relates to work which must have its equivalent in force there and then ; the whole evolved out of circulation, while this in turn is regulated by law which is being inces- santly invoked in the measure of the requirements. Comprehensive it is, but easily understood. Finally, why should it be deemed an incredible circumstance to have a fun- damental principle in animal life, upon which the phenomena are based, seeing that everything in the visible universe is regulated by law, and that there is systematic and persistent arrangements in the structures ; otherwise inexplicable? Furthermore, method implies principle. And when similar arrangements in the structures and movements in the parts habitually occur in great classes of animals, we may rest assured that a common principle underlies it all ; and in order to interpret the phenomena it would be abso- lutely necessary to first make out the mechanical principle that applies. And since the whole relates to work, there should be no difficulty in determining this circumstance. Such, in brief, is the course adopted in this work, commencing with the laws and mechanics of circulation as applied to the pumping movements in lungs, heart and vessels, which undoubtedly relate to rhythmical changes in pressure for increasing circulation commensurate with the force expended in the organism, seeing also that these movements are in correspondence with the activities, rising and falling with the swell in the activities, the whole forming a connected movement in the very nature of things. And while there is automatism in the organs and the heart continues to beat for a time after res- piration is suspended, it is no infraction of this principle, for in no other way could a balance be maintained in the organism, the heart and vessels being simply a carrier between the cell-brood and lungs, while respiration is the great pumping action for compelling the commerce in the organism. In short, that respiration answers to the pendulum in the clockwork, while the heart and vessels are set to this as the minute hand to the hour hand ; so that it all works together harmoniously and in perfect concord, to the end that a stream of commerce may be maintained between the cell-brood and environ- ment, from which all the supplies are obtained, and into which in due time waste products are returned for redistribution, the eternal order of tilings. Beginning, then, with the principle for producing circulation in air and water, and for pulling the molecules into position and locking them in the structures, or similar to what takes place in crystal structure (which is ap- proximated in plants and bones, while in the soft tissues there is provision for freer molecular action) you come into immediate contact with that all-absorb- ing question, What is Life ? I cannot make out aught else than a form of force — wonderful metamorphoses in force ; using present terminology, Life is an INTRODUCTION". IX "eddy" in force. With force, itself , there we stop. The ultima Thule ! But this we know of a surety, that force is controlled by laws eternal and inflex- ible, while matter manifests them, and is energized by force. Nor need we fear to follow to their logical conclusions the fundamental principles in Nature. A stream cannot rise higher than its source ; and man intelligent, it follows there must necessarily be intelligence in Nature — all -pervading intelligence ; further I cannot say ; das ist genug. In conclusion : This work, as the name implies — Life : Its Laws and Mechanics — would include all vital phenomena, but as circulation underlies it all (fur- nishing the materials for elaborating structure and evolving force, but involv- ing the principle concerned in animal movement, in order to increase circula- tion), this would naturally have precedence, the rest following in regular order, to be published as a serial, beginning with "Gravitation and Devel- opment," gravitation being pivotal, so to speak, in development, showing the intimate relations it sustains to the latter to the very minutia in tissue- structure, the organs of circulation with those of respiration, locomotion, etc., but most manifest in the frame- work of support to the soft tissues or bony skeleton ; a very notable circumstance being the mode of conserving the central nervous system by supporting it upon a ' ' water-bed" formed of the cerebro-spinal fluid and the fibrous leaflets in the "falx cerebri" and " tentorium cerebelli," with the nerves running into them for regu- lating tension, so as to obviate concussion in locomotion, leaping, etc. ; the principle involving the articulations themselves, for the brain must be protected against jar. But all the organs exhibit adjustments with gravi- tation. The great development of the vascu]ar system in land animals, the numbers of the muscles and nerves in the heait and vessels, have similar explanation, the fluids tending constantly to the earth. In fine, every movement in the mass and molecules must necessarily involve a struggle with this force, as must appear obvious. Nay, to the very mode of rising up and lying down, the animals doing it differently by reason of the special adjustments that obtain in the viscera, the ruminants elevating the hinder par: s first, then bringing up the fore parts, reversing the action when lying down ; whereas, the other animals elevate the fore parts first, then bringing up the hinder parts, reversing the action when lying down. And that it is not awkwardness in the ruminant which causes it to take the course it does, is proven by the fact that the fleet deer and nimble antelope go through the same movements. Finally, strange and fanciful as it may seem, nevertheless, the relative stages in development in the anthropoid apes are readily determined by it, beyond the shadow of a doubt, and gorilla is closest to man of any existing species, which is not a figment of the mind born of a lively imagination, but a sober fact wrought in the bony skeletons of the ani- mals, very plain and easily to be seen. We would not anticipate, however, but let the present work serve as earnest of that engagement. Nature works by laws immutable, and everything is determined bylaw, while order and method are made inevitable. And the very fact itself that so much is explained within the compass of the present work, is conclusive proof that correct Lines have been adopted. Digitized by the Internet Archive in 2010 with funding from Open Knowledge Commons (for the Medical Heritage Library project) http://www.archive.org/details/lawsmechanicsofcOOtrip Ubrarj of iiko TSTewTork State Medical Association. CONTENTS. CHAPTER I. MECHANICS FOR PRODUCING CIRCULATION IN AIR AND WATER, AND FOR CONNECTING THEM WITH CIRCULATION IN LIVING ORGANISMS. The Fundamental Fact at the Basis of Living Organisms— Living Organisms Evolved from Substances Contained in Air and Water— Mode of Suspending Atmospheric Matter in Space, and the Principle for Producing Movement among the Mole- cules—Experiments of Dufay and Faraday with Electricity and Magnetism— Action of Gravitation Overcome by Electrical Force— Transformations of Heat into Elec- trical Force for Energizing the Polar Forces among the Molecules, the Fundamental Principle for Producing Circulation in Air and "Water— The Prodigious Force which is Involved for Producing Circulation in the Atmosphere and in "Water— The Mechanics Connected Through and Through by Means of Electrical Force- Electrical Phenomena in Storms— Mode of Effecting Changes in Pressure for Increasing Circulation in the Atmosphere— The Action in "Water— Principle in Diffusion, Osmose, Capillarity— Organic Connection Subsisting between Circula- tion in Air and Water and in the Living Organism ... - Page 1 CHAPTER II. THE FLORAL CIRCULATION. Principle in the Floral Circulation — Action of the Polar Forces and the Mode of Increas- ing it — Physiological Experiment Demonstrating the Energy of the Polar Forces in Flora — Circulation in Flora Comparatively Slow — Deduction to be Drawn There- from— Explanation for the Rapidity of Circulation in Fauna and the Amount of Food Consumed by Them .----------S3 CHAPTER III. THE ANIMAL CIRCULATION. Principle in the Animal Circulation — Adjustment with Pressure and the Power of Pro- ducing Rapid Rhythmical Changes in Pressure, the Law in the Animal Circulation — The Movements in Respiration : Heart, Arteries, etc., Pumping- Aetions for Increasing Circulation, the Whole Forming a Connected Movement for Increasing Circulation between the Cell-Brood and Environment, whence the Nutri- tive and Force-Producing Elements are Derived, and into which the Waste Products 1 CONTENTS. are Returned — Explanation for the Correlation of the Vaso-Motor and Voluntary- Motor Centres with the Respiratory Centre — Mechanics in Inspiration and Expira- tion— Two Respiratory Movements Performing at the Same Time ; One in the Lungs, the Other in the Tissues — Physiological Experiments, Showing that Pressure is the Fundamental Circumstance in the Animal Organism with which Everything has Adjustment, and that the Actions in the Lungs% Heart, Vessels and Hollow Viscera Relate to Changes in Pressure for Compelling Movement in the->Contents : t. e., for Increasing Circulation— Otherwise are Meaningless 29 CHAPTER IV. RESPIRATION IN DIFFERENT STAGES IN DEVELOPMENT. Import of Amoebae Movement — The Alternate Extension and Retraction of the Branched Processes, a Pumping Action for Increasing Circulation — Why Locomotion Should Increase Circulation Correspondingly — The Pumping Movements Analogous with Respiration — The Action in Vacuoles and the Radiating Canals, an Early Indication of the Mechanical Principle in the Heart ancLArteries, the Latter Expanding as the Former is Contracting and Vice Versa — The Action in Gastrula — Necessity for Co- ordinating the Mucous with the Skin-Surface, in Order to Produce Afflux and Efflux of the Fluids in the Body-Interior — This Circumstance Further Dlustrated in the "Worms for Producing the Undulations which Course along the Body During Imbibition— The Principle Applied to Respiration and the Action Taking Place in the Lungs — Illustrated in the Prog, in which it is Demonstrated Experimentally that the Lungs Expand and Contract Regularly and Rhythmically Synchronous with the Action Taking Place in the Muscular Envelope or Containing Walls, in Order to Produce Afflux and Efflux of Air and Blood in these Organs for Respira- tory Purposes ; Otherwise Impossible — The Manner the Parts are Coordinated — Dependence of the Portal Circulation upon Respiration — the Same Principle in Mechanics for Every Stage in Development — The Action in Birds — The Special Adjustments in the Viscera — Portal Circulation in - 4G CHAPTER V. RESPIRATION IN MAMMALIA. Respiration in the Mammalia Fundamentally the Same as in Birds and Reptiles, the Lungs and the Muscles in the Abdomen Expanding and Contracting Simultaneously — Office of the Diaphragm and the Ocassion for it — The Action in the Diaphragm Alternating with the Muscles in the Abdomen, the One Contracting as the Other is Expanding, and Vice Versa — The Action the Diaphragm Exerts upon the Ribs, Bending and Flaring them Open upon the Sides During Inspiration, and Vice Versa During Expiration — Mode of Coordination, Inclusive of the Lungs, the Whole Moving in Perfect Con- cert— Circumstances in the Vital Phenomena, Anatonncal and Physiological, which Make it Absolutely Certain that the Lungs Expand and Contract Regularly and Rhythmically Synchronous with the Actions in the Diaphragm and Containing Walls— Physiological Experiments Proving this Circumstance — The Action in the Tracheal System — Mode of Maintaining Cleanliness in the Alveoli and Air-Pas- sages— Significance of a Cough — The Action of the Trachea in Vocalization — Ex- planation for the Devious Course of the Recurrent Laryngeal Nerves, which First Descend into the Chest to Connect with the Lungs Before Proceeding to the Larynx and Vocal Cords, A scending thence Upon the Trachea for this Purpose, no matter how Long the Neck may be : e. g., the Giraffe 83 CONTENTS. Xlll CHAPTER VI. THE MECHANICS FOR CIRCULATING BLOOD IN THE LUNGS, AND THE ACTION OF THE HEART AND ARTERIAL SYSTEM IN CONNECTION THEREWITH. Mechanics for Circulating Blood in the Alveoli — Anatomical Dispositions in the Walls of the Alveoli for Effecting it, or for Compelling Circulation of Blood in the Plexuses to be in Correspondence with the Circulation of Air in the Alveoli — Extent of the- Alveolar Plexuses and the Manner they are Affected by Inspiration and Expiration — Functions of Residual-Air in this Connection — An Elastic Cushion for Transmit- ting the For^e in the Lungs and the Muscular Envelope upon the Plexuses for Com- pelling the Blood to be in Correspondence with the Circulation of Air in the Alveolar- Chambers — Manner of Maintaining a Balance in the Dual Circulations in the Alveoli — Relations which the Heart Sustains to the Pulmonic Circulation — Mechanical Prin- ciple in the Heart Itself — Anatomical Dispositions in the Right Side Adjustments. with the Functions in the Lungs— Ditto, Left Side — Nerves for Effecting Coordina- tion with the Lungs — Action in the Arterial System Synchronous with Respiration —Nerves for Effecting it — Physiological Problem Connected with the Curves in Blood-Pressure Tracings and the Curves in Intra-thoracic Pressure— Traube's Curves — Physiological Experiments Proving the Existence of Rhythmical Expan- sions and Contractions in the Arterial System Synchronous with the Actions in the Heart and Lungs ------------- ] 21 CHAPTER VII. AUTOMATISM IN THE VESSELS, AS WELL AS IN THE HEART. Principle in Cardo-Arterial Movement — The Arterial System Expands as the Heart Contracts, and Vice Versa — Mode of Proving this Action in the Vessels — Evidence in Arterial Tracings — Arterial Tracings Contrasted with the Artificial Tracings, Produced by the Apparatus of Marey, Showing Essential Points of Difference, and Proving Incontrovertibly Automatism in the Vessels— The Variations in Blood- Pressure Tracings Corroborative of this Action in the Vessels, Confirming the De- ductions from Arterial Tracings — All the Elements in Arterial Tracings and the Tracings which are produced by Variations in Blood-Pressure Harmonize — The Facts in Development Confirmatory of Automatism in the Vessels — Regular Rhyth- mical Expansions and Contractions Taking Place in the Vessels of the "Worms in the Entire Absence of a Heart for Producing Them, the Vessels Expanding and Con- tracting Themselves— The Pulsations in the Umbilical Cord not Synchronous with the Action in the Fcetal or Maternal Heart ; Moreover, Pulsates even after Connec- tion is severed — The Pulsations in the Ears of a Rabbit and in the Wings of a Bat not Synchronous with the Action in the Heart, Showing Independent Action in the Vessels — The Special Anatomy in the Vessels Fundamentally the Same as in the Heart — Progressive Increase of the Muscles in the Arterial System from the Heart to the Tissue-Territories — Function of the Strong Elastic Coat — How High Pressure is Produced, and the Occasion for it — How Reflux in the Capillaries is Obviated — Mode of Increasing and Diminishing the Local Actions, and for Coordinating the Vessels with Respiration and the Action in the Heart. ----- 138. CHAPTER VIII. RESPIRATION IN THE TISSUES AND THE ACTION OF THE CAPILLA- RIES IN CONNECTION THEREWITH. Two Respiratory Movements Going on at the Same Time in the Body, One in the Lungs, XIV CONTENTS. the Other in the Tissues — The Force for Producing the Movements Propagated from the Medulla Oblongata and Respiratory Centre — The Composite Character in Arterial Tracings Readily Explained — Rhythmical Expansions and Contractions in the Tissues Synchronous with the Actions in the Lungs, Heart, Arteries and Capillaries — The Waves Superposed upon One Another in the Order Named, or the Cardo- Arterial upon the Respiratory, and the Capillary or Dicrotic Waves upon the Cardo- Arterial — Capillary Action the Source of Dicrotism — Mode of Demonstrating this Circumstance — The Action in the Capillaries Producing a Current Into and Out of the Tissue-Interstices — Relations of the Cell-Brood to this Circulation — Nervous Apparatus for Connecting Them with the Capillaries and Central Nerv- ous System for Increasing and Diminishing the Local Circulation, with the Exigencies in the Functions — Mechanics in Blushing — Explanation for Arrest of Arterial Pulsations upon the Distal Side in Aneurisms — Action in the Venous System — Functions of the Muscles and Nerves in Veins — The Relations they Sus- tain to Respiration — Explanation for the Great Volume of Venous Blood and the Slowness in this Circulation — Also for the Motion in the Brain Synchronous with Respiration. ------ 159 CHAPTER IX. THE PORTAL CIRCULATION AND THE MECHANICS IN THE ABDOMEN. The Intestines of Mammalia Filled and Distended with Air for Increasing the Digestive and Absorptive Processes, Serving the Purpose of an Elastic Cushion for Trans- mitting the Force in the Gut upon the Food for the Purpose — The Action not Un- like that which Obtains in a Churn — Necessity for a Diaphragm — Existence of High . Pressure in the General Cavity of the Abdomen Produced by the Air in the Intes- tines for Increasing the Portal Circulation so as to Maintain this in Correspondence with the Absorptive Processes — Principle of Coordination Applied to the Stomach and Walls of the Abdomen for Effecting Ingestion and Office of the Pneumogastric and Phrenic Nerves in Connection Therewith — Why the Animal Rises when Eating and Drinking — Why Respiration is Suspended During Deglutition or After the Ali- ment has Passed the Glottis, and the Danger of Intrusion in the Air-Passages is Over — The Action in the Stomach and the Physiological Anatomy in the Organ — The Role in the Air-Cushion in Connection Therewith — Similar Survey of the Intestines — The Rapid Absorption of Fat, Alcohol and Other Non-Dializable Substances Easily Explained — The Fine Adjustments in the Muscularis Mucosae and the Mode of Coordinating Them with the Muscles in the Walls for Making Absorption Very Effective — No Difficulty in Absorption 185 CHAPTER X . RESPIRATION AND THE PORTAL CIRCULATION. Circulation in the Liver Dependent upon Respiration— Mechanics in the Diaphragm and Walls of the Abdomen Respecting it — The Mesentery a Soft, Elastic Cushion for Effecting Gentle Compression of the Liver-Substance, under the Action in the Dia- phragm and Walls of the Abdomen during Inspiration for Increasing its Circulation — Mode of Demonstrating this Circumstance — Effect upon the Portal Vessels and Lower Cava-System — Absence of Valves in the Veins within the Abdomen, save in the Pelvic Viscera Only — Explanation for the Latter Circumstance — Physiological Anatomy of the Liver with Reference to Circulation— Why the Hepatic Veins are Incorporated with the Liver-Substance — Relations of the Portal System to the Hepatic Veins— Why Rhythmical Compression of the Liver-Substance during Res- CONTENTS. XV piration should Increase Circulation in the Inter- and Intra-Lobular Vessels Oorre- pondingly — Automatic Action in the Portal Vessels Synchronous with Respiration for Further Increasing it — Mechanics for Circulating Bile — The Action in the Gall- Bladder and Bile-Ducts — The Action in the Duodenum, in Connection with the Biliary and Pancreatic Secretions — Adjustments in the Viscera Necessitated by the Action in the Diaphragm — Mechanics Connected with the Openings in the Dia- phragm— (Esophagus Constricted during Inspiration, while the Vena-Cava Lumen is thrown Widely Open; as also the Aortic — Elongation and Contraction of (Esophagus with Inspiration and Expiration — Ditto Venae Cava? — Ditto Portal Vessels and Renal Veins — Similarity in the Anatomical Dispositions of the Muscles in these Organs -------___.__ ggQ CHAPTER XI. AUTOMATISM IN THE LYMPHATICS AND THE MECHANICS FOR CIRCULATING LYMPH The Lymphatic System Intercalated between the Arterial and Venous Systems, Arising in the Tissues and Debouching in the Veins at the Root of the Neck — The Dual Functions in these Organs Concerned in Drainage and Haamatosis — The Vessels Connecting with Respiratory Movement in the Tissues, Expanding and Contracting with the Blood-Capillaries by Means of the Nervous Connections Subsisting between Them — The Action in the Larger Vessels and Gland-Structures — Muscles and Nerves to the Organs for Producing the Actions — The Action in the Lacteal System and the Manner in which it is Affected by the Action in the Gut for Compelling Rapid Movement of the Fluids in the Vessels— The Relations which this Sustains to Inspiration and the Action in the Venous System — Physiological Experiments Proving that Inspiration Pumps the Lymph into the Venous System Simultaneously with the Portal and Hepatic Blood— Proof of Automatism in the Vessels -----____._ .. 347 CHAPTER XII. NERVES TO THE VISCERA IN THE ABDOMEN, AND MODE OF CONNECT- ING THEM WITH THE CEREBROSPINAL AXIS. The Double Ganglionic Dorsal Chain in Vertebrates, the Analogue of the Double Ganglionic Chain in the "Worms— Nerves of Meissner— Nerves of Auerbach— Mode of Connecting them with the Solar Plexus and Central Nervous System— Relations of the Nerves of Meissner and Auerbach with the Intestinal Mucous Membrane and Epithelium— Mode of Controlling the Blood-Supply from the Aorta-Trunk by Means of the Cceliac Axis, Superior and Inferior Mesenteric Arteries and their Branches, so that Every Organ and Fractional Portion of the Same can Regulate their own Sup- plies in the Measure of the Functional Activities— Connection of the Pneumogastric Nerves with the Solar Plexus— Mode of Connecting the Solar Plexus and Spinal Ganglia with the Dorsal Nerves and Spinal Medulla, the Nerves of the Ganglionic Chain running up Both Roots of the Spinal Nerves to Reach the Spinal Medulla— Every Nervous Ganglion a Centre of Nervous Force, Possessing both Sets of Fibres, or Dilator and Contractor Nerves— The Manner Reflex Action is Produced in the Spinal Cord and Medulla Oblongata through Sensory Impressions in the Mucous Membrane and Cutaneous Surface, for Expanding and Contracting the Vessels and Maintaining: a Balance in the Circulation — Relative Amount of Nervous Force sent to the Viscera through the Pneumogastric and Splanchnic Nerves, Dlus- trated by a Case of Fracture of the Fourth and Fifth Cervical Vertebrae, Producing XVlll CONTENTS. CHAPTER XVIII. DUALISM IX MUSCLES AXD NERVOUS FORCE. Nature of Vital Force — Principle in Expansion and Contraction — Molecular Changes in the Cell-Contents Involved in both Movements ; Illustrated by the Action in Pro- toplasm and in Muscle Cells during Contraction, as Seen in the Field of the Polar- izing Microscope — Dualism in Nervous Force Essential to the Production of both Movements — Extraordinary Hardness Produced in the Muscles by Nervous Force — Explanation Therefor— Hardness a Measure of Work— Mode of Demonstrating This Circumstance — An Easy Method of Proving Dualism in Muscles, and by Implication Nervous Force— Lessons Taught by the Phenomena in the Leech— Ditto, Tongue of the Frog— Ditto, Tortoise ; the Action in the Head, Neck and Tail Demonstrating Dualism in Muscles and Nervous Force— Ditto, Conchifera, for Opening and Clos- ing the Valves ; Together with Physiological Experiment Demonstrating the Cir- cumstance— Ditto, Inferior Maxilla in the Dog, showing the Masseter and Tem- poralis Muscles are Operated in the Same Way, the Mouth being Opened and Closed by Means of Expansion and Contraction in these Muscles — Physiological Experiment upon the Nerves to the Ciliary Ganglion Proving Dualism in Nervous Force upon the Nerves — The Circumstance Applied to the Oral Muscles and the Action in all the Sphincters, all of Them in Common Possessing Circular and Radiating Muscles, the Same as the Iris— Action in Erectile Tissue Readily Ex- plained ; Elucidated by the Action in the Tongue of the Chameleon, Penis, etc. — The Special R61e in Nerves with Respect to Nervous Currents, Nervous Centres, Separators and Delimitators of Electrical Fluids Generated in the Tissues and Carried to the Centres for this Purpose — Reasons Therefor ... - 444 Library of tke New York State Medical Association. CHAPTER I. MECHANICS FOE PRODUCING CIRCULATION IN AIR AND WATER, AND FOR CONNECTING THEM WITH CIRCULATION IN LIVING ORGANISMS. The Fundamental Fact at the Basis of Living Organisms — Living Organisms Evolved from Substances Contained in Air and Water — Mode of Suspending Atmospheric Matter in Space, and the Principle for Producing Movement Among the Mole- cules— Experiments of Dufay and Faraday with Electricity and Magnetism — Action of Gravitation Overcome by Electrical Force — Transformations of Heat into Elec- trical Force for Energizing the Polar Forces Among the Molecules, the Fundamental Principle for Producing Circulation in Air and Water — The Prodigious Force which is Involved for Producing Circulation in the Atmosphere and in Water — The Mechanics Connected Through and Through by Means of Electrical Force — Electrical Phenomena in Storms — Mode of Effecting Changes in Pressure for Increasing Circulation in the Atmosphere — The Action in Water — Principle in Diffusion, Osmose Capillarity — Organic Connection Subsisting Between Circula- tion in Air and Water and in the Living Organism. Logically as well as scientifically, the fundamental fact at the basis of living organisms is the one of circulation, since it is by means of this the materials are furnished for elabo- rating structure and evolving force ; otherwise, neither the building itself could have construction, nor could the special vital phenomena be produced, since they are all evolved out of circulation from substances which are brought into the organism by this means, and which, of course, would include the psychical with the rest, being a variety simply, and as much dependent upon circulation as any of the others. In other words, should circulation stop, it all stops, and which is a matter so obvious that it needs no argumentation. In the second place, the nutritive and force-producing ele- ments are contained in air and water, notably oxygen and hydrogen, carbon and nitrogen, together with the alkaline earths and minerals. Moreover, are incessantly in motion in every conceivable direction, both the fluids themselves and the molecular and atomic constituents, so that it may be truly 2 ATMOSPHF.KIC CONSTITUTION. said they are never still save when locked in crystal and living structure ; and even here a degree of movement takes place, but more in the latter than in the former, and more in animal than in vegetal structure, while the freest motion is that which obtains in the conditions of air and water in which the molecules and atoms have the widest action, the atoms with the molecules. Notwithstanding, it is all organized, the air and water with floral and animal life, a definite molecular constitu- tion being maintained throughout. Thus, in the case of the atmosphere the relative proportion of the constituent gases remains the same, or about 77 parts of nitrogen, 21 of oxy- gen, and 2 parts made up of watery vapor, carbonic acid, ammonia, etc., in the 100. This, notwithstanding the enor- mous sources of disturbance in the countless flora and fauna, inclusive of the chemical reactions taking place in the earth itself, together with the combustions and chemical reactions effected through the agency of man, which are constantly absorbing and giving out the gases in prodigious amount, and which proves beyond the shadow of a doubt the action of an all-pervading force for effecting it, or for compelling the molecules into their relative positions in the atmospheric envelope. In short, that a principle obtains among the indi- vidual atoms and molecules for producing movement in them, and acting in such wise as to compel definite arrangements among them, to the end that the atmosphere and living struc- ture may be organized and a balance maintained throughout, otherwise is inexplicable. In the case of water, we find that here also the same princi- ple applies for producing movement in the atoms and molecules for compelling absorption and solution of the salts, so as to effect the chemical and physical constitution that obtains in this fluid, and in order to maintain a balance which tends inces- santly to be disturbed, at the same time, producing perpetual motion throughout in the mass and in the molecules the same as in the air ; using an expressive term, the whole seeming, as it were, "alive." The ultimate fact in the deep mystery is the one of motion itself, the manner it is produced, with the principle it involves; for life is evolved by means of it, and may be characterized as a metamorphosis of force ; seeing also FORCE. 3 that when life terminates the whole breaks up into its atomic and molecular elements and goes back whence it came, and there is nothing left. While to this, again, must be added the deeply suggestive fact that organic unity implies similarity in force. So that continuity in force, which undoubtedly exists, would imply that vital force is but a variety of the force which produces molecular action in air and water, an organic connection sub- sisting between them for producing the currents in and out the organism in the measure of the requirements, otherwise im- possible ; at once indicating the nature of the force for effect- ing the nutritive processes, together with the other phe- nomena, the whole being electrical and polar. Thus, in the flora, in which life has simplest expression, the nutritive and force-producing elements are pulled into the organism by the action of the. polar forces upon the principle which obtains in a magnet, while for expelling waste products the action is simply reversed. In the transit the component atoms and molecules are pulled into position and locked in the struc- tures by the action of the polar forces upon the same principle precisely which obtains in crystal structure, only the action is more complex ; while the waste products are borne out for redistribution by action of the same forces, distribution with redistribution being the eternal order. In animal life there is still greater complexity, which is involved in producing the characteristic phenomena, notably the multitudinous actions taking place in them. At the same time, a special arrangement obtains for increasing circulation commensurate with this cir- cumstance, and for producing a balance, which the scheme calls for ; for everything is evolved out of circulation from sub- stances brought into the organism by this means, as before remarked. Finally, since all this motion involves mechanical work, it would seem both reasonable and natural that the principle underlying it should be susceptible of formulation and distinct mental presentation A force in such universal and constant action should surely be detectable, if only we go about it in the proper way. In the first place, let us take up the action in the atmosphere. C FORCE. This matter settled, and there will be no difficulty in account- ing for circulation in living organisms, which is but an exten- sion of the same principle in mechanics, as we shall very plainly demonstrate in the succeeding pages, the matter being one of variety simply. Concerning the Force for Effecting the Suspension of Atmos- pheric Matter in Space and for Producing incessant Motion in it against the Force of Gravitation : Commencing at the bottom, then, so to speak, and dealing only with the forces in Nature, the first question which presents itself to the thoughtful student concerns the mechanics for effecting the suspension of atmospheric matter in space and the pro- duction of incessant motion in it against the force of gram tation, which tends to pull it to the earth in a compact mass. In short, why should there be an atmosphere at all upon the globe ? and how is motion produced in it % — facts which are certainly needing explanation. The atmospheric molecules do not touch each other, as in the case of a solid ; on the contrary, they are far removed from each other, so that even at the earth's surface, where density is greatest, the atmosphere would require to be compressed fully 700 times to reduce it to the density of a liquid, while the molecules recede farther and farther from each other with the distance from the earth till the outermost limits are reached (Fig. 1). In point of fact, the molecules are relatively as far apart in proportion to size as the very stellar masses them- selves : furthermore, when forcibly compressed, react with equal force, at once springing back to the original distances the moment pressure is relieved, proving thereby inter-molecu- lar action from the presence of a force radiating from molecule to molecule, otherwise is inexplicable. Now, then, this fact being indisputable, the question which naturally presents concerns the nature of this force. What is it ? This must be established before progress can be made in the mechanics of circulation, forming, as it were, the basis of the mechanics, and by means of which the nutritive and force-producing elements are set in motion for elaborating structure and ATMOSPHEEIC MAI TEE. evolving force, the whole connecting through and through, the matter necessarily involving continuity in force in order to effect these results. • • • _ o Jo ° o 0 o o ^ °a9 ° 0 o o° o"j ° 1 ° ° o o o 0 O o O O q >o ° o ° o ° O o , © ° °< o o o o o o o o o _o o 0 o ° ° o' o o \j _ O O q o o ,0o°00oVo0oo00°o0°oOo°oO°Ooo:jo-0 °o°°oro0o0=V0Oo°co^o„o0°,oo0o0 0--0-«--V.°-,0o 000 ° °o"o0°0o0o0!;o ° °oo" Fig. 1. — An Ideal Section of the Atmosphere, showing the Suspension of this Matter in Space against the Force of Gravitation, a, a, Molecules of Nitrogen, Oxygen, Car- bonic Acid, etc. ; b, b. Aqueous Molecules. In this we are materially assisted by the celebrated experi- ment of Dufay for proving the existence of two electricities, 6 POLAll FOKCES. or positive and negative, which is plain enough. For ex- ample, he discovered, by means of a glass rod excited by rapid friction, that a gold or silver leaf, when liberated near it, is both attracted and repelled by it. At first, is powerfully attracted, dashing impetuously toward it, and, suddenly stopping, dashes in the opposite direction, when it again stops suddenly, remaining stationary from two to three inches from the rod, suspended in the air (Fig. 2). And if one so mind, he may chase it round and round the room for hours without permitting it to fall to the ground. The knob of a charged Leyden jar, or the conductor of an electrical machine in action, has the same effect ; and which proves the action is due to electricity. The use Dufay made of this experi- ment was to demonstrate the existence of two electricities, or positive and negative, whereby substances are attracted and repelled from each other, according to whether they are charged with opposite or the same kind of electricity. The attraction in the first instance was due to opposite elec- tricities, while the subsequent repulsion was due to the passing over of some of the electricity from the more highly electrified glass to the metallic leaflet, whereby their properties were assimilated ; hence this repulsion. The point where it remains stationary represents, of course, equilibrium in the polar forces. But, then, this describes only a part of the phenomena embraced in this experiment, which admits of much wider application than proving the existence of two electricities simply ; notably, the mechanical worJc which is involved in sustaining matter in space, and producing movement in it against the force of gravitation, which tends to pull it to the earth. Thus two great and important elements in this elec- trical experiment are entirely overlooked: 1. The fact that matter may be held up and sustained in space by electrical force simply. 2. That motion can be produced in it by a change in polarity effected through electrical induction — facts which are incontrovertible. Now, then, proceeding cautiously, feeling the ground, as it were, to make sure of its firmness : Is there any other force in Nature for thus suspending matter in space and producing movement in it against the force of gravitation, save electricity ELECTRICAL FORCE. 7 and the interaction of the polar forces which electricity serves to intensify \ Not that we know of. No, not any force what- ever may be spoken of in this connection, save electricity alone. And making deduction from this upon the mechanics in the atmosphere, it follows that electricity is the force we are in search of for effecting the suspension of atmospheric matter in space, and for producing movement in it, no other force applying for the purpose. This fact conceded, the next question concerns the source of electrical supply, together with the manner of its action, which is also obvious. Thus the sun functions as the source of electrical Fig. 2. — Showing Matter Suspended in Space by interaction of the Polar Forces, intensified by electrical induction. supply, by means of which the Leyden jar in the earth itself is kept constantly charged with electricity, whence it radiates through the atmosphere by the principle of electrical induc- tion for effecting suspension of this matter in space (Fig. 1), and for producing movement in it. In other words, heat, impinging against the earth, undergoes transformation into electrical force, which is the motor in the mechanics. That heat per se is not the motor, is at once made obvious by the fact that rarefaction in the atmosphere increases with the cold and the distance from the earth (Fig. 1), being 8 SOLAR FORCE. greatest at the outermost limits in the atmosphere where cold is enormous, whereas the very opposite should obtain by the laws of radiation, the surface being the first chilled, producing con- densation— an increase in density. In short, producing a com- pact mass. In lieu of this, however, the inter-molecular dis- tances are vastly increased, showing conclusively that heat is not the force for effecting this action. In point of fact, the atmosphere is nearly transparent to heat, and but for the aqueous vapor suspended in it, nearly the whole of the solar beam would reach the earth. And allowing for this circum- stance, Professor Tyndall estimates the invisible rays or the heat portion of the solar spectrum to approximate that in the spectrum of electric light, or nearly eight times the visible rays (Fig. 3), which will give some idea of the enormous role which heat performs in terrestrial mechanics. Furthermore, it is illu- sory to imagine that all this heat radiates into space, since a prodigious amount undergoes transformation into mechanical work and electricity, which is the dynamic force for produc- ing molecular action by increasing the polar forces in the molecules, and which applies to living as well as to non-living matter. Perhaps we might illustrate this circumstance better by drawing from the early experiences in animal temperature. For example, after Lavoisier had established the fact that animal temperature is the result of oxidation, upon the same principle precisely as obtains in a grate and the burning of coal, physicists made great efforts to determine the equality between the theoretical heat as indicated by the amount of carbonic acid discharged and the quantity of heat furnished \yf the animal, and which, of course, was illusory, for it made no allowance for the large amount which disappears by con- versions into mechanical work and electricity for producing the multitudinous actions taking place in them. And making the same deduction for the solar beam and the mechanics for circulating air and water, inclusive of the actions in living organisms, it at once becomes obvious that a vast amount of heat must necessarily disappear in the transformations. Then, again, one-half only of the earth presents to the sun at a given time, and as electrical force may make the circuit of the earth in one-tenth of a second (as the solar beam HEAT. 9 travels nearly 12,000,000 miles in a minute), it follows that this should call for corresponding increase in the transformations of heat for energizing the actions in the dark portions of the earth, and which wonld reduce in proportion the radiation into space. Hence, we must conclude that the greater pro- 10 THE FORCE IX AERIAL MECHANICS. portion of the heat in the solar beam is utilized in the terres- trial mechanics, since every movement calls for corresponding expenditure of force. Finally, these conversions of heat into mechanical work and electricity are facts which are uni- versally conceded in science, being fully established and incon- trovertible. Impinging against the earth, then, this invisible portion of the solar beam rebounds as electrical force through the atmosphere, driving and scattering the molecules in every possible direction. In fine, the impact of the solar beam against the earth fractures and scatters the atmospheric en- velope in accordance with well-known physical laws, or as a hammer does a piece of glass, the force radiating from the point of impact and driving the outermost fragments further- est apart. Hence, rarefaction in the atmosphere increases with the distance from the earth. This fact, then, would ex- plain that circumstance, and no other could. And each mol- ecule of the constituent gases being charged by the Leyden jar in the earth itself, becomes in its turn a centre of force which is readily affected by the polar forces in the earth, so that the conditions obtain for producing movement in them, the whole matter depending upon changes in polarity. It is needless to add that no amount of cold could affect this action, which is precisely what the circumstances in aerial mechanics calls for, since incessant motion pervades it all. Some idea of the enormous force which is involved in aerial mechanics may be had from the atomic weight of the constituent gases — notably nitrogen, L4 ; oxygen, 16; aqueous vapor, 18 ; carbonic acid, 44, or nearly two and one-half times greater than water ; while the pressure of the whole is equal to 33 feet of water spread over the entire surface of the globe. And yet it is all lifted up in space and borne hither, thither, in every possible direction, with the utmost ease and celerity, under the action of electrical force, as illus- trated by the rubbed glass and silver leaf, only that in the present instance the action is automatic. And proceeding upon this line of investigation, we will now take up some of the actions in the atmosphere, both as regards the currents which exist in it and the inter-molecular movements for maintaining its organic constitution, together with the cur- POLAR ACTION IN THE ATMOSPHERE. 11 rents which set in and out the flora and fauna, all which respond readily to treatment, and while the action is complex, it unravels easily by the key furnished in the polar forces Given that atmospheric matter is held in space by the inter- action of the polar forces (and which must be conceded, since there must be a force for overcoming gravitation), it follows that the various movements which pervade the atmosphere must also be due to this circumstance ; or, in other words, they flow out of the polar forces as water from a fountain, which cannot rise higher than its source. And the molecules, thus resting upon the polar forces, as the A V? Wi. %,;■. -■. a>- Fig. 4. Jloor of support against the action of gravitation, it follows that any change in polarity must necessarily affect the relations of the molecules. It could not be otherwise, in the very nature of things. No w, then, taking this as the basis of the mechanics (and everything must have a basis), we will begin with the larger movements first, proceeding thence to the inter-molecular for maintaining organic unity, thence to the actions in living- organisms. Concerning the Currents in the Atmosphere : In this investigation we are materially assisted by the re- 12 polar actio:;. searches of Faraday, by means of which the action in the atmosphere is brought clearly into view. For example, he Fig. 5. — Magnetic Lines of Force. From a Photograph by Professor Mayer. POLAR ACTION. 13 discovered, by placing a sheet of smooth paper or glass over a bar-magnet and showering fine iron filings upon it,* that they would arrange themselves in systematic order and in beautiful curved lines, extending from pole to pole (Figs. 4, 5, 6). Now, by applying this circumstance to the earth itself and the actions taking place in air and water, notably the currents setting in and out of the poles, together with the formation of the cloud strata, are at once made intelli- gible. If the earth itself be a prodigious magnet (which. Fig. 6. — Showing the "Lines of Force" extending from Pole to Pole. no one should deny, since it could not otherwise be held in space, nor motion be produced in it), and atmospheric matter is suspended in space by inter-action of the polar forces, as alleged, it follows that similar arrangements should obtain among, the molecules as in the iron filings, the same law apply- ing for both. Furthermore, that there are such k ; lines of force" stretching their long arms between the terrestrial poles, * The iron filings being very heavy, and consequently not free to move, in order to facilitate the action "the sheet is gently tapped from time to time so as to release them for a moment, and enable them to follow their tend- encies." 14 TERRESTRIAL MAGNETISM. is fully established by the action taking place in the magnetic needle, which, the moment it is suspended and free to move, trembles, oscillates and rocks from side to side, nor pauses till it is brought into correspondence with the magnetic meridian, one end pointing north, the other south, while every atom and molecule feels the pull in these polar forces; and should they be free to move as the molecules in air and water, can it be doubted for a single moment but that they would be pulled to their respective poles, the positive going one way and the negative the other ; since it is reasonable to assume the forces which coerce them in mass should be equally effective upon the indi- vidual molecules ? This, then, would explain that matter, and n > other could. Faraday ! thou incomparable ! we thank thee ! This experiment of yours with the magnet puts iron through the logic. The cloud strata, the currents in the air, and the currents in the ocean are explicable by polar action only, while it all represents forms of conversion of force. Passing rapidly over the actions, for the sake of brevity, it would explain the following phenomena, otherwise inexplicable : 1st. Why the storm-centre does not follow the isothermal lines, pursuing an erratic course, and going in every possible direction. 2d. The occurrence of violent storms in the polar regions, and their greater frequency in the temperate zones during winter. 3d. It would account for whirlwinds, in which the air pur- sues a violent rotatory motion, since this is one of the phe- nomena which accompany electrical excitement. Moreover, a miniature whirlwind is readily reproduced.* And since elec- tricity increases magnetism, this circumstance would explain the cohesive power, so to speak, among the molecules, which imparts corresponding firmness and strength to the atmosphere, :- A curious " object-lesson " is that by which Professor Douglass, of the Michigan State University, shows his classes the operation of a cycl&ne. He suspends by silken cords a large copper plate, which is heavily charged with electricity. The electricity hangs down underneath the plate like a bag, and is rendered visible by the use of arsenious acid gas, which gives it a green color. The formation is a miniature cyclone as perfect as any started in the clouds. It is funnel-shaped, and whirls around rapidly. Passing this plate over a table, the cyclone snatches up copper cents, pith balls and other objects, and scatters them on all sides. ATMOSPHEEIC MAGNETISM. 15 whereby solid masses of great weight are caught up and trans- ported to great distances in the funnel of the whirl wind. 4th. It would explain why thunder-storms are accompanied by vivid electrical phenomena and the fall of the thunder-bolt. The electrical force which suspends water in the atmosphere being withdrawn, an amount of electricity representing this circumstance passes at once to the earth, and striking the object most highly charged at the time with opposite electricity, dif- fuses itself through the earth for producing equilibrium. In fine, water falls because the thunder-bolt falls, the one produc- ing the other. 5th. It would account for the cloud corona resting over islands in the sea, and why vegetation should milk the clouds. All these circumstances, then, have ready explanation by this mechanics, and they can be explained in no other way. But we are by no means done yet; a multitude of phenomena other- wise inexplicable remain for mention. The following forcible excerpt will be appreciated : ' ' The experiments of Faraday show that the magnetism of the air changes with temperature ; that it is least near the equator, and greatest at the poles of maximum cold ; that it varies with the seasons, and changes night and day ; nay, the atmosphere has regular variations in its electrical conditions, expressed daily at stated hours of maximum and minimum tension Coincident with this, and in all parts of the world, but especially in sub-tropical latitudes, the barometer also has its maxima and minima readings for the day. So also, and -at the same hours, the needle attains the maxima and minima of its diurnal variations. Without other time-piece, the hour of the daymay.be told by these maxima and minima, each group of which occurs twice a day and at six-hour intervals. These invisible ebbings and Sowings — the diurnal change in the electrical tension — the diurnal variation of the needle, and the diurnal rising and falling of the barometer, follow each other as closely and as surely, if not quite as regularly, as night the day. Any cause which produces changes in at- mospheric pressure invariably puts it in motion, giving rise to gentle airs or furious gales, according to degree ; and here, at least, we have a relation between the movements in the air and ](') ELECTRICITY PRODUCING CIRCULATION the movements of the needle so close that it is difficult to say which is cause, which effect, or whether the two be not the effects of a common cause "* The mode of increasing the action in the air is by changing pressure, notably by developing areas of low pressure with an increase in pressure in adjacent localities, whereby fluid equilibrium is invoked, the fluids rushing in to equalize press- ure. And the greater the difference in the low and high pressures, the more violent the storm, while the whole is due to electrical disturbance. Taking the area of low pressure as the storm centre, we must regard this as due to a flood of electrical force which, by increasing polarity among the mole- cules causes them to recede farther and farther from each other, and in proportion producing aerial expansion with corresponding fall in pressure, while the adjacent fluids flow into the locality till pressure is again uniform. So, then, for producing the atmosphere itself, we need the action of elec- tricity; and for producing currents in it, we need the action of electricity; finally, for energizing the movements for producing the rapid currents, we need the action of electricity. The curious circumstance that pressure falls when the air is satu- rated with moisture, is to be explained in the same way. Thus for effecting evaporation, electrical force is, so to speak, piled up in the aqueous molecules which, by riving them widely asunder, floats them off into the atmosphere, but in place of increasing density, pressure falls in correspondence with the degree in saturation by reason of the fact that the aqueous molecules, by acting as centres of electrical force, react upon the molecules of the constituent gases, causing them in turn to recede farther and farther from each othei\ so that expan- sion and low pressure are made inevitable. Thus we have the conditions for producing expansion in the atmosphere, for increasing circulation correspondingly inherent in the very mechanics of evaporation, and the wonderful utilitarian methods in Nature, have striking illustration, the matter being also self-adjusting. In this manner the flora and fauna are fed out of the seas and the earth is watered. Finally, this * The Physical Geography of the Sea, pp. 152, 153. Maury. CHANGES IN PRESSURE. 17 mode of increasing circulation in the air by rhythmical changes in pressure effected through the action of electrical force extends as well into living organisms ; notably animals, in which it performs an enormous role, as indicated in the rhythmical expansions and contractions taking place in the organs for pumping the fluids through the structures Gam- in snsurate with the force which is expended in them. Other- Avise the universal pumping actions going on in the body would be meaningless. This en passant, as we would not anticipate. Granted that the atmospheric molecules are suspended in space by electrical induction propagated from the earth, and moving hither and thither by the action of the polar forces, and the whole is at once made intelligible, together with the currents setting in and out of the poles, the culminating points of polar force in the earth, while it all forms, so to speak, a magnetic sea in incessant motion under the action of the polar forces, which determine all the movements. And since rhyth- mical changes in polarity inhere in polar action, it follows that incessant movement is made inevitable. Then, again, the unequal distribution of solar heat produced by the spherical form of the earth, which presents only a moiety of the surface at a time to the solar beam, together with the rotatory motion upon its axis, should tend to increase the action, not only as Ibetween the equator and the poles, and opposite sides of the earth, but also the XDerpendicular movements as well, the atmosphere and earth possessing opposite polarities, the latter being negative, the former positive. And in this connection it may not be amiss to call to mind the important fact, equally suggestive, of the air circulating in the very crust of the earth itself, as also in the waters, since it forms an essential part in the economy of Nature and is needing explanation ; and were polar force eliminated from these actions, it would be utterly impossible to explain them. For example, the metals are nearly all oxidized, and numerous salts are formed, while sub- terranean waters are highly charged with the gases, notably car- bonic acid ; and making due allowance for the action of water, these results, in the main, are undoubtedly due to the action of the atmosphere, which is the source of the free oxygen 18 AIR IN WATER. and carbonic acid; while in the ocean itself air passes in a constant stream to the very floor for evolving and sustaining the life which is produced in this locality, otherwise impossi- ble. A circumstance which is also deeply interesting, since it proves incontrovertibly the existence of interstices in water ; and being nearly incompressible, it follows that water is formed of globular or spheroidal bodies in actual contact, but leaving interstices, as a matter of course, and similar to what occurs when shot are heaped together, through which fine sand is readily sifted to the bottom by means of agitation, gravitation compelling this circumstance. But the simile fails at this point, however, for the air goes down to the floor and returns in a constant stream, otherwise a balance in the gases could not bs maintained. From the very nature of the mechanics this circulation is difficult. And here comes in the great utility of the "tides" for effecting rairid admixture of the atmos- pheric gases in the water, and not a wave occurs in the ocean but contributes its part for maintaining equilibrium in the oceanic gases, while the grand scheme in Nature receives ad- ditional emphasis ; at the same time, the very principle in tidal movement shows incontrovertibly that water is dominated by polar force, the all-pervading principle in Nature for main- taining continuity in force. In proof of this, we have only to look from the actions in the mass to those taking place among the molecules, of which water furnishes eloquent example. The Actions Talcing Place in Water : The prodigious force which disappears when oxygen and hy- drogen combine in the form of water (H2 0)* prepares the mind for its marvelous performances. This substance is never still, the nearest approach being when locked in crystal structure, while perpetual motion is the eternal order ; going this way, that way, and in every conceivable direction, under action of * Faraday estimated the electrical force involved in the decomposition of a single grain of water to be equivalent to 800,000 discharges of his large Leyden bat ery in the Royal Institution. Weber and Kohlrausch estimate the quantity of electricity associated with one milligramme or the g'gth of a grain of hydrogen in water, if diffused over a cloud 1,000 metres above the earth, would exert upon an equal quantity of the opposite electricity at the earth's surface an attrac- tive force of 2.268,000 kilogrammes, or about 5.000.000 foot-pounds. POLAE ACTION IN WATEE. 19 the polar forces and to which nothing is comparable save the actions taking place in animal organisms, and in which the deeply suggestive fact is disclosed that it forms fully three- fourths of the structures, the gray matter of the brain being 80. y decimals water ; while the nutritive and force-producing elements are suspended in its midst, and transported through. the channels of the circulation by this means. Mirabile dictu I Mirabile ! Mirabile ! Rising up from the ocean in enormous volumes from the action of electrical force, it swims away in the magnetic sea, and descending to earth from a change in polari- ty or abstraction of force, it feeds the flora and fauna, the excess flowing off the water- sheds back again into the ocean, and so making the circuit of the globe in this manner under action of the special polar forces which apply ; but also rising and falling continually from the earth at the same time, while heat serves for energizing the movements by increasing polarity among the molecules, as before remarked ; otherwise is in- explicable. And sailing in the great round of its circulation in the air, at times spreading out so as to become invisible, but com- ing together again and again to form the cloud strata and the rain from responsive changes in polarity, it is at once perceived that the whole mechanics connects through and through by means of this all-pervading principle ; while electricity is the dynamic force for effecting the changes in polari- ty. Take another example. At a temperature of 2i2 degrees Fahr., water expands 1,700 times its volume, while J, 000 degrees of temperature disappear. Bat how ex- pand % and what form of force does temperature assume % We have seen that the only means for suspending matter in space, and for producing movement in it, is by electrical induction effected through the action of the polar forces which electricity intensifies, and by applying this circum- stance to evaporation and the action taking place in boiling water, the phenomena are at once made intelligible. Thus in the case of boiling water, as in simple evaporation, heat undergoes metamorphosis into electrical force, which becomes piled up as it were, in the molecules, riving them farther and farther apart, and floating them up in the magnetic sea, the greater density in the air also serving to expedite the move- 20 POLAR ACTION IN DIFFUSION. merit ; since no other force applies for suspending matter in space ami producing movement in it save electrical force, into which heat is transformed or converted. And thus supported by electric force, it follows that when this is withdrawn, as lnrppens when clouds of opposite polari- ties come in contact, the water must again condense itself and fall to the earth from the action of gravitation. Hence the electrical phenomena which accompany rain. All which is readily intelligible. Diffusion : Take the mechanics in diffusion as further illus- tration of this principle in molecular action, and see how readily this also responds to treatment. It is seen to great advantage in dissolving sugar. For ex- ample, if a lump of loaf-sugar be held against the side of a glass of water and suffered to dissolve, a current of fine saccha- rine matter, in form of a white cloud, is seen to issue from every portion of the mass and circle round and round the limits in the glass, going first toward the bottom, seemingly from the action of gravitation, but crossing over and ascending on the opposite side till near the surface waters, comes back again to the mass, then down again toward the bottom, as before, in a continuous circuit, nor pauses till all the sugar is dissolved or the water becomes fully saturated. Now, then, if polar force were eliminated, how would it be possible to explain this action? Moreover, should some ar- rangement obtain for removing the sugar as fast as introduced, no reason exists why it should not be perpetual, or why it should not belt the globe itself, had the water such extension. Here, then, we have circulation produced by polar force sim- ply, while heat serves for energizing it by increasing polarity among the molecules, and in this manner disappearing in mechanical work. In short, diffusion, whether it relate to atmosphere or water, or to substances undergoing solution, is universally the same, being due to the action of the polar forces, and which is fully corroborated by the fact that heat serves to energize the action in all of them, and showing the principle is all-pervading. Osmose and Capillarity : Continuing the inquiry, take .osmose and capillarity, circumstances so much relied upon for POLAR ACTION IN" OSMOSE. 21 effecting circulation in living organisms, but, examined criti- cally, what essential principle does either represent ? As a matter of fact, they express nothing further than that fluids pass through membranes and traverse interstices, while they leave out altogether the potential factor for compelling them to do so, and why heat should energize these actions also ; not to mention the manner of connecting them with the great circulation taking place in the globe itself, upon which they are dependent and with which organic unity is main- tained. At the same time, however, we have to note the curi- ous circumstance that physiologists, in seeking to explain osmotic action, have constant recourse to the nomenclature in polarity, which at once concedes the point at issue, if, for- sooth, language means anything at all. In fine, the endos- mometer is based upon the '* affinity" of the fluids for one another, and the powers of "attraction" exerted on the part of the membranes for the fluids. And should ' ' affinity ' ' and '•attraction" be eliminated, what would become of osmotic action and the endosmometer ? Then, again, in speaking of diffusion, which is essential to osmose, we note language of similar import, to wit : ' ' When the water reaches the inner surface of the membrane (containing alcohol), it instantly diffuses itself into that fluid, partly in consequence of the mutual repulsive force of its own particles, and partly from their affinity to those of the alcohol." Italics are added. Further comment is unnecessary. Now, then, in regard to capillarity. Is it not true that water, after passing into a corner of a dried sponge and diffusing it- self through the mass, passes out again at the surface to join the great mechanics in the atmosphere, expanding and rising up in this by what is known as evaporation ? while heat ener- gizes the movement. That so long as this relation of the parts shall continue, so long will this miniature circulation be main- tained. Ceasing, by removal of the sponge from the water, the former speedily becomes dry and crisp again, as the flora in iatal drought. But the rapidity with which water at first enters the sponge ! — how is that circumstance to be explained % The answer is also readily given : The old relationship subsisting between them 22 POLAR ACTION IN CAPILLARITY. being broken up, asserts itself the first opportunity that pre- sents, the water rushing into the sponge under the powerful action of the polar forces intensified by electrical induction, the atmosphere being more highly electrical ; otherwise it would not be a gas. The dried sponge, then, compels water into it- self with great avidity when connection is made, not by reason of the canal system and interstices existing in it, which facili- tate the transit only, but because of the energy in the polar forces of its molecules, which are highly charged with oppo- site electricity, the aqueous molecules passing on immediately the affinities are satisfied, to make room for those pressing on behind in ceaseless procession, passing out at the surface again into the great mechanics ; the supply ceasing, the sponge speedily becomes dry and crisp again, the pulling '-force in the atmosphere and the pushing-force in the sponge produced by repulsion, compelling it all out to the very last molecule it is all simple enough. In fine, all these actions must be accounted for in a theory of circulation, and if polar force were ex- cluded, it would be utterly impossible to explain them. Last, but not least, with the extinction of the solar beam as the source of electrical supply, there could be no molecular actions as involved in the movements in fluids, consequently there could be no life, showing conclusively that the principle under- lying it all is electrical and polar. CHAPTER II. THE FLORAL CIRCULATION. Principle in the Floral Circulation— Action of the Polar Forces and the Mode of Increas- ing it — Physiological Experiment Demonstrating the Energy of the Polar Forces in Flora — Circulation in Flora Comparatively Slow— Deduction to be Drawn There- from—Explanation for the Rapidity of Circulation in Fauna and the Amount of Food Consumed by Them. Perceiving an organic connection subsisting between circu- lation in air and water and circulation in living organisms, we have only to apply the preceding principles to circulation in trees in order to make this also intelligible and easily under- stood. For example, one end of the growth is rooted in the earth, while the other extends to variable distances in the atmos- phere, and the former being negative and the latter positive, the conditions obtain for producing circulation between the two ends. Furthermore, the laws of electrical induction should tend to increase this action, for the reason that the atmosphere being positive, this should compel the positive electricity in the bole and branches into 'the roots and root- lets and pull all the negative electricity in the latter into the bole and branches and terminal leaflets ; and being thus differentiated in electrical force, the highest conditions obtain for producing circulation in-and-out the two ends, since it would effect opposite polarities in the branches and the atmosphere and in the rootlets and the juices in the earth, thus connecting the mechanics through and through, and producing continuity in force, which the scheme calls for. The fluids being in immediate contact with the cell- walls in the two ends, the molecules are readily drawn through the thin places in the walls left for the purpose, and being once in "he 24 POLAR ACTION. channels of the circulation, pass readily up and down the structure under the action of the polar forces, upon the same principle precisely as obtains for producing circulation of air and wa ter in the globe itself, out of which the growth is evolved. Furthermore, it would explain the enormous force which is in- volved for producing circulation in mammoth trees; e. g., the giants of California, some of which are said to be four hun- dred and fifty feet in height and ninety feet in circum- ference, and in which tons upon tons of sap are kept in motion from end to end of the mighty growths, since the force which maintains air and water in a ceaseless circuit round the globe itself is commensurate with this circumstance. Then, again, it would explain the oscillations in this circu- lation with the waxing and waning of solar force, heat being necessary for energizing molecular action by increasing the polar forces. Thus, with the return of spring, the vernal heat and moisture, the sap leaps up the tree, and the whole noise- less clockwork is again set in motion, the buds swelling and bursting into foliage, while the deep sleep of winter is brought to an end ; the matter obviously depending upon temperature for energizing the polar forces. But take the action in the cell itself as further example. Thus when the cell of a succulent plant is examined under the microscope, a distinct circulation is seen to be taking place within it, the fluids passing first up one side, across the upper end, then down the opposite side of the cell in a continuous circuit under the action of the polar forces ; a miniature, in short, of the great circulation taking place in the globe itself, out of which it had been evolved. And looking thence to the circulation taking place in the plant itself, it is at once perceived that this also is but an extension of the same principle of motion, the fluids in the cell-empire, as in the case of the individual cell, passing first up one part, then down another part of the growth, and so round and round the limits in the plant in a continuous circuit under the action of the polar forces, while heat serves for energizing the movement, the same as in air and water. This circumstance may be seen to great advantage in a maple orchard in the early spring, when the sap is running up: With the object of obtaining this sap, holes one-half inch in ENEKGY OF POLAR ACTION. 25 diameter and about one and one-half inches in depth, so as to penetrate the newest wood, are made in the bole of the tree by means of an auger. A large tree, or one approximating two feet in diameter, contains about 24 such holes, with elder spouts for conveying the water into a receiving vessel at the foot, commonly an excavated section of a tree improvised for the purpose, and remaining from year to year, though, of course, fresh holes are made every year. The water trickles through these spouts in a tiny stream. Now, then, the point we wish to make is, that during night-time, when temperature falls, the flow nearly ceases, and when this approaches the freezing point, it stops altogether ; while during the day-time, when temperature rises, it sets in again, increasing more and more as day advances, till about 3 p. m., when the maximum is reached, which corresponds with the maximum of tempera- ture. From this time on it grows less and less, with the de- cline of solar force, till night sets in, when the sudden fall in temperature brings it nearly to a standstill. On a bright, warm day following a cold night the flow is very rapid, a very strik- ing illustration, indeed, of the intimate relations and direct dependence of the floral circulation upon temperature, and which, of course, must act by increasing polarity in the plant and fluids ; otherwise is inexplicable. Finally, a ready means obtains for measuring the energy of the polar forces in the plant, by repeating the physiological experiment adopted by Hales. For example, he discovered "that a vine, cut in the bleeding season, will push its sap up a glass tube as high as 21 feet above the surface of the stump." Now, then, since there are no leaves to draw upon the sap by evaporation, it follows that the lifting-force to this great column of sap, and which, of course, would include the air standing upon it in the open end, must be due to the action of the polar forces simply, no other force applying for producing it. Some evaporation takes place in the open end, it is true, but the circulation is greatly in excess of this, the sap rapidly accumulating till a column 21 feet in height is reached, where the point of equi- librium is reached, and a balance is struck between the action of gravitation and the action of the polar forces, the two being antagonistic ; the weight in this column of fluid being the 20 POLAR FORCES IX FLORA. measure of the energy of the polar forces in the terminal ends or poles in the vine, otherwise is inexplicable. Of course, evaporation from the surface of the leaflets in- volves corresponding absorption in the rootlets, for maintaining a balance in the circulation, in this manner increasing circula- tion in proportion to the evaporation taking place; but it would not explain why the tree fills up with sap before there are any leaflets and out of which the leaflets themselves are formed ; while it leaves unexplained the principle in evaporation for connecting the internal with the external mechanics, which the scheme calls for, continuity in force demanding this. And not water only, but the oxygen which is disengaged in the nutri- tive processes from carbonic acid, and is passing out from the surface of the leaflets in a constant stream, the molecules promptly taking up their relative positions in the atmosphere; while carbonic acid is compelled in the tree by the same means, n fine, that there must be some universal and all-pervad- ing principle in nature for connecting the prodigious clock- work through and through, and bearing upon every piece to the very molecules and atoms themselves, since it is through them the masses, living or non-living, are built up and sustained, or are pulled down and again redistributed. There is no diffi- culty, then, in accounting for circulation in flora any more than there is in accounting for circulation in the air and water out of which they are evolved, while all the phenomena fall readily into line in regular order and succession, and leave no out- standing quantity refusing absorption. And in this connec- tion we should not fail to notice a deeply suggestive fact, namely : why water should pass out at the leaflets in a con- stant stream by evaporation, and if not as rapidly renewed by a similar stream passing in at the rootlets for maintaining a balance, the plant would speedily become dry and crisp, as oc- curs in fatal droughts. This also is easily answered. Since water is the medium of transportation for the nutritive and force-producing elements, it follows when these are withdrawn by the nutritive and functional processes, that a correspond- ing proportion of water should be discharged in order to make room for the fresh water and supplies coming into the organ- ism; the one involving the other, as in no other way could a CIECDLATIOlSr AND NUTRITION. 27 balance bo maintained, water being the medium of transporta- tion Otherwise nutrition and function would have arrest from the absence of the gases and the alkaline earths and minerals dissolved in it by action of the polar forces. In the fauna a comparatively large amount of water is being thus discharged from the surface for the purpose of regulating body- temperature, for which a physiological balance obtains in the organism, being the most effective means of doing this, a high temperature being inimical to life. Thus during exer- cise, which tends to put up temperature, the skin becomes flushed for cooling the blood; at the same time is bathed in per- spiration. But this matter is more fully treated in another place. Concerning the Rapidity of the Floral Circulation and the Deduction to be drawn therefrom : The fluids having to pass from cell to cell by means of thin places in the walls left for the purpose, each cell forming a separate and distinct com- partment in itself, it follows that circulation in flora is com- paratively slow. Still, this is sufficient for the nutritive processes simply, which require a slow circulation to afford opportunity, so to speak for crystallizations to take place in the formative processes ; whereas, in animal life, the very opposite obtains, the purpose here being the generation of force, which is expended in producing the multitudinous ac- tions taking place in them, since everything is evolved out of circulation, which is made commensurate with the special physiological requirements. Hence, the differentiation of a vascular system, together with the special arrangements that obtain in them for compelling circulation to be in correspond- ence with the amount of force which is expended in producing the various movements, and which are classified as voluntary and involuntary, or animal and organic, but all of which are directly dependent upon circulation, as must appear obvious. The point we wish to make is, that the nutritive processes require a slow circulation, and in proof of this fact, we have overwhelming evidence furnished in the flora, notably in the case of a pumpkin weighing 265 lbs., which was produced in a period of less than 60 days from the time of flowering, and that upon a vine but a little more than an inch in diameter.* * All the buds are pinched off save the one selected. 28 CIRCULATION AND FORCE. In succulent plants, such as grasses, peas, beans, etc, growth is very rapid. And in many others as well ; e. g. , melons, goiu-ds, roots or tubers. The fruits also. So, then, nutrition per se does not require a rapid circulation, and sufficient only to effect the accretions and crystallizations for producing growth, inclusive of the arrangements in the structures for prod ucing motion which animal life involves. And we make the deduction for animal life, for the reason that the principle in nutrition is the same, and must be so in the very nature of things. Namely, the action of the polar forces for pulling the molecules into position and locking them in the structures, a slow circulation favoring this action. Consequently, nutrition goes on most rapidly during sleep and repose, when circulation is slowest. But for evolving force in the organism for producing the multitudinous actions taking place in the body, calls for a rapid circulation to make it commensurate with this circum- stance, the two being necessarily in correspondence, for in no other way could a balance be maintained. It calls for considerable expenditure of force ; hence, the amount of food consumed, especially by warm-blooded animals, the maintenance of temperature alone calling for large supplies, as this approximates 100 degrees Fahr.; in many animals, birds especially, it runs a number of degrees higher. In this, too, there is variety, as in everything else, animate and inani- mate, variety being the one pronounced circumstance in Nature. This brings us to the means for increasing the animal circulation, commensurate with the force which is expended in them. CHAPTER III. THE ANIMAL CIRCULATION. Principle in the Animal Circulation — Adjustment with Pressure and the Power of Pro- ducing Rapid Rhythmical Changes in Pressure, the Law in the Animal Circulation — The Movements in Respiration : Heart, Arteries, etc., Pumping- Actions for Increasing Circulation, the Whole Forming a Connected Movement for Increasing Circulation Between the Cell-Brood and Environment, whence the Nutri- tive and Force-Producing Elements are Derived, and into which the Waste Products are Returned — Explanation for the Correlation of the Vaso-Motor and Voluntary- Motor Centres with the Respiratory Centre — Mechanics in Inspiration and Expira- tion— Two Respiratory Movements Performing at the Same Time ; One in the Lungs, the Other in the Tissues — Physiological Experiments, Showing that Pressure is the Fundamental Circumstance in the Animal Organism, with which Everything has Adjustment, and that the Actions in the Lungs, Heart, Vessels and Hollow Viscera Relate to Changes in Pressure for Compelling Movement in the Contents : i. e., for Increasing Circulation — Otherwise are Meaningless. We are now in a position to take up the animal circulation and explain the phenomena appertaining to it ; notably, the actions in respiration and in the heart and blood vessels, together with the whole scheme in animal structure and func- tion. But in addition to the mechanics for effecting circulation in plants — namely, the action of the polar forces — we will now have to introduce the principle of change in pressure, before alluded to for increasing circulation in the air, only that the action is here confined within narrow limits and is rapidly repeated, said circumstance being announced by the pumping movements in respiration and in the heart and blood vessels, which relate to rhythmical changes in pressure for increasing circulation commensurate with the physiological requirements, hence rising and falling in correspondence with these ; other- wise are meaningless. In short, the animal circulation is BASED UPON PRESSURE AND THE POWER OF PRODUCING RAPID RHYTHMICAL EXPANSIONS AND CONTRACTIONS IN THE ORGANS FOR CHANGING PRESSURE, WHEREBY THE COMMERCE IS COM- 30 THE LAW IN THE ANIMAL CIRCULATION. PELLED IN THE VESSELS AND THROUGH THE TISSUES WITH COR- RESPONDING ENERGY, THE FLUIDS FLOWING FROM HIGH TO LOW PRESSURE IN CONFORMITY WITH ORGANIC LAW. Hence the mechanical principle in respiration for compelling the air in and out of the lungs, is the same as in the heart and blood vessels for speeding the blood between the lungs and the cell- brood, the workmen in the tissues and objective point of all the supplies. Moreover, they form a connected movement, as in no other way could a balance be maintained. In other words, the pumping action in the lungs and abdomen for com- pelling the force-producing and nutritive elements in the vas- cular channels calls for these pumping actions in the heart and vessels for circulating them, for in no other way could it be produced. And but for this power of producing rapid rhythmical changes in pressure in the organs and tissues for increasing circulation development would inevitably have arrest at the iiora, since no other means obtains for increasing circu- lation commensurate with the physiological requirements in animal organisms ; while the speed of the currents thus pro- duced has determination, by the rapidity and energy of the pumping actions taking place in the organs, and pervading the entire body, exclusive of the bones and cartilages (the frame- work of support to the soft tissues), in which circulation is analogous with that in plants. And while the scheme is comprehensive, involving multitudinous arrangements in the organs and tissues for producing the actions and for unifying them, still it is all simple enough and easily understood. Of course, it would naturally include the digestive and assimi- lative functions, with the secretory and excretory, for it all relates to circulation and the maintenance of a balance in the organism. And since pressure, by reason of the com- pressibility of the tissues, is transmitted through the body upon all the organs to the minutest histological elements and cells, it is at once made available for increasing circulation, commensurate with the physiological requirements. Hence, the universal pumping actions taking place in the body, as be- fore remarked. This necessity for increasing circulation in the fauna, over and above what takes place in the flora, in order to make it commensurate with the force which is expended in THE LAW IN THE ANIMAL CTECTJLATION. 31 them, is sufficiently obvious ; since every variety of motion involves a corresponding expenditure of force for producing it, while this in turn is evolved from the chemical combina- tions of substances which are carried into the organism by circulation — notably oxygen and carbon — the waste products being carried out by the same means. Hence, the greater the expenditures of force, or the more rapid the voluntary move- ments, the more rapid are the actions in the lungs, heart and blood-vessels for making circulation commensurate with this circumstance, the whole being in correspondence, for in no other way could a balance be maintained. Thus, in the recum- bent position, the action in the lungs, heart and blood-vessels is lowest ; but the instant the erect position is reached, there is considerable increase in the action for promptly supplying the in- creased expenditures which this calls for, while there is progress- ive increase in correspondence with the swell in the activities, therefore is greatest when the animal is running. In other words, pressure is invoked in the measure of the requirements by means of these pumping actions. But in the absence of this law of pressure upon which to base the mechanics, it were as utterly impossible to explain the relative phenomena, ana- tomical and physiological, as it would be to account for the strong, bony skeleton, with the powerful levers and muscles, for effecting locomotion in land animals in the absence of gravitation for compelling this circumstance ; the one no more than the other. Proceeding upon this line of investigation, then, we shall pass in brief review the scheme in the animal circulation, thence to the special phenomena in detail, in which will be clearly shown the admirable simplicity and mar- velous perfection which characterize the mechanics through- out, and why everything is just as it should be for producing the mechanical work involved in the circulation, thus furnish- ing overwhelming proof of the correctness of the premises, making the argument unanswerable. We begin with the nervous centres for operating the mechanics and unifying the movements, in itself furnishing the highest order of evidence in support of the theory, being means to ends. 32 CORKELATION OF NERVOUS CENTRES. Fjjplanation for the Existence and Correlation of the Three Great Nervous Centres at the Base of the Brain in the Medulla Oblongata, notably Respiratory, Vaso-Motor and Voluntary-Motor Centres: This relation which the animal organism sustains to pressure enables us to offer a scientific explanation for the existence and correlation of the three great nervous centres at the base of the brain in the medulla oblongata for operating the mechanics, or the respiratory, vaso-motor and voluntary-motor centres ; otherwise inexplicable, and which is briefly as follows: Respiratory Centre. — Since respiration is the great pump- ing action for compelling the fluids in the organism, it is manifest that this calls for a common nervous centre for pro- ducing and coordinating the action in the lungs and con- taining walls, to the end that air and blood may be pumped through the lungs for respiratory purposes, and which would also include the force-producing elements in the intestinal canal, since it is by chemical combination of oxygen with carbon that force is generated, a measure of oxygen calling for a measure of carbon in order to effect it. Hence, this respiratory centre, together with the large pneumogastric nerves extending thence into the abdomen for connecting and coordinating the viscera with respiration. Of course, there must be a philosophic reason for these nervous combinations, or one based upon organic law, as they are persistent and uni- versal. It does not follow that heat is generated in the lungs, which is not the case, only that intestinal absorption should be in correspondence with respiration for maintaining a balance, otherwise impossible. Vaso-Motor Centre. — Several reasons make the existence of the vaso-motor centre an absolute necessity, namely: 1. It is necessary for coordinating the blood-vascular system with respiration in order to produce an uninterrupted current of the blood from the lnngs to the tissue territories for maintain- ing a balance between supply and demand ; otherwise this could not be done. In other words, the pumping actions in the heart and blood vessels must have adjustment with the pumping actions in the lungs for producing correspondence, CORRELATION OF NERVOUS CENTRES. 33 the one necessarily having adjustment with the other, as must appear obvious. Hence, the existence of this centre, together with its correlation with the respiratory, lor in no other way could continuity in force be produced. 2. Since the vessels expand and contract upon their contents for increasing or diminishing the blood for regulating the local actions which are ever changing, it follows that there must be a means for limiting the local supplies and regulating the movements throughout so as to maintain a balance ; otherwise, some parts of the system would have more blood than necessary, while other portions would suffer from dangerous ansemia ; hence, this vaso-motor centre for compelling circulation in the measure of the requirements. 3. Last, but not least, the hign pressure in the arterial system for increasing circulation in the capillaries tends to produce dangerous accumulations in the venous system, where pressure is low, and since there is a norm of blood which is kept in constant motion, it follows there must be some means for regulating the capacity of the venous system, which is something like four times as great as the arterial ; hence this vaso-motor centre for regulating that circumstance also. Finally, the whole is set to respiration, for this is the great pendulum movement in the clockwork with which everything must have adjustment, since it is the means for compelling the commerce in the organism, while the heart and vessels function as a carrier. 3. Voluntary-Motor Centre. — The existence of the vol- untary-motor centre, together with its correlation with the respiratory and vaso-motor centres, is also easily understood. Thus, since every movement involves a corresponding expendi- ture of force for producing it, and this is evolved out of circu- lation from substances brought into the organism by this means, it follows that respiration and the actions in the heart and vessels must be in correspondence with the voluntary movements in order to maintain a balance between supply and demand, for in no other way could this be done ; hence the correlation of this nervous centre with the other two centres so as to produce continuity in force, which the scheme calls for. In fine, respiration and circulation together form the basis of the activities, consequently the latter must have adjust- 34 CORRELATION OF NERVOUS CENTRES. ment with the former. Hence the correlation of these nervous centres in the medulla oblongata. The necessity for producing and coordinating the voluntary movements would, of course, explain the existence of the voluntary-motor centre, but at the same time it would not account for the correlation of this centre with the other tw< > centres. In this manner, then, that vexed problem in physi- ology has scientific explanation, and it is at once seen these nervous combinations in the medulla oblongata are inevitable from the very nature of things, the law in the circulation and continuity in force alike compelling this circumstance. Thus with a common law underlying it all, and the same principle in mechanics for increasing circulation — i. e., rhyth- mical changes in pressure — it is manifest that correspondence in the structures is also made inevitable, or that similar arrangements should obtain in the animals for producing cir dilation and the voluntary movements. And this would include not only the systemic mechanics, but the anatomical disposi- tions in the walls of the organ as well ; while this again would have determination by the character of the work, the nature of the contents, and the amount of force which is required for com- pelling movement in them in the rule of the special functions, so that all is readily explained and made intelligible. Indeed, this principle for increasing circulation must apply to the very cells themselves, which expand and contract under stimulus for producing afflux and efflux of the fluids in which they are submerged, for in no other way could circulation be increased within the cells for increasing metabolism. Finally, each organ by possessing separate and independent local nervous centres appertaining to its own special functions, but connecting with the systemic apparatus, enables the local actions to be increased or diminished as occasion may require, •without interfering with the general functions. As the me- chanics are fully brought out and explained at the proper time and place in the text, it will not be necessary at this early stage to do more than briefly refer to the cardinal cir- cumstances in order to prepare the mind of the student for the radical changes introduced in present physiology, and which lie will at once see are not only logical and necessary, but un- MECHANICAL PRINCIPLE IN RESPIRATION. 35 avoidable. First of all, however, let Mm get himself right by emancipating and disenthralling his mind of all prejudice tending to mar the judgment and obscure the mental vision, to the end that he may listen to reason and weigh evidence dis- passionately; otherwise, at very best he is but partly rational, his opinion to be little depended upon and unworthy of respect. After he has done that, let him lay firm hold of this law of pressure underlying the animal organism if he would under- stand the phenomena in animal mechanics, since they all relate to this fundamental force in nature. Now, then, it being true the body has special adjustments with pressure, while the law in the circulation consists in rapid rhythmical changes in pressure, it remains to inspect the phenomena from this stand- point, commencing with respiration, the initial action for com- pelling the commerce in the organism, as before remarked. Import of Inspiration and Expiration. — Briefly, Inspira- tion is the effort to develop a lower pressure in the lungs than exists externally ; in consequence, the air and blood flow into the low-pressure area till pressure is uniform, the amount so flowing in being the exact measure of lung ex- pansion ; no more and no less : while Expiration is the effort to develop a higher pressure in the lungs than exists externnlly, when the air and blood in consequence flow out of the organs till pressure is again uniform, the amount so flow- ing out being the exact measure of lung contraction ; no more and no less. In this manner, then, a dual circulation of air and blood is maintained through the lungs for respiratory purposes, the former flowing in by way of the trachea and the latter through the right side of the heart and pulmo- nary artery during inspiration ; but during expiration the air flows out by reflux action through the route of ingress to the environment, while the blood itself passes through the four pulmonary veins into the left side of the heart and arterial system on its way to the cell-brood in the tissues. But the great inertia in the blood calls for the expenditure of considerable force for bringing it into correspondence with the circulation of air in the alveoli, the obvious purpose being to maintain fresh air and venous blood in close proximity, for effecting mutual interchange. Hence the numerous 36 MECHANICAL PRINCIPLE IN RESPIRATION. muscles and nerves in the heart and blood vessels for increas- ing circulation in the lungs and in the tissues and for coordinat- ing them with the actions taking place in both localities, a cir- cumstance which is fully brought out further on. But in order to produce these dual circulations of air and blood through the alveoli, it is absolutely necessary for the lungs and containing walls to expand and contract together or simultaneously, for in no other way could the requisite changes in pressure be produced within the alveoli for compelling afflux and efflux of these fluids, neither could a balance in pressure be maintained in the pleurse for obviating effusions in these cavities, other- wise inevitable ; and which should speedily put an end to respiration by preventing lung expansion ; such concert of action in the parts being effected by the nervous apparatus, notably the pneumogastric, intercostal and phrenic nerves and the so-called organic or sympathetic system, which is intimately connected with the lungs, and undoubtedly serving for coordinating these actions. The mechanics is compre- hensive but easily understood, the law in the circulation com- pelling these arrangements for maintaining a balance and keeping the fluids within their channels ; otherwise impossible, since they flow from high to low pressure in conformity with universal law. And all these nerves being correlated in the medulla oblongata, harmonious action throughout is readily produced. And which, of course, would include the vaso- motor system, together with the nerves to the heart for bringing the blood into correspondence with the circulation of air in the lungs. In this manner, then, these wonderful nervous ccmbinations in the medulla oblongata are readily explained, and they can be exiuained in no other way. And not this circumstance only, but all the anatomical dispositions which obtain in the organs for producing these actions as well, being means to ends simply ; furthermore, they cannot be explained in any other way. Thus everything is in correspondence, and nothing is left out. And this should be the case, since the mechanism is necessarily founded upon law ; hence every piece in the comprehensive clockwork must have definite adjust- ments and relations with the rest, as must appear obvious. In short, a physiology which does not explain anatomy is no LUNGS AND VENOUS SYSTEM. 37 physiology at all. But in the absence of the fundamental principle upon which the mechanics is based, of course this would be impossible. The animal organism being founded upon pressure, while the law in the circulation consists in rapid, rhythmical changes in pressure, as alleged, it follows that the pumping action in the lungs should compel simultaneous afflux and efflux of air and blood in the alveoli, since both fluids freely communicate with these chambers through a special tubular system arranged for the purpose, the heart not interfering with but rather assisting this mechanics by putting additional force upon the blood, and which its greater inertia calls for, as before remarked ; at the same time the heart itself is coordi- nated with the lungs, both doing inspiration and expiration, so that in nowise is the action in the lungs interfered with by the action in the heart, the special functions in which will be described later on, and their true relation to the circulation fully shown. The following diagram of the venous system, showing the relations it sustains to the lungs (Fig. 7), will serve for im- pressing the matter For examine, the air {L) and the venous blood (A, A, A) freely communicate with the alveoli ; hence, when the lungs expand during inspiration for reducing press- ure in the alveoli, the air and blood, coming from opposite directions, must flow into these chambers simultaneously till pressure is uniform, pressure compelling them to do so. Upon the other hand, when the lungs contract during expiration for increasing pressure in the alveoli, the air and blood must flow out of these compartments simultaneously till pressure is again uniform, the one by reflux action through the route of ingress, the other into the left chambers of the heart and arterial system, the valves at the right side of the heart compelling this circumstance by preventing reflux, as in the case of the air in the air passages. From this arrangement, then, it is very readily perceived that currents of air and blood should flow in and out of the alveoli simultaneously during respiration, the one necessarily involv- ing the other. But to this we must add the arrangements in the heart and vascular system for bringing the blood into 38 LUNGS AND VENOUS SYSTEM. correspondence with the circulation of air in the alveoli, there being a given measure of each, for which special adjustments obtain in the compartments, as also for producing an uninter- rupted flow of blood through the lungs, and the whole scheme in respiration will be readily apprehended. First of all, let it be understood that the generation of force in the organism j Fig. 7. — Diagrammatic representation of the Venous System, showing the relations it sustains to the Lungs. A, A, A, venous system represented as pyramids, with the bases in the tissues and the apices at the heart and lungs (E, C) ; B, pulmonary- artery ; D, trachea ; F, diaphragm ; L, atmosphere. is the purpose of all these arrangements, and this can only be done by means of the pumping actions in the lungs, with which everything must have adjustment ; hence would include the intestines with the blood-vascular and lymphatic systems, TWO EESPIRATORY MOVEMENTS. 39 since it all relates to circulation and the supply of the cell- brood in the tissues, through whose agencies the special phenomena are evolved. Finally, we have to mention the existence of two respiratory movements performing at the same time in the body, notably one in the lungs, the other in the tissues ; the former for pump- ing the commerce in the organism, the latter for pumping it in and out of the tissues for the due supply of the cell-brood and removal of waste products ; while the vascular system, inclu- sive of the heart, functions as a carrier between these two poles in the circulation, with which they are coordinated by means of the nerves extending over them and connecting them with the medulla oblongata, the vaso-motor and respiratory centres, whence force is propagated over all the structures, to the end that a current of blood may be maintained between the cell-brood and environment for the due supply of the nutritive and force-producing elements and removal of waste products. The composite character in the arterial- tracings, or the existence of respiratory, cardio-arterial and dicrotic or capillary waves, which are superposed, one upon the other, in the order named; or the respiratory, by the cardio-arterial, and the latter by the capillary or dicrotic waves, is to be explained by this circumstance. In fine, these waves or respiratory pul- sations are throbbed over the vessels from the respiratory centre in the medulla oblongata, by means of the nervous plexuses, extending over the vessels. "Traube's Curves," together with the physiological problem connected with the curves in arterial and intra-thoracic pressure, are readily explained. By means of this law of pressure underlying the organism, then, all this is easily accounted for and made intelli- gible; otherwise is utterly inexplicable. The most incontro- vertible evidence of rhythmical expansions and contractions taking place in the arteries and capillaries, synchronous with respiration and the action in the heart, is submitted, placing this function in the vessels, beyond the shadow of a doubt or the possibility of mistake, at the same time the common rela- tion which it all sustains to pressure is too obvious for con- troversy. Last but not least, we have to note the deeply significant fact 40 ARTERIAL PRESSURE AND DEVELOPMENT. of an increase of pressure in the arterial system with pro- gress in development, notably in warm-blooded animals. Thus, when a cold-blooded animal is decapitated, the blood issues very slowly out of the open ends of the vessels, oozes and wells out simply, trickling down in a tiny stream upon the ground, dark and venous in appearance ; whereas in the case of a warm-blooded animal it spurts out to a considerable dis- tance from the body in a sustained stream, which issues per saltam or in a succession of leaps, the latter being due to rhythmical contraction in the vessels for increasing pressure, while the former is due to the permanent high pressure which exists in the arterial system for increasing circulation in the tissues, at the same time it functions as the ms a tergo to the venous system for compelling the venous blood toward the lungs, thereby assisting the action in those organs and in the heart, which act as a suction-force upon it and constitute the Tis a f route; to which must be added the action in the veins themselves, which are muscular and richly supplied with nerves connecting with the vaso-motor and respiratory centres. Well, the blood in the arterial system of warm-blooded animals is not only under high pressure, but is also more highly oxygen- ated, being of a bright red color, the two going together — the high pressure with the increase in oxygen. So that we have an arrangement for increasing circulation in the tissues with an arrangement for increasing metabolism, the two being in cor- respondence. And we can see why this also should be as it is. Since it relates to the generation of force, there would be nothing gained by increasing circulation in the tissues in the absence of the oxygen ; hence, this special combination for evolving force in the organism. But why in the warm-blooded animal m ore than the cold % This also is easily answered. Thus, in the case of the cold-blooded animal the body lies prone upon the ground, the movements are sluggishly and awkwardly per- formed, while respiration is imperfect and digestion slow and delayed. On the other hand, in the case of the warm-blooded animal the body is suspended off the ground by means of the crura, which involves a tremendous struggle with gravitation, while the animal is in constant motion and the movements energetic, and which, of course, would call for a corresponding ARTERIALIZATION OF THE BLOOD AND DEVELOPMENT. 41 amount of force for effecting these actions ; hence the increase in the respiratory and digestive functions, together with the high pressure in the arterial system for increasing metabolism, for in no other way could it be done. Again everything is in correspondence. * A highly interesting and important fact in the animal cir- culation is the presence of iron in the red corpuscles in the form of haemoglobin, for increasing polarity, whereby oxy- gen is more readily pulled into the organism and carbonic acid expelled from it ; since it is not a chemical union which is effected with these gases, but one in which the molecules are in light contact simply, the haemoglobin readily yielding up the oxygen in the tissues, while the carbonic acid is easily displaced by the oxygen when the venous blood is exposed to the air. And by reducing pressure simply, as in a receiver and air-pump, oxygen escapes from the corpuscles. The great com- plexity in this albuminous compound (C 54.0, H 7.25, N 16.25, Fe 0 .42, SO .63, O 21.45 — Hermann), and which, of course, is necessary for producing the polar conditions spoken of, makes this one of the most wonderful adjustments in the body. But this matter is more advantageously treated in connection with development, to which the reader is referred, the more im- mediate object in hand being to show the law in the circulation and the relations it sustains to pressure. Showing that the Animal Fluids Respond to Changes in Pressure. — Before proceeding to make application of the pre- ceding principles for elucidating vital phenomena, anatomical and physiological, it might not be amiss to call to mind familiar circumstances of every-day occurrence, which establish incontrovertibly the important fact that the animal fluids re- spond to changes in pressure, and showing conclusively that it is fundamental in the animal organism, thus fully preparing the mind for what is to follow in the text. For this purpose we have prepared the following illustrative diagram (Fig. 8). For example, it would scarcely be contended for a single mo- ment even that the principle which applies for aspirating the secretions in the mammary gland by means of the breast-pump * For the rest the reader is referred to the work " On Gravitation and Develop- ment," where many other matters come up in this connection. 42 PRESSURE FUNDAMENTAL IN THE BODY. (B) is not identical with that in the ordinary syringe (A), the fluids in both cases flowing into the instruments by reason of the low pressure which is developed within them and with which they communicate, till pressure is uniform. Indeed, the very tissues themselves are compressed, pushed and squeezed into the breast-pump in order to equalize press- ure, external force compelling this circumstance. But a yet more forcible illustration is furnished in the case of the ordinary cuprjing-glass (E). In this contrivance the air in the cup is rarified simply by the burning alcohol, when the instrument is suddenly inverted over the parts, which are at once forcibly compressed into it, the blood at the same time flowing rapidly into the imprisoned structures in order to equalize pressure, till the distended and swollen capillaries burst with their contents, producing the characteristic ecchy- moses, so great is the energy in this force when suddenly devel- oped. And since there is no power in the body to prevent this abnormal current in the blood and juices, it follows that pressure is the fundamental circumstance in the organism with which everything must have adjustment. Indeed, it furnishes a crucial test of this fact ; while the actions taking place in respiration, in the heart, arteries and hollow viscera, are to be interpreted from that stand-point ; otherwise are meaningless. In fine, but for this adjustment, with pressure and the power of producing rapid rhythmical changes in pressure, animal life would be utterly impossible. And it applies not only to respiration and the actions in the heart and vessels but to deglutition, defecation, urination — in short to all the hollow viscera, since they all relate to circula- tion, and the maintenance of a balance in the organism ; other- wise these actions also would be meaningless. Thus in the case of the nursing infant (B) can it be doubted for a single moment even that the same principle applies for compelling the mammary secretions in the mouth-cavity, as in the chamber of the breast-pump (B), or the production of a lower pressure in the cavity than in the mammary gland, the fluid flowing from high to low pressure in conformity with universal law \ (And it is more than probable, as the PRESSURE FUNDAMENTAL IN THE BODY. 43 secretions are being thus withdrawn, that the irritations pro- pagated from the skin-surface are reflected thence upon the milk ducts, which causes them to contract for increasing press- ure, whereby the flow into the mouth-cavity is expedited). Furthermore, that the same principle applies for compelling them thence into the stomachal cavity represented in the Fig. 8.— Familiar Modes of Pumping the Fluids out of the Body, showing that they respond to changes in pressure. warns of deglutition, which consist in an anterior expansion for diminishing pressure with a posterior contraction for in- creasing it, whereby the journey of the fluid or the bolus along the canal is greatly expedited, the waves following each other in rapid succession till the stomachal cavity is reached. In 44 PRESSUBE FUNDAMENTAL IN THE BODY. short, that deglutition is based upon rhythmical changes in pressure, otherwise is inexplicable. Also, that the same applies for the sucking leech (c), which is feeding in the capillaries of its victim, while the undulations coursing along its tubular body from the mouth-cavity are analogous with deglutition, of which it is archetypal, the principle in mechanics being the same for both, while the structures are fundamentally the same, of which more anon. Finally, that pressure is transmitted through the body upon all the organs is also of easy demonstration. Notably the in- strument of Dulafoy for aspirating depots of pus and collections in the deep tissues and organs of the body, furnishes a crucial test of this circumstance. For example, it establishes the im- portant fact that an empty air-tight vessel when placed at the bedside of a patient, and made to communicate with an internal collection by means of an elastic tube and canula, will aspirate the collections the moment that pressure is reduced within the instrument by pumping out some of the air it contains, till the very last portions are removed. Furthermore, that it will do this at a distance from the body; this in the absence of any other means for assisting it through the tubing, the difference in pressure in the two localities being sufficient for the purpose. The practical deduction to be made from this circumstance is, that the extensive arrangements which obtain for reducing pressure in the lungs during inspiration should have the effect of aspirating the venous system at the same time that it aspi- rates air, while the action in the heart should greatly expedite it, whereby correspondence is produced between the circula- tion of air and blood in the alveoli, as before remarked. It is needless to extend the matter. In conclusion, the power of producing the rhythmical expan- sions and contractions for effecting the requisite changes in pressure in the organs and tissues for expediting circulation and producing the voluntary movements (the principle is the same in both) inheres in protoplasm itself, which expands and contracts with great facility ; moreover, expan- sion and contraction are correlated forces in Nature. The molecular action it involves will come up at the proper time and place. (See closing chapter.) Hoping we have made our- CONCLUSION OF PEINCIPLES. 45 selves understood sufficiently, let us now turn our attention to the circumstances in development explanatory of this funda- mental principle in the mechanics of circulation, taking the vital phenemena, anatomical and physiological, as the text, and the law of pressure underlying the organism as the key for construing and interpreting them, or as means to ends simply. And since there is increasing differentiation in the organs and tissues with progress in development, for the sake of simplicity and effectiveness, it were best to begin with the lowest organisms, taking the action in undifferentiated proto- plasm itself as the first visible expression, proceeding thence as rapidly as possible till the highest forms are reached. Indeed, one must proceed from the simpler to the more com- plex forms in order to make the latter intelligible. In this manner the whole is illuminated, and everything made plain and easily understood. CHAPTER IV. RESPIRATION IN DIFFERENT STAGES IN DEVELOPMENT. Import of Amoebae Movement — The Alternate Extension and Retraction of the Branched ' Processes, a Pumping Action for Increasing Circulation — Why Locomotion Should Increase Circulation Correspondingly — The Pumping Movements Analogous with Respiration — The Action in Vacuoles and the Radiating Canals, an Early Indication of the Mechanical Principle in the Heart and Arteries, the Latter Expanding as the Former is Contracting, and vice versa — The Action in Gastrula — Necessity for Co- ordinating the Mucous with the Skin-Surface, in Order to Produce Afflux and Efflux of the Fluids in the Body-Interior— This Circumstance Further Illustrated in the Worms for Producing the Undulations which Course Along the Body During Imbibition — The Principle Applied to Respiration and the Action Taking Place in the Lungs — Illustrated in the Frog, in which it is Demonstrated Experimentally that the Lungs Expand and Contract Regularly and Rhythmically Synchronous with the Action Taking Place in the Muscular Envelope or Containing Walls, in Order to Produce Afflux and Efflux of Air and Blood in these Organs for Respira- tory Purposes ; Otherwise Impossible — The Manner the Parts are Coordinated — Dependence of the Portal Circulation upon Respiration— The Same Principle in Mechanics for Every Stage in Development— The Action in Birds— The Special Adjustments in the Viscera— Portal Circulation in. This relation which animal life sustains to pressure, and the law for increasing circulation by rapid rhythmical changes in £>ressure, would afford a ready explanation for the alternate extension and retraction of the branched processes in amoebae, and which function as temporary villi for pumping the com- merce in the organism. For example, when an amoeba is placed upon the slide in the field of the microscope, and a drop of water suffered to fall upon it, it at once begins to extend and retract the branched processes in rapid succession, and in every direction from the undifferentiated body, appear- ing and disappearing, now here, now there, in the protoplasmic substance. It is not trying to get away, but trying rather to live and sustain existence by means of these branched pro- cesses and this pumping action thus set up in them. In short, the animal is simply feeding ; nay, feeding and respiring at the same time, the one involving the other ; and which PUMPING ACTION IN AM(EB^E. 47 should be the case for maintaining a balance in force, the same principle for generating force applying for it as for the higher stages in development, and must necessarily apply for every stage. These so-called pseudopodia (false feet), then, are not for effecting locomotion simply, as their name implies, but for sustaining existence ; at the same time, they are available for locomotion, though this is laboriously and indifferently per- formed. Furthermore, it is readily perceived that this also should increase circulation correspondingly, since it involves more extended and energetic action in the branched processes for effecting it, whereby the requisite force is generated for producing this action ; otherwise impossible. In this manner a balance is maintained, one adjustment involving the other. In fine, when the amoeba extends a branched process, it develops a lower pressure within itself than exists externally, when the fluids immediately adjacent rush into the low- pressure area until pressure is uniform, and which corresponds with inspiration. But when the branched processes are retracted, this compels the contents into the body -interior, at the same time expelling waste products, and which corre- sponds with expiration. Of course, the more rapid the action the more rapid is this circulation. The in-going current con- tains the nutritive and force -producing elements, and the out- going the waste products ; while water is the vehicle or medium of transportation for the commerce, at the same time it enters into the molecular arrangements for forming the structure itself. In addition, water is a powerful stimulus for exciting the pumping actions and arousing latent energy, so that the moment it touches the amoebae it begins to pump, and thus compelling it into itself, the whole mechanism becomes "alive." But remove the water, and the pumping action stops and life is in abeyance. No one can tell what water is — extend- ing as it does into the depths of force — further than to speak of some of its performances and the conditions which deter- mine them, notably the polar actions and the means of ener- gizing them, inclusive of the law of pressure for increasing the action in the manner spoken of, or by rhythmical changes in pressure for compelling it in and through the organism in the 48 PUMPING ACTION IN AMCEB^E. measure of the requirements. Furthermore, by extending and retracting the branched processes from different portions of the body-surface, the amoeba is enabled to effect a short and direct journey of the fluids to the portions where they are most needed, and which subserves the purpose of a vascular system for effecting the same ends in the higher stages in development ; at the same time, it also involves an amount of motion of the fluids loitliin the body, whereby metabolism is expedited. Thus, when a branch process is being extended, the low pressure which is thereby developed within this por- tion produces afflux of the fluids in two directions — one from the body itself, the other from the environment — coming from opposite directions simultaneously to the low-pressure area till pressure is uniform ; while in the body itself a special force applies for increasing the action, notably the contraction which sets in simultaneously with extension in the branched process, should effect a corresponding increase in pressure for compelling the contents into the branched process, the body fluids flowing into this more rapidly in consequence. On the other hand, when the process is being retracted there is commensurate expansion in the body in order to effect it, the former producing high, the latter low pressure ; hence, the fluids must flow, out of the branched process into the body- interior with corresponding energy. Thus, a churning move- ment is produced in the fluids for hastening metabolism. The following forcible illustration by the distinguished biologist at Heidelberg (Fig. 7, A, B) will serve for impressing the mat- ter. It represents an amoeba at two different moments during movement. By fixing the eye upon the food particle, we can very readily perceive how the contents are affected by the pumping action in the processes. Thus, in the case of B, in which a branched process is extended, the body is narrow or contracted, while the food particle is moved down to the root of the process ; but in A, in which the process is retracted, the body is considerably widened or expanded, and now the food particle (/) is moved up to near the central portions of the body. Thus, a to-and-fro movement is established be- tween the fluids in the body and the branched processes, thereby effecting more rapid disintegration and assimilation THE INCREASE OF RESPIRATION AND CIRCULATION. 49 of the food, at the same time that it pumps the fluids in and out of the body for respiratory purposes, inclusive of the nutritive elements in a state of solution Hence the rapid absorption of tine coloring matter, which passes into the amoeba with great rapidity. Finally, that this pumping action in amoeba relates to the nutritive and functional processes is sufficiently obvious, there being no other means for increasing circulation. Moreover, the same action is seen in Bathybius — enormous masses of retiform protoplasmic substance covering the floor of the ocean, in places to many feet in depth — which does not loco- mote nevertheless performs similar movements when a frag- ment is placed in the field of the microscope, and a drop of water is suffered to fall upon it, the action undoubtedly indicat- ing respiratory movement for increasing circulation in the Fig. 9. — An Amoeba figured at two different moments during movement ; n, nucleus , i, ingested food. Some vacuoles may also be noted. — Gegenbaur. protoplasmic substance and interstices, the surrounding fluids flowing in and out through these. Modes of Introducing Solid Food in Amosbce. — The me- chanical principle which applies for absorbing solid food in amoebae is the same as for producing the pumping actions, notably by expanding and contracting upon it, only it has different expression, and which varies with the stage in development. Thus, in the lowest amoebae, in which the body- surface is naked and undifferentiated protoplasm, solid food is absorbed in two different ways : either by extending branched processes around the solid particle, when the soft substance flows together again, and so engulfing it ; or else by the body itself opening at the point of contact for receiving it, the food at 50 INTRODUCTION OF SOLID FOOD. the same time sinking into it from the action of external press- ure till fully submerged, when the substance closes over it. In either case involving expansile and contractile action in the protoplasm in order to effect it ; while this in turn is referable to the action in the molecules, and which, of course, is regu- lated as occasion may require. And any portion of the body-surface may thus function as a mouth or receiving organ for the food, just as any portion may serve for extending and retracting the branched processes for pumping in the fluids, while pressure applies alike to both actions for making them effective. Thus, when the surface opens in response to the stimulus of the food brought into contact with it, a suction force is at once produced for compelling it into the organism, and which necessarily results from the act of expansion, the particle sinking deeper and deeper with progress in expansion, till finally it reaches the locality where it is to undergo diges- tion and assimilation, there being no stomach or digestive cavity for receiving it when the protoplasmic substance closes over it. Likewise, when a cortical layer and external organs are differentiated (Fig. 10), the same principle applies. In this case the radiating processes (e) serve as tactile and prehensile organs for directing the food to the part which is to function at the time as a mouth or receiving organ, holding it against the surface (a) till the requisite changes can be made in the adjacent parts, when it is compelled into the body under the action of external pressure, where their function ends in this respect. And let it not be thought for a single moment even that they can compel the food into the body, for this rude mechanics is not only wrong in principle, but must inevitably prove disastrous, since the action necessarily involves appro- priate internal arrangements for receiving the food, while the parts yield of their own accord under the stimulus of the food, a change at once setting in at the point of contact, and extending thence to the adjacent protoplasm, which in like manner recedes before it till it reaches its destination, all the parts acting in harmonious concert to this end. In other words, room is made for the food as it progresses into the body, while the very effort to make this room in- vokes the force of external pressure for compelling it into INTRODUCTION OF SOLID FOOD. 51 the body. And from the moment it starts upon the journey till it reaches its destination, such is the case. And one morsel after another being thus taken in, when the amoeba is made to eat, the limit in expansion is finally reached when no more food can be taken into the body, a circumstance, indeed, which is forcibly illustrated in a higher stage in development, e. g. , the gorged leech (Pig. 17). But we will not anticipate. When there is a mouth, however (Ciliata), this is expanded when brought in contact with the food, pressure, of course, forcing it in simultaneously, whence it passes into the soft parenchyma as previously, as there is no enteric tube for con- veying the food masses, the parts again contracting and closing over it. Indeed, the powers of expansion possessed by these low organisms is something extraordinary, some of the more ravenous infusoria, for example, actually swallowing other Fig. 10.— Actinosphserum (Gegenbaur). a, A morsel which has been taken in as food, and just pushed into the soft cortical layer b, by a change in pressure ; c, central parenchyma ; d, other food which had previously been thus introduced ; e, pseudo- podia of the cortical layer. infusoria nearly as large as themselves. The mouth being brought in contact with the prey, is suddenly expanded upon it, which at once develops a suction force for compelling it into the cavity, when the mouth contracts again for completing the act. Other infusoria (Suctoria) possess hollow radiate processes (Fig. 11, p. 55), which pass through the envelope of the body and function as suckers, so to speak, and which are made to penetrate the body of other infusoria for aspirating the fluids into themselves, flowing into them in the form of drops, thus feeding upon the juices of the victim simply, not possessing a mouth. But for aspirating the fluids, of course 52 CARDIAC ACTION IN VACUOLES. the body must expand for reducing pressure, the fluids in consequence flowing into themselves from the body of the victim where pressure is higher. Finally, since there is no means for compelling food into the body save by changes in pressure, it follows that but for this power of expanding and contracting, which inheres in proto- plasm, that the food must inevitably remain out of the body, for in no other way could the requisite changes in pressure be produced. In fine, that animal life would be impossible. The Action in Vacuoles and Wliat it Involves. — The hol- low cavitary spaces filled with a colorless fluid and known as vacuoles (Fig. 11, v, v), is the first foreshadowing of a spe- cialized vascular apparatus for distributing the fluids through the body, while the phenomena manifested- in them possess special significance with reference to the principle that obtains in the heart and arteries. Thus, the vacuole expands and contracts regularly and rhythmically like the diastole and systole in the heart, while a system of radiating canals (at present invisible) receive and discharge the fluids from the pulsating vacuole, expanding and contracting alternately with it, so that during systole in the vacuole there is diastole in the radiating canals, and vice versa ; the vacuole itself, like the radiating canals, coming into view during diastole, from the presence of the fluids, which give it definition, and dis- appearing again with systole when the fluids are in the radi- ating canals, the two alternately appearing and disappearing in this manner and in regular order and succession, while the fluids flow from high to low pressure in conformity with uni- versal law. The following lengthy excerpt, however, will place the matter fully before the reader : * k ' More definite respiratory arrangements are seen when, as in many protozoa, water is taken into the body. Cavities, which are filled with a fluid, and which gradually contract and com- pletely empty themselves, after having reached their maxi- mum of distension, appear within the protoplasm ; when empty they seem to disappear. These vacuoles, like the vacuoles in the cells of certain tissues, are partly variable structures, now * Elements of Comparative Anatomy, pp. 85. 86— Gegenbaur. PRIMITIVE CIRCULATION. 53 appearing and now disappearing, and partly constant. When they are constant, their function is increased, and they often expand and contract regularly and rhythmically, like the car- diac systole and diastole. Contractile vesicles of this kind are often seen in the amoebae (Difflugia and Arcella), and are very common among the infusoria. They are also known as vacu- oles. The fluid which collects in the vesicles is drawn from the parenchyma of the body and is ieturned to it, or passed out to the exterior on the contraction of the vesicle Fine communications with the exterior have been made out, so that the latter course is the probable one ; but we need not, on this account, conclude that water does not enter by the same passage. ' k In the infusoria the vesicles lie in the cortical layer, generally just under the delicate cuticle, and at definite points. If only one vesicle is present, it lies either anteriorly or posteriorly ; if two, there is one near each end of the body. Trachelius ovum is remarkable for a large number of small vesicles. No special membranes can be made out on the wall of the vesicle nor in the canals which pass off from it. Like the vesicle, the canals can only be made out while they are filling. The vesicle and canals contract alternately. In Paramecium the canals enlarge at the commencement of the systole and approach one another as the vesicle diminishes in size, so that they form a stellate figure at the moment when its systole is most complete and the vesicle has disappeared. While the vesicle is filling, the canals look like small diverticula on it, and are not again fully distended until the diastole is complete. The number of the canals, which is limited in P. aurelia to eight or ten, is increased to thirty in Bursaria flava, and is much higher in Cystostomum leucas. In these forms the canals have a wave- like course, and ramify at their extremities Canalicular tracts are formed by the fusion of several spaces filled with water into longer tracts, as in Stylonychia (St. mytilus), and they empty themselves into the contractile vesicle by definite passages. The long canals of Spirostomum ambiguum, which are also visible for a time only, but which are longer than these, are like them, so that we can make out a continuous series from the first appearance of an apparently indifferent 51 ACTION IN THE HEART AND ARTERIES FORESHADOWED. cavity to a definitely arranged system of tubes." Italics are added. There can be no doubt, then, that the func- tion of vacuoles relates to the distribution of the fluids through the body, and which involves not only respiration and expulsion of waste products, but the nutritive proc- esses as well, the fluids containing both nutritive and force- producing elements. But the point we wish to make, how- ever, concerns the mechanical principle which applies for filling and emptying the vacuole and radiating canals, and which is undoubtedly rhythmical changes in pressure. Thus when the vacuole expands it develops a lower pressure within itself than exists externally : hence the fluids from the adjacent parenchyma and environment (Fig. 11, v, v.) flow into the low-pressure area till pressure is uniform ; but when contraction sets in, the high pressure which this develops within the vacuole causes them to flow out again, passing thence into the radiating canals, which expand simultaneously for reducing pressure and so obviating reflux ; thence into the environment during contraction and development of high pressure in the latter. And so by alternate expansions and contractions in the vacuole and radiating canals, the fluids are pumped through the body for respiratory purposes ; other- wise is meaningless. In short, it represents a suction and a driving force, acting alternately ; the one produced by diastole, the other by systole. The eminent anatomist and naturalist would seem to emphasize systole, but the fluids would first have to be gotten into the vesicle by diastole, and the development of low pressure which this produces, before one may speak of systole for driving them out again ; the one necessarily involving the other. But exclude press- ure and the power of producing rhythmical changes in press- ure, and these actions would be meaningless. Now, then, principles do not and cannot change ; hence this law for increasing circulation remains the same for every stage in development. And in this primitive circulation, in which not so much as a living membrane is made out, either in the vacu- ole itself or the radiating canals, which are wrought, as it were, in naked and undifferentiated protoplasm, the principle in the heart and arteries is clearly indicated ; the one expand- ACTION IN THE HEAET AND AKTEEIES FORESHADOWED. 55 ing as the other is contracting, and vice versa; while the valves serve for obviating reflux ; and leaving not the shadow of a doubt upon the mind of the power in Nature to effect these adjustments. But when we come to the blood-vascular system, how- ever, ample proof will be furnished of this circumstance. Suffice it to say, the law applies everywhere. And the more one reflects over this circumstance, the more wonderful it grows. This will serve for illustration. And we will now carry the matter a little further, pushing the law in the organ- ism to its logical results. Eig. 11. — An Acineta, with part of its stalk (Gegenbaur) ; p, pseudopodia-like, but stiff, tentacles ; v, vacuoles ; n, nucleus ; e, aciliated young form lying in the so-called broad cavity. — G-egenbaur. The Action in Gastrula. — This brings us to the next stage in development, or the primitive compound organism (Fig. 12), from which in due time the higher organisms are evolved by the processes of growth and differentiation. Here the cell- colony is first grouped in two separate and distinct layers, forming the walls of the little animal (B), the one constituting the internal layer, or entoderm (i), the other the skin-layer, or exoderm (e); while the fluids flow in and out of the little stomachal cavity thus formed through the oral orifice (o) dur- ing the rhythmical expansions and contractions taking place in it. Flowing in, of course, during expansion and the devel- 56 ACTION IN GASTRULA. opment of low pressure which this produces till pressure is uniform, and flowing out again by reflux action through the route of ingress during contraction and the development of high pressure which this produces to equalize pressure ; in this manner readily producing afflux and efflux of the fluids in the stomachal cavity : while the changes of form which this in- volves in the individual cells, in order to produce these actions should increase circulation in them correspondingly, and which the scheme calls for in order to generate the force which is expended in these actions, the one involving the other. .All of Fig. 12— Gastrula of a Chalk-sponge (Olynthus). A, from the outside ; B, in longi- tudinal section through the axis ; g, primitive intestine ; o, primitive mouth ; i, intestinal-layer, or entoderm ; e, skin-layer, or exoderm. — Haeckel. which is plain enough. But the circumstance in which interest culminates is the one of coordination in the cell-colony, so as to compel the two layers to expand and contract simultaneously, in order to swallow the food and effect the pumping action for producing afflux and efflux of the fluids in the primitive intestine (g) ; otherwise impossible. In short, the inner layer (/) or intestine expands and contracts snychronously with the outer wall or skin-layer (e), which answers to the muscular envelope in the body- walls in the more advanced stages in development, the two acting in harmonious concert to this end, as is the case in the later stages ; only there is no nervous apparatus for effecting coordination, the walls expand- COORDINATION OF INTERNAL AND EXTERNAL PARTS. 57 Ing and contracting of their own accord under the stimnlus of the fluids in which the little animal swims and sustains exist- ence. The intimate relations the walls sustain to each other enable this to be done, as the inter-molecular action in the two cell-layers could thus be connected for producing uni- formity throughout. But with progress in development, how- ever, the layers become more and more differentiated and separated from each other ; consequently, other modes for effect- ing coordination must be had recourse to ; hence the nervous apparatus which is developed and differentiated with progress in development for coordinating the structures and unifying the molecular actions, to the end that a balance in force may be maintained, and which cannot be done unless the mechanics is made to connect through and through. It is comprehensive, but easily understood. J n this archetypal form, then, we have early indication of the principle in the mechanics. Indeed, the very existence of this law of pressure in the organism is sufficient in itself to establish that circumstance, now that attention is directed to it. But a few pointed exam- ples will serve for impressing the matter. Leaving the Gastrula, then, we take up the case in the "Worms, in which development is considerably advanced. Here the external layer (exoderm) is differentiated into a dermo-muscular layer, and the internal (entoderm) into the intestine (Fig. 1 3, A, B, m, v) ; but are still more or less inti- mately connected by means of connective tissue fibres running from one to the other, a coelon or visceral cavity not yet be- ing differentiated, the vestiges only presenting in rudimentary spaces adjacent to the intestine, in which the fluids collect and pass into the vascular system. For producing and coordinat- ing the movements in the two surfaces, and maintaining uni- formity, we have a double ganglionic chain of nerves extend- ing along the ventral surface from the cephalic to the caudal end (Fig. 14), each ganglion serving as a separate centre of nervous force for producing the movements in the contiguous parts into which the nerves are distributed, so that reflex action is readily excited. in them by means of sensory impres- sions propagated from the mucous surface by the stimulus of the food, without involving other portions, and which is neces- 58 COORDINATION OF INTERNAL AND EXTERNAL PARTS. sary in order to produce the undulations passing along the body of the worms during imbibition and the passage of food along the canal ; at the same time, the whole are readily co- ordinated by means of the nervous links or commissures extending from ganglion to ganglion for connecting them with each other and with the encephalon (Fig. 14) for producing the voluntary movements and maintaining a balance in the organ- ism. There is considerable complexity, arising from the neces- sity of maintaining the local actions in correspondence with the physiological requirements, but the principle underlying it all is readily apprehended. Now, then, in order to produce the undulations which course along the body of the worms during imbibition, and which answer to the passage of the food along the intestinal canal, Fig. 13. — Transverse section of Asoaris Luinbricoides, A, and of Hirudo, B. c, Cuticular layer ; to, muscular layer ; r, lateral line, with the excretory organ ; p p, upper and lower median line : p1, oblique fibres ; v, enteron ; d, dorsal ; I, lateral vascular trunk ; s, vesicle of the excretory organ ; n, ventral nerve-chord. — Gegenbaur. doth of these layers must expand and contract together and simultaneously, as in gastrula, for pumping the fluids into and out of the cavity of the intestine ; only that in the present case this has been prolonged into a canal, but for obvious reasons the principle is maintained, since the whole relates to pressure and the power of producing rapid rhythmical changes in pressure. In fine, the worms may be likened to a string of gastrulse with the ends merged in each other, while the fluids are passed from one to the other by means of rhythmical expansions and contractions till the terminal end is reached, COORDINATION OF INTERNAL AND EXTERNAL PARTS. 59 every pair of nervous ganglia, with, the nerves extending thence into the adjacent structures, representing one of these enlarged gastrula-territories. In point of fact, however, a single gastrula had formed the basis of it all, the structures being gradually elaborated from this with progress in development ; but it will serve the purpose of illustration. But the same mechanical principle applies for producing afflux and efflux of the fluids in the intestine of the worms as in the primitive intestine of the gastrula ; only, in place of escaping through the oral orifice by reflux action during contraction, it is passed onward into the next adjacent gastrula territory, which expands simulta- neously for reducing pressure in order to compel it in this direction ; otherwise, it would escape through the oral orifice by reflux action as in gastrula. And thus, by producing areas of low and high pressures contiguous to each other, a dual force applies in the worms for increasing the action in the fluids, at Pig. 14. — Nervous System of the Leech (Owen) ; a, anterior cerebral ganglia ; b b, the 10 ocelli arranged around the margin of the upper lip ; c, posterior cerebral ganglia. the same time compelling them to move onward in the canal, and flowing always from high to low pressure in conformity with universal law : the one acting as a pulling, the other as a pushing-force upon the food, acting simultaneously. This, then, is the explanation for the undulations which pass along the body of the worms during ingestion, indicating the passage of the food along the canal of the intestine, as before remarked. Nothing could be more simple or more effective. The principle is not new either, but old — old as Nature ! Only it had not been applied to the animal body for elucidating the vital phenomena ; as though the body could be outside and independent of this fundamental force in Nature for con- trolling the movement of the fluids upon which the very body itself is based. 60 COORDINATION OF INTERNAL AND EXTERNAL PAUTS. One other circumstance, of great importance in this connec- tion, remains for mention, namely : The Progressive Increase in Size with Ingestion. — As there is no unoccupied space in the body, it follows there must be corresponding increase in size with ingestion, a circumstance which also has forcible illustration in the worms (Figs. 15, 16, 17); the gorged leech, for example (Fig. 17), being several times the natural size in the empty condition (Fig. 15). This is all brought about gradually, the waves of expansion pass- ing from the mouth-cavity along the body of the sucking Pig. 15. Fig. 16. Fig. 17. Three cute of the Leech, showing the appearance before imbibition, during imbibition, and after imbibition. Fig. 15. — Appearance before imbibition. Fig. 16. — Appearance during imbibition ; I, oral sucker, expanded ; 2, wave of expan- sion passing along the body to the hinder portions ; 3, where they are added up in the general expansion which takes place. Fig. 17. — Appearance after imbibition, and when the animal is fully gorged with blood and further expansion is impossible. leech (Fig. 16, 1, 2), being merged in the general expansion (3) which results. In other words, room is made for the food as it progresses in the body ; otherwise the balance in pressure could not be maintained, and the food would regurgitate. And this thing continues till the limit in expansion is reached, when no more food can be taken (Fig. 17). And but for the fact that the internal and external parts are in correspondence, how otherwise could this action be pro- duced % Thus, the stomach, which extends nearly the whole THE PRINCIPLE APPLIED TO RESPLEATION. 61 length of the body, is not forcibly pulled open by the action in the muscular envelope, but expands of its own accord in harmonious concert with the muscular envelope ; while for effecting this action in the walls, as also for producing the local actions, is the office of the double ganglionic chain of nerves upon the ventral surface, with the nerves extending thence into the parts, whereby the utmost concert of action is produced, so that not only the requisite changes in pressure for swallow- ing the food may be readily effected, but at the same time a. general expansion in the body commensurate with the food ingested, for maintaining a balance in pressure, may also be produced — the one involving the other ; as the requisite room- must be made in the body as fast as the food is taken in, in order to maintain a balance in pressure ; otherwise impos- sible. All of which is plain enough and easily understood. Of course, as the food is removed by the absorptive processes, the intestine contracts correspondingly, while the fullness in the vessels which this produces effects corresponding expan- sion in tliem, for which a special physiological adjustment obtains in the organism, the whole being regulated by nervous force, to be spoken of further on. We are now prepared to take another important step in the physiological adjustments, notably : The Action in the Lungs. — This necessity for maintaining' correspondence between the internal and external surfaces, in order to produce afflux and efflux of the fluids in the body- interior, must now be applied to the mechanics for producing afflux and efflux of air and blood in the lungs for respiratory purposes, the principle being the same In a word, the lungs and containing walls expand and contract simultaneously, as be- fore remarked, and which is not only true logically, but it also admits of actual demonstration. For this purpose selection is made of the frog, which has neither diaphragm nor ribs for assisting the action in the lungs, the ribs remaining in an undeveloped and rudi- mentary condition (Fig. 18) ; and the lungs being contained in the common visceral cavity, offer exceptional advantages for studying respiration, which is thus, so to speak, ex- G2 THE PRINCIPLE APPLIED TO RESPIRATION. posed and laid bare. It is the common impression among physiologists and naturalists that the frog respires by pump- ing the air in and out of the lungs by means of the throat-ap- paratus, but which is only partially true, the arrangement in the throat serving to assist it simply ; and that it is not the fundamental circumstance in batrachian respiration, 1 have fully proven by excising a portion of the floor of the mouth, so as to lay the cavity open and effectually destroy it as a pumping apparatus for pumpirig air into the lungs : notwith- standing this, however, the animal continued to respire, ulti- mately recovering from the wound, which closed by cicatriza- tion in the course of two weeks. The immediate effect of the Fig. 18.— Skeleton of the Frog.— Owen. operation was very characteristic, the body suddenly col- lapsiug like a pricked balloon over the whole lung-region (Fig. 19), the spine and the stumps of the undeveloped ribs standing out in great prominence, produced by the soft tissues upon the sides being forcibly compressed under them, impart- ing an excavated appearance to the lateral regions ; while the abdominal portions (2) appeared round, full and pendulous from compression of the envelope around them, making them also stand out prominent. The collapse was so sud- den and unexpected as to startle me. Fully expecting him to die outright, which I thought a matter of course, and saying to myself, "I am not going to prove anything by you," I dropped him into a waste-bucket containing a thin THE PRINCIPLE APPLIED TO RESPIRATION. 63 stratum of water and some loose, wet paper; and the night being far advanced, I at once sought my couch, deeming the experiment over and done with. The following morn- ing, however, upon glancing into the bucket, the animal, to my unspeakable amazement, was sitting up, fully expanded, head high, and looking at me out of his great luminous eyes, as natural to all appearances as ever, save the wound in his throat (Fig. 20). That thin stratum of water in the bucket, together with the loose wet paper, under which he could creep to keep himself moist, were the best possible conditions for promoting recovery after the operation, though I was not conscious of this at the time when I threw him into it with a Fig. 19. Fig. 30. Two cuts of the Frog, showing the collapsed condition of the body produced by destruc- tion of the throat-apparatus, and the subsequent expansion which takes place. Fig. 19. — Appearance after destruction of the throat-apparatus ; 1, 1, outline of the undeveloped ribs ; 3, abdominal viscera ; 3, opening in the floor of the mouth. Fig. 20. — The Frog expanded to its normal size, notwithstanding the opening in the floor of the mouth. feeling of sore disappointment at my heart over the untoward result of an experiment from which I had expected so much, and, as I thought, reasoned out so carefully. And, after all, there he was, fully alive, and on the qui vive, too, as though expecting me But other surprises were in store for me, if possible of a still more agreeable nature. Thus, I found while the throat-apparatus continued to move to and fro, the wound alternately widely gaping and contracting, but still leaving a considerable opening, at the rate of 120 to 130 per minute, that another much larger and slower movement was pervading the body itself, from 20 to 30 times per minute. And that this 64 THE PRINCIPLE APPLIED TO RESPIRATION. was the true respiratory movement was proven by the fact that it corresponded with the action in the alee nasi, which ex- panded and contracted synchronously, as is the case in impeded respiration, and which at once stamps its true character. The destruction of the throat-apparatus and the embarrassment to respiration which this produces, brings into prominence the action in the lungs and containing walls, espe- cially in the lateral dorsal regions, where it is conspicuous. In times of excitement, both movements are increased, but the relative frequency is maintained; showing that they are also connected. Upon taking him up, however, he struggled violently in my hands and again collapsed, presenting in all respects the same appearances as at first. But replacing him at once in the bucket, he filled himself out again with air as before. Of course, the action is necessarily comparatively slow, from the abseuce of " ribs" and special muscles for assisting the lungs by the leverage they afford for reducing pressure ; still, he accomplishes it, nevertheless, filling the lungs completely and restoring the natural rotundity (Fig. 20). Moreover, he seemed to acquire more power in the larynx for holding the air, not collapsing so readily as at first, an amount of compen- sation for the injured throat-apparatus taking place in this way. Eight days after the operation, in exhibiting him to Dr. G unth er, the distinguished naturalist of the British Museum, and others, and holding him firmly by the hind legs for the purpose, by a sudden and energetic movement leaped out of my hands, and falling with great impact against the floor, again collapsed as previously. It produced a sensation. The wound had contracted considerably, but the top of the larynx was easily visible through the opening. A week subsequently, however, it had closed entirely, and the old condition was com- pletely restored. But there was some deformity in the throat from loss of substance and contraction of the wound, bring- ing the contour of the larynx into prominence, and showing something like an Adam's apple. But he was thoroughly recovered, hale and hearty, and swam with greatest eager- ness in the tank when placed with the other frogs at the shop where I obtained him. THE PRINCIPLE APPLIED TO RESPIRATION. 05 It is scarcely necessary to add that the results of this opera- tion prove incontrovertibly that the lungs expand synchro- nously with the containing walls ; otherwise it were utterly im- possible for the animal to have inflated them or filled them with air, having neither diaphragm nor "ribs," nor a throat- apparatus for compelling air into the lungs. And since air flows from high to low pressure, it follows that the lungs must expand in order to produce afflux of air in the organs ; other- wise impossible. But, then, might not expansion in the muscular envelope itself effect it ? No ; this should produce low pressure in the vi3ceral cavity, and thereby speedily bringing life to an end by causing afflux of the fluids in the cavity, and arresting the functions in the lungs. In short, the low pressure must be made within the lungs themselves in order to produce afflux and efflux of air and blood in the organs for respiratory purposes, at the same time keeping them in their respective channels ; otherwise impossible At any rate, however, the muscular envelope expands ; and if this expands, there is no reason on earth why the lungs may not do likewise — nay, must do so in the very nature of things, the law compelling this circumstance. Explanation for the Sudden Collapse of the Body- Walls. — In batrachians the tongue is applied to the posterior nares in the form of a valve, which converts the mouth-cavity into an air-tight chamber and enables the pumping movements to be made in the throat for assisting respiration, at the same time it prevents escape of the air when rude force is applied, as when the animal leaps ; the absence of ' ' ribs' ' for imparting solidity and firmness to the walls rendering this necessary. Hence, when the air chamber is destroyed, the animal strug- gling, collapse is inevitable, the larynx itself not being sufficient for the purpose. It subserves other important uses also. Thus it enables the animal to remain for considerable periods under the water, by pumping the air to and fro, or backward and forward, between the chamber and the lungs, till fully exhausted of its oxygen, when it returns to the surface for more ; the air being, so to speak, bottled up during this time. Chelonia and crocodilia all possess this power ; so also ceta- cea ; the enormous chambers forming the tortuous nasal pass- 06 MODE OF COORDINATING THE LUNGS AND BODY-WALLS. ages in the latter, which are closed externally by means of a plug projected from the side, subserving this purpose and enabling the animals to disappear for long periods beneath the surface In the seal the external nares are closed by powerful muscles, which are promptly contracted at the moment of disappear- ance. Other animals are similarly endowed. Being air- breathers, the air must be thus forcibly retained during the time of submergence ; otherwise they could not live. Mode of Effecting Coordination. — The mode the lungs are coordinated with the muscular envelope or containing walls, together with the changes and mode of distribution of the nerves to the parts, is also easily explained, in the worms, for example, we have seen that coordination of the in- ternal and external parts forming the enteron and muscular envelope or containing walls, is effected by means of a double chain of nervous ganglia extending along the ventral surface, whence the nerves, which are given off laterally, also symmet- rically (Fig. 14) proceed directly into the adjacent structures, passing from one to the other, the intimate relations they sus- tain to each other enabling this to be very readily done ; but with progress in development and the differentiation of a visceral cavity, however, which is necessary for increasing the action in the viscera in connection with the special functions, it is manifest that this calls for fresh arrangement in the nerves for coordinating the viscera with the muscular envelope and containing walls, since they are now completely separated. Hence, the pneumogastric nerves which are sent down from above for connecting the viscera with the medulla oblongata (Fig. 21) ;* and being correlated with the spinal nerves to the external parts, concert of action is readily produced, so that the whole performs as but a single organ only for pump- ing aii* and blood through the alveoli for respiratory purposes. And in the later stages in development, when a diaphragm comes into the scheme for separating the viscera in the abdo- men from the viscera in the chest, likewise the phrenic nerves (Fig. 91, F) for coordinating this portion with the external parts, so that the utmost harmony is produced throughout, * For the purpose of illustration simply being fundamentally the same as in the frog. MODE OF COORDINATING THE LUNGS AND BODY-WALLS 67 the correlation of all these nerves in the medulla oblongata enabling this to be very readily done. There is increasing complexity, but the principle in the mechanics furnishes a key for easily unraveling the structures, which are means to ends simply. The existence of the pneumogastric nerves, then, is readily accounted for. The role they perform in the Fig. 31. — Left Pneumogastric Nerve, in diagram (Dalian). 1, pharyngeal branch ; 2, superior laryngeal ; 3, inferior or recurrent laryngeal nerve ; 4, pulmonary branches ; 5, 6, stomach, liver, etc. viscera in the abdomen will come up later, but its importance would be difficult to overestimate. In the fishes we have the analogue of this in the opercula and branchia, together with the branches of the 8th pair (Fig. 166) for setting up the pumping actions for producing afflux and efflux of the water 08 PORTAL CIRCULATION INCREASED BY RESPIRATION. and blood in these organs i'or r ■ spiratory purposes, while the other portions are continued on into the abdomen and the external muscular walls (Fig. 15S, o, 4) for coordinating them with the branchia and opercula, or the same as in the air- breather, the principle being the same. And so likewise down the whole chain in development to where a visceral cavity ceases to exist, similar arrangements obtain for co- ordinating the viscera with the muscular envelope appropriate to the stage in development and the requirements in respira- tion and circulation, in order to evolve the force expended in them. But for the sake of brevity, we pass over the details, the matter being so very obvious. Dependence of the Portal Circulation upon Respiration. — Finally, we have to mention a circumstance of deepest import in the mechanics of circulation, namely : The rhythmical com- pression of the viscera in the abdomen synchronous with respiration, and which is produced by respiration, for increas- ing the portal circulation correspondingly, and which it would be difficult to overestimate, since the portal circula- tion could not be carried on without it ; neither could a bal- ance be maintained in the absorptive and oxygenating proc- esses which the scheme calls for, and which requires the absorptive processes in the intestine and the portal circulation, to be connected with respiration in such manner that the effort to respire must necessarily increase the two correspondingly. It is easily apprehended. Thus, the muscular envelope form- ing the walls of the common visceral cavity functions as the Jloor of support to the viscera in the abdomen, which are everywhere in contact with them, gravitation compelling this circumstance (Figs. 19, 2 ; 25, U), hence are necessarily affected by every movement in the walls for effecting the changes of pressure in the lungs for producing afflux and efflux of air and blood in the organs for respiratory purposes, and which, of course, should increase the portal circulation correspondingly. It could not do otherwise, in the very nature of things. They are forcibly compressed during ex- piration for producing high pressure in the lungs, being com- pressed against them for this purpose, when the heart serves as a suction-force upon the portal blood, which thus flows PORTAL CIRCULATION INCREASED BY RESPIRATION. 69 from high to low pressure ; while during inspiration the suction-force in the lungs is added to this, which greatly increases the action by means of which the portal circula tion is readily carried on ; otherwise impossible. For show- ing the dependence of the portal circulation upon res- piration, the following physiological experiment possesses fresh interest, and is certainly very conclusive upon this matter : * ' ' Two frogs are slightly curarized and placed side by side in the supine position. In both, the heart and great vessels are exposed, as in the preceding section. It having been ascer- tained that the circulation is normal in each animal, and the frequency of the contractions having been noted, the brain and spinal cord are destroyed in one of the frogs, by inserting a strong needle into the spinal canal immediately below the occipital bone, and then passing it upward and downward. This may usually be accomplished without much loss of blood. If now the frog which has been deprived of its nervous centres is compared with the other, it is seen that in the former, although the heart is beating with perfect regularity and un- altered frequency, it is empty, and in consequence, instead of projecting from the opening in the anterior wall of the chest, it is withdrawn upward and backward toward the oesophagus. The emptiness of the heart is not limited to the ventricle and bulb. The auricles are alike deprived of blood ; and if the heart is drawn forward by the apex, it is seen that the sinus wnosus and vena cava inferior are in the same con- dition. The state is therefore not dependent upon any cause inherent in itself but on the fact that no blood is conveyed to it by the veins. To make this still more evident, the rest of the visceral cavity may be opened, when it is seen that although the vena cava is collapsed, the intestinal veins are distended." The distinguished physiologist and experimentalist, in cast- ing about for an explanation of the preceding phenomena, con- ceived the idea that the non-arrival of the blood in the heart was due to relaxation or expansion of the arterial system from vaso-motor paralysis ; and while this undoubtedly was a factor * Hand-book for the Physiological Laboratory. — Burdon-Sartderson. 70 POKTAL CIRCULATION INCREASED BY RESPIRATION. in the case, it would certainly not account for a portion of the phenomena — notably, the turgescence in the portal vessels. If loss of tension in the arterial system produced emptiness in the lower cava-system then, how could it produce the oppo- site condition of turgescence in the adjacent portal system % If true in the one, it should be true in the other also. We take it, however, that suspension of respiration was the principal cause of the phenomena, for the reason that it arrested the pumping action in the lungs for aspirating the systemic capil- laries, and the rhythmical compression of the viscera in the abdomen, which this produces for increasing the portal circu- lation. The extent and firmness of the liver-structure, the character of the portal vessels, and the firm adhesion of the walls of the hepatic veins to the liver- substance for maintaining patency, all tend to show this circumstance. And since there is no other means for increasing circulation but by rhythmical changes in pressure, it follows that the liver must be rhythmically com- pressed for increasing circulation in it. Moreover, it should be borne in mind that the portal vessels are sandwiched, so to speak, between two extensive capillary systems : one in the intestines, in relation with the mucosa ; the other in the liver- substance. Hence the necessity for this direct application of force for increasing circulation in the liver and portal vessels. The flow of the portal blood into the heart when the two are connected by a canula, serves to establish two important facts : 1. That the portal circulation is obstructed in the liver when respiration is suspended, the blood in consequence rapidly accumulating in this system of vessels. 2. That the action in the heart is inadequate for the portal circulation, which requires a greater force than this for effecting it In short, the body being based upon pressure and the power of producing rapid rhythmical changes in pressure, nothing short of the pumping action in the abdomen, which is set up by respiration, and the rhythmical changes in pressure w hich this produces in the viscera, would be sufficient for the purpose. And when we get a little further on in the mechanics, it will •be shown how this action in the abdomen for increasing the portal circulation is mnde to connect with the action in the in- DEPENDENCE OF POETAL AND SYSTEMIC CIECULATICN. 71 testines for increasing the digestive and absorptive processes for producing correspondence and maintaining a balance in this circulation, inclusive of the action in the lymph- channels, which cannot be omitted in the scheme. The rapid absorption of fat, albumen, alcohol, which are non-dialyzable, hence will not pass the membranes without mechanical force, are alike included in it. In fine, the explanation of the portal circulation, to be satisfactory, should embrace the entire me- chanics for increasing circulation in the abdomen, and for maintaining this in correspondence with the physiological requirements in the organism ; and which, of course, should include the extensive nervous connections subsisting in the viscera, together with the arrangements of the structures in the organs as means to ends All of which have ample explana- tion. It comes to this, then, that the heart is not able to carry on the portal circulation, as is fully proven by the above experiment. But that is not all that is proven by this experiment. ISay ! not by half and more. Put this great fact in the foreground of the mental picture : When the respiratory centre is destroyed, both the systemic andportal circulations arepromptly arrested; this notwithstanding the heart is beating with perfect regular- ity and unaltered frequency ! The mechanical work this organ is capable of is far too inadequate for the enormous labor which is involved in the circulation, the non-arrival of the blood at the heart, the empty condition of the chambers, the "collapsed" vense cavee, together with the swollen and turgid portal system, are all eloquent of that fact ; showing conclu- sively that the cardinal circumstance in the circulation is the great pumping movements which oire set up by respiration, extending from the lungs to the tissue-territories and from surface to surface of the body ; for to the movements takings place in the chest and abdomen there are rhythmical expansions and contractions of the arterial and capillary systems, inclusive of the venous, synchronous with respiration for producing cor- respondence and maintaining a balance in the circulation ; otherwise impossible. But with progress in development ' ' ribs' ' are differentiated in the external walls, or muscular envelope, with a system of 72 RESPIRATION IN BIRDS. "internal" and "external intercostal muscles' ' for operating tli em in connection with the action in the lungs, the other muscles in the envelope also powerfully assisting, whereby the action in the lungs is greatly increased. This arrangement sub- serves a double purpose : it protects the lungs against the rude experiences to which the animal is exposed, so as to prevent " collapse'" of the organs ; at the same time it enables the ex- pansions and contractions to be more readily effected. In short, it energizes the action in the lungs. But as the action in the "ribs" is exhaustively treated in existing works, it will not be necessary to consider it here further than to refer to the action the diaphragm exerts upon them, which will be taken up after briefly referring to respiration in birds, the matter having escaped attention. Respiration in Birds. — Passing, for the sake of brevity, over the intervening stages in development, as the action is fundamentally the same throughout, and for the reason, also, that it is so conspicuous in them, moreover so abundant and accessible, we take up respiration in the birds ; and being, also, warm-blooded, this brings us nearer to the higher animals, where interest culminates. The structures in birds are homolo- gous with the reptilian and mammalian, upon either side of them, the special modifications that obtain in them being adaptive changes to the stage in development simply. But as yet no diaphragm appears for separating the viscera in the abdomen from the viscera in the chest, which comes into the scheme in the succeeding stage in development as a special adjustment to the altered mechanics in the intestinal canal for increasing the digestive and absorptive processes, the portal and lymph circulations which will be taken up after the systemic circulation shall have been disposed of as they can be treated more advantageously by following this method ; besides, that method should be adopted in the treatment which would connect all the phenomena, anatomical and physiological, in one harmonious whole, and make everything plain and easily understood. The point we wish to empha- size in this connection, however, is, that, notwithstanding the absence of a diaphragm, the birds respire easily and readily, can produce high vocal resonance, carry whole notes, and make RESPIRATION IN THE ABSENCE OF A DIAPHRAGM. 73 all the varied sounds peculiar to them, showing that respiration is not only under voluntary control, and all the parts fully coordinated, but at the same time is very energetic. And as development is by addition and differ- entiation, in order to understand respiration in mamma- lia, respiration in birds and reptiles would first have to be understood. The question, then, resolves itself into this : What is the mechanics for producing the rhythmical changes in pressure within the lungs of birds for compelling afflux and efflux of air and blood in the organs for respiratory purposes ? — when it will be in order to inquire as to the role in the dia- phragm for still further increasing the action. Briefly, respira- tion in birds is accomplished by means of rhythmical expan- sions and contractions in the abdomen and chest, producing a to-and-fro movement of the viscera in the longitudinal axis of the body ; the viscera in the abdomen being in contact with the lungs, fitting accurately against them and moving in and out of the excavation, piston-like, under the action of the muscles in the abdomen ; while the lungs are in concert with this movement, expanding and contracting simultaneously and synchronously, whereby low and high pressures are alternately produced within the lungs themselves, which the scheme calls for for producing afflux and efflux of air and blood in the alveoli, at the same time confining the fluids within their channels ; otherwise impossible. This, then, is the explanation of the pumping action in the abdomen of the birds ; the expansile action corresponding with inspiration, the contractile with ex- piration. And when at rest upon the ground, the hinder parts are raised and lowered alternately by this action in the abdo- men, and is so conspicuous that the respirations may be readily counted at a distance from the body ; rising during inspira- tion and falling again during expiration. Brief reference to the anatomy is necessary. Descriptive Anatomy. — In the first place, the costal frame- work forms an ovoidal cavity ; the small contracted end pre- senting anteriorly at the root of the neck, while the large expanded end, presenting posteriorly, is open and in free com- munication with the abdomen, some of the viscera lying with- in it (Fig. 22). The skeleton itself, however (Fig. 23), gives 74 RESPIRATION IN THE ABSENCE OF A DIAPHRAGM. no idea of the extensive abdominal cavity which forms the large end of the common ovoidal chamber. But by contrast- ing the cuts a mental picture may be formed. For example, the long, narrow innominata (Fig. 23, s, s' , s"), one for each side, together with the narrow os sacrum, form the roof of the cavity ; while the £>osterior (p) and lateral walls are formed of soft parts, principally muscles, which are homologous with those in the higher animals. But in order to fully expose the Fig. 22. — Longitudinal sect'on of the Thoracic- Abdominal Cavity iu the Hen, showing the viscera in situ. The outline of the ovoidal cavity is unpaired by allowing the acetabulum (k) to remain. A, ventriculus callosus ; B, liver ; c, intestines ; d, kid- ney ; c, lungs ; F, heart ; h, left pulmonary artery ; g, left anonymous artery ; i, ovisacs ; k, acetabulum ; /, glenoid cavity ; m, ribs ; n, process of sternum ; o, pectoral muscles ; p, abdominal walls ; r, nasal orifices ; S, proventriculus ; s, oesophagus ; L, atmosphere. whole of the abdominal portion of the chamber, however, the whole forming a perfect ovoid, the innominatum also would have to be removed, thus bringing into view the whole of the intes- tines, a few coils only now presenting (Fig. 22, c), the rest being contained in the pelvic excavation. The anterior ex- tremity of the bone corresponds with d, the posterior with the RESPIRATION IN THE ABSENCE OF A DIAPHRAGM. 75 Fig. 23.— Skeleton of a Fowl.— Chauveau. Frcm A to B, cervical vertebras— 1, spinous process of the third vertebra ; 2, inferior ridge on body of the same ; 3, styloid pro- longation of the transverse process of the same ; 4, vertebral foramen of the same : 1', 2', 3', 4', the same parts in the twelfth vertebra. From B to C, dorsal vertebrae : 6, spinous process of the first ; 7, crest formed by the union of the other spinous pro- cesses. From D to E, coccygeal vertebrae ; F, G, head ; 8, interorbital septum ; 9, foramen of communication between the two orbits ; 10, prem axillary bone ; 10', external openings of the nose ; 11, maxilla ; 12, square bone ; 13, jugal bone ; H, sternum ; 14, brisket, or keel ; 15, episternal process ; 16, internal lateral process ; 17, lateral external process ; 18, membrane which closes the internal notch ; 19, membrane of the external notch ; J, etc., superior ribs ; 20, posterior process of the fifth ; J, inferior ribs ; K, scapula ; L, coracoid bone : M, furculum ; m, m, its two branches ; N, humerus ; O, ulna ; o, radius ; P, P7, bones of carpus ; Q, Q', bones of metacarpus ; B, first phalanx of the large digit of the wing ; r, second phalanx of the same ; B', phalanx of thumb ; S, ilium ; S', ischium ; £", pubis ; 21, sciatic foramen ; 22, foramen ovale ; T, femur ; U, patella ; V, tibia, X, fibula ; F, single bone of tarsus ; Y, metatarsus ; 23, superior process, representing a united metatarsal bone ; 24, process supporting the claw ; Z,etc, digits. 76 ADJUSTMENTS IN THE VISCERA. commencement of the soft abdominal walls, midway between p and A\ By contrasting the corresponding parts in the skeleton (Fig. 23) some idea may be formed of the length and depth of the pelvic excavation, and the great extent of the muscular structures forming the sides and floor of the abdomen. Now, then, in regard to the mechanics in respiration. As will be seen, the solid and heavy viscera, notably the ventriculus callo- sus and liver, are at the very bottom of the cavity, the liver resting against the projecting sternal processes (Figs. 22, A, B; 23, H, 16), with all the other viscera resting upon them as their floor of support, the ventriculus itself resting entirely upon the soft abdominal walls (Fig. 22, A,p). The sternum, by projecting long, slender processes toward the abdomen, aids considerably in supporting the liver, but the weight in the greater portion of the viscera is sustained by the abdominal muscles simply, and these, by being inserted in the sternal pro- cesses, aid in supporting the liver also, together with the overly- ing viscera, so that all are necessarily affected by the action in the walls. Finally, the stomach (ventriculus) and liver are firmly secured to the posterior walls by means of duplicatures of the lining membrane (Fig. 22, A, B, p), the lobes of the liver extending far down the sides of the ventriculus in form of a saddle, and secured by means of connective tissue and the overlying peritoneum, so that the two are compelled to move together under the action in the walls. It results from this arrangement in the parts, that with every expansion in the abdomen the viscera are pulled downward and backward, gravi- tation and the traction from the retaining ligaments compel- ling this circumstance : while during contraction they are pushed in the opposite direction, or forward and upward. In the former, they tend to pull away from the lungs, thereby tending to produce low pressure in the visceral cavity itself ; but as this would defeat the end in view, the lungs expand simultaneously and par I passu with expansion in the abdomen for maintaining the intra-abdominal pressure, keeping in close apposition with the viscera for this purpose ; which has the effect of confining the low-pressure area within the lungs themselves for aspirating the air and blood for respiratory MODE OF PKODUCLTSTG AFFLUX AND EFFLUX IN THE LUNGS. 77 purposes, otherwise impossible, since the fluids flow from high to low pressure, in conformity with universal law. During contraction, however, when the action is reversed, the viscera are firmly compressed against the lungs, which maintains intra-abdominal pressure, at the same time that high intra- pulmonic pressure which this produces causes the fluids to flow out of the organs again till pressure is uniform, the lungs also contracting pari passu with contraction in the abdominal muscles for increasing the action. Finally, for effecting co- ordination we have the pneumogastric and spinal nerves, or the same as in the frog, the principle being the same. So, then, at no time is there any difficulty in producing the requisite changes in pressure in the alveoli for compelling afflux and efflux of air and blood in the chambers for respiratory pur- poses, at once the object and purpose of all these arrangements. But did not the lungs expand during inspiration in the manner alleged, the effect would be to develop low pressure wit kin the abdomen itself, which would defeat the end in view by causing afflux of the fluids in this locality, in consequence rapidly putting an end to life. Not outside of, then, but within the lungs themselves must low pressure be made dur- ing inspiration, in order to keep the fluids in their relative channels, as before remarked. This, then, is the explanation for the pumping action so con- spicuous in the abdomen of the birds ; and having no dia- phragm for pulling the viscera away from the lungs during inspiration, they are fastened by means of duplicatures of the lining membrane to the posterior abdominal walls, thereby obviating the necessity for a diaphragm. And with the big end of the excavation, containing the greater portion of the viscera, the heavier at the bottom, the whole inclined at an angle of about 30 degrees (Fig. 22),* gravitation would neces- sarily favor inspiration, enabling expansion to be more readily made by adding its force to the force in the muscles, thereby im- parting energy to the movement. The result of this action is to compel the air (L) to flow into the air-passages and alveoli through the nasal orifices (r) till pressure is uniform, the ve- * In the skeleton, the student must look from the abdomen upward, filling out the soft tissues in his mind, in order to get the angle of inclination. 78 MODE OF PRODUCING AFFLUX AND EFFLUX IN THE LUNGS. nous blood at the same time flowing into the alveolar plexuses from every portion of the body, the heart serving to assist the action, as has already been stated :* while for compelling them out again, we have simply to reverse the action in the abdomen and lungs in the manner as stated — the one flowing out by reflux action through the route of ingress, the other into the left chambers of the heart and arterial system on its way to the cell-brood, the heart, of course, assisting the ac- tion ; otherwise it were impossible to produce the high press- ure in the arterial system for increasing the capillary circula- tion commensurate with the physiological requirements, in order to generate the force which is expended, the main- tenance of the upright position itself alone demanding rapid circulation for effecting it, and which, of course, would involve rapid respiration, as in no other way could a balance be maintained. Hence the rapid pumping action in the »abdomen of the birds. But while this action is going on in the abdomen and lungs, however, the chest itself expands and contracts simultaneously for increasing the action, thereby enabling the lungs to expand outward as well as downward, which the action in the lungs calls for. But it is not so extensive as the action in the abdomen, save in the portions contiguous to the abdomen, into which the muscles of the latter have insertion, notably the long, slender sternal processes (Fig. 23, J3, 16, 17) and adjacent ribs, and which, of course, are com- pelled to respond to the action in the muscles, thus making the movement in respiration conspicuous in them ; the length of the muscles in the abdomen being the explanation of this circumstance, since the amount of elongation and shortening in the muscles is determined by their length ; hence, the rhythmical expansions and contractions in the abdomen dur- ing respiration are necessarily much greater than in the chest. Morever, the ribs in birds do not partially revolve around the long axis for flaring them open upon the sides, as in other animals, the long costal processes (20) effectually preventing it, this, together with the forked articulations to the spine, for * The author indulges the hope that the importance and gravity of the sub- ject will serve as apology for frequent reiteration of the cardinal points in order to enforce attention and stamp them indeliby upon the mind. MODE OF INCREASING IT IN FLYING. 79 imparting firmness to this portion of the framework, as the base of support to the wings. At the same time, however, we have to note a compensatory arrangement for maintaining expansile and contractile action in the chest ; and this consists in a series of cartilaginous articulations in the mid-costal region, dividing the ribs into two portions, or "superior" and "inferior" ribs (Fig. 23, I, J), which join each other at an obtuse angle, form- ing an elbow ; while below they connect with the sternum by terminal cartilages, in the usual way; so that the chest can readily be expanded or contracted by the overlying muscles, being forcibly compressed by means of the contracted abdomi- nal muscles during expiration, and springing forcibly out again with expansion in the muscles during inspiration ; the pectoral muscles also assisting in the action, especially during flight. And as this arrangement in the ribs Occurs only in birds, it is highly probable this is the case ; so as to compel respiration to be in correspondence with the increase in the activities. Thus, the powerful pectoral muscles covering the whole anterior and lateral portions of the chest, have their broad points of origin in the keel (Fig. 23, 14) (the widely- expanded process projected from the central portions of the sternum for this purpose), while the points of insertion are in the head and proximal portions of the shaft of the humerus ; hence, every effort to extend and retract the wings would tend to expand and contract the chest correspondingly, the points of origin and insertion being movable ; consequently, would have to be separated or approximated by the expansions and contractions in the muscles, as this would increase or diminish their length correspondingly. In this manner, then, respiration is increased with the flight, which is the physiological finality in this adjustment ; at the same time, however, it enables the energetic action in the lungs, for producing loud vocal reso- nance, to be more readily made. In this condition the pos- terior portions of the chest are forcibly compressed by the energetic contraction of the abdominal muscles, thereby dimin- ishing the transverse with the longitudinal axis in the visceral cavity, and which, of course, must effect corresponding com- pression of the lungs for producing the high intra-pulmonic pressure which is essential for producing the vibrations in the 80 CIRCULATION IN THE AIR-SACS AND BONES. vocal cords ; the one involving the other. And in order to obtain some idea of the enormous role performed by the viscera and the muscles in the abdomen in respiration, one has need only to watch the action of these parts in the screaming parrot, and he will perceive that the viscera are more and more com- pressed into the chest-excavation by the action in the mus- cles as the notes are prolonged or raised in volume, the abdomen in consequence becoming more and more flat and reduced in size, till at the end of the note the greater portion of the viscera are in the chest excavation ; at the same time, the lower chest- walls are firmly held down by the muscles in the abdomen, that the force may be concentrated in the lungs. At the end of the effort they fly back to the original positions under the ener- getic expansion in the muscles, aided by the resiliency in the ribs, in which force is stored during contraction, to be yielded up again during the subsequent expansion, so that nothing is lost, but only carried over from one rhythmic movement to the other In quiet respiration, however, the motion in the trunk seems limited to the abdomen and the proximal portions of the chest. In addition to this mode of respiration in the lungs, the birds are provided with air-sacs, the whole thoracic- abdominal cavity being divided by septa of serous membrane into numerous inter-communicating chambers, all of which are freely supplied with air, brought into them through the bronchial tubes, which open upon the lung surface, passing through and through the lung substance for this purpose (Fig. 24, a, e), the air being admitted to the very bones them- selves ; and in birds of powerful flight penetrating even be- tween the muscles of the neck and limbs. And it is easy to per- ceive how the action in the abdomen and chest should increase this circulation also by expanding and contracting the air- sacs correspondingly, at the same time compelling the air into and out of the bones with afflux and efflux of air in the lungs, and enabling them to readily inflate the sacs for buoying them in the media when swimming or flying, by diminishing the body-density, and increasing surface correspondingly. It is needless to extend the matter. In conclusion : It is manifest, from this relation of the parts PORTAL CIECULATIOlSr. 81 in the abdomen, that the pumping action in respiration should increase the portal circulation correspondingly. Thus, the liver substance being spread out, as it were, against the firm Pig. 34.— Lungs, Heart, and Great Vessels of Buteo Vulgaris.— Gegenbaur. tr, trachea ; i, crop ; ae, communication between the air-sacs and the lungs ; 6, bursa f abricii ; ao, aortic arch : aad, art. anonyma destra ; aas, art. anonyma sinistra ; ps, art. pulmonalis sinistra ; c, carotid ; am, visceral artery ; vci, commencement of the inferior vena cava : vcm, vena coccygeo-mesenterica. 82 PORTAL CIRCULATION. ventriculus (Fig 22, B, A), with the other viscera resting upon them, must necessarily undergo a degree of compression with every expiration, and increasing till the end of this, which would tend to force the blood through the open hepatic veins, the aspiratory force in the heart, which is close to the organ, being added to this ; while during inspiration the organ, by spring- ing back again to the original shape, should produce a suction- force upon the portal blood, at the same time the suction force in the lungs is added to that in the heart for aspirating the blood in the liver; so that inspiration must necessarily increase circulation in the liver. It must do so, in the very nature of things. Of course, the same applies for the viscera in the abdomen, connected with the lower eava system CHAPTER V. RESPIRATION IN MAMMALIA. Respiration in the Mammalia Fundamentally the Same as in Birds and Reptiles, the Lungs and the Muscles in the Abdomen Expanding and Contracting Simultaneously — Office of the Diaphragm and the Occasion for it— The Action in the Diaphragm Alternating with the Muscles in the Abdomen, the One Contracting as the Other is Expanding, and Vice Versa — The Action the Diaphragm Exerts Upon the Ribs, Bending and Flaring Them Open Upon the Sides During Inspiration, and Vice Versa During Expiration — Mode of Coordination, Inclusive of the Lungs, the Whole Moving in Perfect Con- cert— Circumstances in the Vital Phenomena, Anatomical and Physiological, which Make it Absolutely Certain that the Lungs Expand and Contract Regularly and Rhythmically Synchronous with the Actions in the Diaphragm and Containing Walls — Physiological Experiments Proving This Circumstance — The Action in the Tracheal System — Mode of Maintaining Cleanliness in the Alveoli and Air-Pass- ages— Significance of a Cough — The Action of the Trachea in Vocalization — Expla- nation for the Devious Course of the Recurrent Laryngeal Nerves, which First Descend Into the Chest to Connect with the Lungs Before Proceeding to the Larynx and Vocal Cords, Ascending Thence Upon the Trachea for This Purpose, No Matter How Long the Neck May Be ; e. g. , the Giraffe. This brings ns to Respiration in the Mammalia. From what has preceded, it follows that the first thing to engage the attention of the student of physiology is the relation which the viscera sustain to the muscular envelope or containing walls, since it is by means of the rhythmical expansions and contractions taking place in the latter that the relative changes in pressure are produced in the former for compelling afflux and efflux of air and blood in the aveoli for respiratory purposes ; the viscera, of course, being responsive to the movements in the walls in order to effect these results, and in close contact with them all the while. In short, that the principal force for producing the requisite changes in pressure for effecting respi- ration in mammals inheres in the muscular envelope itself, with which the internal parts are coordinated by means of the nervous apparatus, as obtains in the preceding stages in development, the principle being the same ; only there is increasing differentiation in the organs, with the development 84 FLOOR OF SUPPORT TO THE VISCERA. of a special organ or structure (diaphragm) for separating the viscera in the abdomen from the viscera in the chest, and which is rendered necessary by the changes which have occurred in the intestines for increasing the digestive and absorptive processes commensurate with the force which is expended in these animals, which are womb-bearers, and oc- cupy a higher plane in development. In present physiology the weight in the viscera receives little attention, which is a great oversight, as the whole of them, with the entire body itself, have adjustment with gravitation, so that it would be utterly impossible to explain the phenomena in the absence of this essential factor. iN ow that attention is called to it, the necessity for this strong floor of support to the viscera in the abdomen will at once appear obvious, since the folds of lining membrane forming the ligaments for retaining them in their relative positions, at the same time permitting free movement in them in connection with the special functions, contain the nerves and blood vessels to the viscera, which would at once inhibit much traction upon them ; otherwise inevitable but for this floor of support. The weight, too, is very consid- erable, approximating one-fifth of the weight in the body. So, then, we can readily understand why the heavy viscera should occupy the bottom of the cavity, while the floor of sup- port should be substantial, the liver itself resting against the sternum, with the stomach and intestines against the muscular walls. But in order to fully appreciate the mechanics, it will be necessary to again refer to the special anatomy in the parts. Descriptive Anatomy.— As will be seen, the muscular en- velope still functions as the floor of support to the viscera (Fig. 25, i£), though the relative positions they sustain to each other are somewhat changed. Thus, while the liver (L) is still in front of the stomach (S), and resting against the sternum and ribs, as in the birds (Fig. 22, B), it is not intimately attached to the stomach, but is attached to the incurvated surface of the diaphragm instead by duplicatures of the lining membrane; while the stomach itself, now widely expanded, is in easy con- tact with it simply, and free to move in the visceral cavity, that it may function both as a receptacle for the food and at the same time effect digestive action in it ; and that the intestines, FLOOR OF SUPPORT TO THE VISCERA. 85 also greatly increased in size, are not now resting upon the liver and stomach as the floor of support (Fig. 22, c, c, B, A), but occupy a position posteriorly and resting against the mus- cular floor itself, in easy contact with them (Fig. 25, i", C — E, S, L) ; at the same time, are also free to move within the cavity in connection with respiration and the special functions in the organs ; while they are retained in their relative positions by means of duplicatures of the lining membrane, forming the gastric, meso-colic and mesenteric ligaments. From this rela- tion of the parts, it follows that the viscera are compelled to Fig. 25. — Diagrammatic Longitudinal Section of the Abdomen in the Horse, showing the position of the Viscera, and the relations they sustain to the lower abdominal walls, or floor of support. E, abdominal walls ; S, stomach ; L, liver ; O, omentum ; C, colon ; M, mesentery ; I, small intestines ; Q, duodenum ; P, pancreas ; B, bladder ; V, vagina ; B, rectum ; d, diaphragm ; k, oesophagus ; A, aorta. respond to every movement in the muscular walls. It could not be otherwise, in the very nature of things. Thus, during inspiration, when the muscles expand, the viscera sink down, so to speak, with the walls ; but when contraction sets in dur- ing expiration, they rise again with them, in this manner effect- ing a to-and-fro movement of the viscera in the chest-excavation during respiration for producing the rhythmical changes of pressure in the lungs ; while the large apron-like duplicatures of the lining membrane forming the great omentum (o) inter- vening between them and the floor, facilitates the gliding move- ments and obviates friction, the secretions in the lining membrane serving also to lubricate the organs, thus reducing friction to a minimum, the mechanics being fundamentally the same as in 86 OFFICE OF THE DIAPHRAGM. the birds and reptiles. Now, then, in regard to the diaphragm. In addition to the great increase in size of the stomach and intestines, they are now filled and distended with air (Fig. 25, 8, C, 31), which tends to balloon them in the cavity, and but for this diaphragm for restraining and operating them in con- nection with respiration, would rise up in the chest-excavation and inhibit the action in the lungs, putting an end to life. Hence this circumstance. At the same time, however, this calls for the phrenic nerves (Fig. 91, F), which are correlated with the other nerves in the medulla oblongata for operating the organ in connection with the muscular envelope and lungs, all the parts acting in har- monious concert as previously, in order to produce the changes of pressure in the alveoli. In fine, the old founda- tions are simply built upon and further extended for produc- ing a larger amount of work commensurate with the force expended in the organism, while . the principle in the me- chanics remains unchanged and unchangeable, from the very nature of things. Thus, with inspiration the diaphragm con- tracts for pulling the viscera away from the lung-region, while the abdomen expands simultaneously and pari passu with this action, in order to make requisite room for descent of the diaphragm and lungs, which expand synchronously with the muscles in the abdomen, as before ; while during expiration the action is reversed simply, the diaphragm expanding simultaneously and pari passu with contraction in the abdominal muscles and the lungs, in order to effect this action. In short, the old mechanics continues in operation as it ever did, while the dia23hragm comes into the scheme as an adapta- tion to the changes effected in the stomach and intestines, for increasing the digestive and absorptive processes, and without which they never could have been made, leaving development at the stage in the birds. And let it not be ima- gined that the powerful muscles in the abdomen are made to yield to the force in the diaphragm, and are pulled into exten- sion by this means, which cannot be thought of for a single moment even, the vast preponderance of the muscles, of itself alone, inhibiting this action ; if, forsooth, such rude mechanics were at all admissible. OFFICE OF THE DIAPHRAGM. 87 The large undulation, extending over the abdomen during inspiration, is produced by expansion in the muscles, together with contraction in the diaphragm for pushing the viscera along pari passu with this action for occupying the space thus made, in this manner creating the billow ; while during ex- piration the action is reversed, the contraction which then sets in in the muscles of the abdomen causing the wave of reflux in the viscera, which return again into the chest, the dia- phragm at the same time expanding pari passu with contrac- tion in the walls, till at the end of a forced expiration most of the viscera are in the chest-excavation, leaving the abdomen less than one-half the size it had at the end of inspiration. Indeed, in an athlete this recession of the viscera in the chest may be made so complete by the energetic action of the muscles as to remove nearly all the lower coils of the mesentery, so as to bring the walls in actual contact with the lumbar vertebrae (Fig. 128), which are easily felt. Of course, the diaphragm, with the lower chest-region, ex- pands correspondingly in order to effect this action ; otherwise impossible.* So, then, it is very readily perceived that the diaphragm is in perfect concert with the muscles in the abdo- men ; only that the action is reversed in them, the former con- tracting as the latter are expanding, and vice versa. The extensive aciion which this involves to the viscera is amply provided for by the long ligament in the mesentery (Fig. 25, m), which permits the loose coils of intestine to readily glide over each other for the purpose ; at the same time, they are freely lubricated by the secretions in the membrane. But as we shall have occasion to refer to this again, in con- nection with the functions in the abdomen, it need not detain us here, and we pass on to the special phenomena in respira- tion, taking them up as we go along. The Action the Diaphragm Exerts upon the "Hibs." — The relations which the diaphragm sustains to the ribs, and the manner they are affected by its action, are in keeping with the comprehensiveness in animal mechanics and the * But as life advances the cartilages become more and more ossified, while fat accumulates in the viscera ; hence, this extreme action becomes more and more difficult. 88 DIAPHRAGM OPERATING THE RIBS. wonderful utilitarian methods which everywhere obtain, Thus, while contraction in the diaphragm increases the longi- tudinal axis in the chest, it at the same time compels the ribs to flare open upon tlie sides for increasing the trans- verse axis simultaneously, so that the lungs may expand outward as well as downward for increasing the action in them correspondingly. And while it is true that the ribs expand in the absence of a diaphragm for effecting it, as is fully proven in birds and reptiles, nevertheless the converse is equally true, as I have fully demonstrated upon the dog and cat by denuding the chest of its muscles * (the animal under chloroform) without embarrassing respiration in the least, while the ribs continued to expand and contract in the usual way. In point of fact, the intercostal muscles share in the general muscular paresis which accompanies chloroform nar- cosis, f Moreover, " sex" would seem to exert no influence in this respect, the action in the chest and abdomen being as con- spicuous in the female as in the male, there seeming to be no difference in them. And by thus eliminating the intercostal muscles, chloroform furnishes a crucial test of this action in the diaphragm and ribs. The explanation of the mechanics is sufficiently easy, notably : The diaphragm is attached to the ends of the ribs, being inserted in the cartilages (Fig. 26, 9), whence it is ballooned in the chest by the viscera (Fig. 27) so as to bring the muscular fibres in correspondence with the long axis in the ribs (A,f,f) ; hence, when contraction sets in during inspiration, the traction would necessarily be upon the ends of the costal bows, tending to bend and flare them open upon the sides like the ribs in an umbrella, while their resiliency would impart elastic action to expiration with relief in the traction force which this produces. The natural curva- ture of the ribs, being also slightly twisted upon the long axis, * In destroying the intercostal muscles, great care is necessary to prevent puncturing the pleurae, which is extremely difficult. •{•This circumstance I had seen strikingly illustrated after the removal of a malignant tumor of the chest, in which the intercostals were laid bare, and which flopped to and fro during respiration, being pushed in and out alter- nately by the changes in pressure within the chest, which continued to expand and contract in the usual way. DIAPHRAGM OPERATING THE RIBS. 89 Pig. 26. — Showing the manner in which the diaphragm is attached to the cartilages of the inferior ribs, viewed from below. — Cbauveau. 1,1', pillars of the diaphragm ; 2, left pillar ; 3, common tendon ; 4, tendinous attachments to the cartilages ; 4', muscular attachments ; 5, attachments to control tendons ; 6, vena cava opening ; 7, oesophagus ; 8, aorta ; 10, psoas magnus ; 11, psoas parvus ; 12, transverse pro- cess of lumbar vertebra ; 13, superior or external lumbar muscles. Diaphragm of the Horse ; Posterior Face. — 1, 1', the two portions of the right pillar ; 2, left pillar ; 3, tendons of the pillars ; 4, 4', peripheral muscular portion ; 5, left leaflet of the aponeurotic portion ; 5, 5', right leaflet of the same ; 6, posterior vena cava ; 7, oesophagus passing through the opening in the right pillar ; 8, posterior aorta between the two pillars ; 9, cartilaginous circle of the ribs ; 10, 11, section of the psoas muscle ; 12, section of a lumbar vertebra ; 13, section of the common mass ; 14, retractor muscle of the last rib ; 15, xiphoid appendage of the sternum. 90 RESPIRATORY ROCKING IN THE BODY. must inevitably cause them to revolve in the long axis in in- spiration, and thus flare them open upon the sides. At the same time, the external intercostal muscles should in- crease the action in inspiration, while the internal, by acting in the opposite direction during expiration, should impart corre- sponding energy to the reverse action, so that the force in these muscles is still utilized in respiration, though not essential to it. But there is concert of action throughout, so that all act together ; and which is readily accomplished by the cor- relation of the nerves in the respiratory centre, the intercostal nerves supplying the external parts, inclusive of the muscles in the abdomen ; the phrenic and pneumogastric nerves the in- ternal parts, whereby correspondence is produced during inspiration and expiration as in the previous stages in devel- opment. This action in the diaphragm and ribs would also explain another curious circumstance, notably the to-and-fro movement in the head and shoulders during respiration, or backward and forward, otherwise inexplicable. 1 n other words, the head and shoulders are rocked to and fro by the action in the diaphragm and ribs during respiration, and the deeper the inspirations the more conspicuous it becomes. As we have said, the diaphragm is inserted into the ends of the ribs, and with the viscera against its breast in the chest-excavation with the spinal column as the point of resistance, it is mani- fest that, with contraction in the diaphragm, this would tend to push the spine backward during inspiration ; but when relief comes during expiration, which reverses the action, the spine would return to its original position. Hence the oscillations in the head and shoulders during respiration. In the quad- ruped, this circumstance is seen in the sudden shooting for- ward of the whole body, produced by the occasional deep and energetic inspirations which the animals take, especially after rousing from slumber and during digestion ; the whole body rocking forward upon the limbs under the energetic action in the diaphragm, exerted through the ribs and spinal column. It is deeply interesting. One other circumstance of deep im- port remains for mention in this connection, though we shall not do more than make a passing reference, as the matter pertains more particularly to another work.* Notably, by * See "Gravitation and Development." EESPIKATORY EOCKING IN THE BODT. 91 the action in the diaphragm the viscera are thrown against the anterior walls of the abdomen during inspiration, moving downward and backward in place of directly backward ; the object being to avoid impact in the pelvic viscera, which would tend to force out the contents and produce strain in the organs, hence must be avoided. And by attaching the diaphragm to the lumbar vertebrae and the ribs in the manner as obtains, Fig. 27. — Section of the chest-walls, showing position of the diaphragm in the excava- tion and the relations it sustains to the lungs and ribs, the muscular fibres corre- sponding with the long axis in the ribs (A, F, F). A, diaphragm ; B, lungs ; C, heart ; D, pericardium, reflected ; E, sternum ; F, ends of the ribs. with the muscles acting in the long axis in the ribs, this action in the viscera is readily effected, so that impact in the pelvic viscera is entirely obviated, which, for reasons already given, must apply for every stage in development The de- pression which occurs in the epigastric region during inspira- 92 ACTION IN THE LUNGS. tion is due to the bending in of the costal and ensif orm cartilages produced by the traction in the diaphragm ; but as life ad- vances and they become more and more ossified, it is less and less conspicuous by reason of the rigidity this produces in the structures. Thus, these adjustments in the diaphragm are far- reaching. Concerning the Action in the Lungs.— During inspiration the lungs expand as the diaphragm contracts, and simulta- neously, expanding with a force sufficient to firmly approxi- mate them to the diaphragm and costal surfaces, for obviating low pressure in these localities and producing this in the alveoli only, expanding outward and downward, following the diaphragm and completely filling the pleural cavities ; while during expiration the action is reversed, the organs now con- tracting and moving upward and inward, the ribs against the sides, and the diaphragm with the viscera in the abdomen push- ing against the bases for producing high pressure in the alveoli, while the air and blood flow into and out of these compart- ments simultaneously in order to equalize pressure, fluid equi- librium compelling them to do so, since both are in direct communication with these localities, each by means of a special system of canals in correspondence with the special' require- ments, the veins and capillaries being also very soft and com- pressible. The reasons why this should be as stated are simply un- answerable, notably : 1 . Did not the lungs expand pari passu with contraction in the diaphragm, the result would be to develop low pressure in the pleural cavities, caused by the pulling away of the dia- phragm and ribs from the lungs, which would virtually con- vert them into a huge cupping apparatus for sucking the fluids into the pleural cavities, and thereby destroying life by producing fatal compression of the lungs, since pressure is transmitted through and through the body ; and the fluids would inevitably flow into the low-pressure areas to equalize pressure. It could not be otherwise, in the very nature of things. Furthermore, were the lungs passive, or as bags simply, resistance would increase with the traction force upon them ; ACTION IN THE LUNGS. 93 hence, during inspiration, there should be progr ess ive increase of suction-force in the pleurae, caused by the lungs pulling one way and the diaphragm with the chest-walls the other ; hence, the deeper the inspiration, the more effective it should be for aspirating the fluids into the cavities of 'the pleurae. Tn other words, a force which acts in all directions and upon every fluid without distinction cannot be made subservient to the convenience of a theory which would limit its action to a single fluid (atmosphere), and confine this within specific limits or to the lungs simply, and ignoring the blood altogether. Even in this case, however, it would be ineffectual, since the air immediately adjacent to the pleurae in the air-vesicles should be first affected before the outside air could be aspirated^ drawing it into the pleurae. The action has been compared to the one taking place in a "bellows;" but the simile fails at an essential point, for there never was a bellows with a pair of lungs inside of it in which a dual circulation of air and blood is carried on. And though the law of pressure which applies is the same in both, it had not been followed to its logical results, else this unfortunate and hasty comparison,, tending to retard physiological inquiry, would never have been made. So, then, we conclude that this bellows-principle cannot pos- sibly be the mode of respiration, but that the lungs perform an active role, and by expanding synchronously with expansion in the chest following the descent of the diaphragm and elevation of the ribs, the conditions obtain during inspiration for produc- ing simultaneous afflux of air and blood in the alveoli for respi- ratory purposes, at once the object and purpose of the mecha- nism ; since this would have the effect of producing high pres- sure in the pleurae, with low pressure in the alveoli, making this the culminating point of the changes in pressure, which • the scheme calls for. While during expiration, which answers to systole in the lungs, the high pressure which this produces in the alveoli causes the air and blood to flow out of these com- partments simultaneously, the former by reflux action through the route of ingress, the latter into the left cardiac chambers and arterial system on its way to the cell-brood in the tissues, 94 ACTION IN THE LUNGS. the objective point of the commerce, as before remarked ; and the whole surface of the organs being closely embraced by the containing walls closing tightly around them, the ribs upon the sides, with the diaphragm and viscera pressing against their bases from below, must necessarily produce high pressure in the pleurae, whereby the walls of the alveoli are well sup- ported for obviating rupture during expiration. Hence, at no time is there low pressure in the pleurae, the principle under- lying the mechanics inhibiting it, as we very well know. In this manner, then, a balance is maintained for keeping the fluids in their channels, as the body is expanding and contract- ing regularly and rhythmically, like the diastoles and systoles in the heart, for pumping air and blood through the alveoli simultaneously for respiratory purposes, while the demands of imperious law are fully satisfied. So much for the principle underlying the mechanics in res- piration, which is plain enough 2. Under this head are included a number of reasons apper- taining to the special vital phenomena, anatomical and physio- logical, otherwise inexplicable, to which brief reference will be made. Indeed, no theory of respiration can possibly hold its ground which does not include, nor can include, the special phenomena in the structures and functions in the lungs, and which, of course, would include the nervous arrangements for co- ordinating the muscular envelope and blood-vascular system with them, in order to produce the rhythmical changes of pressure in the organs for compelling efflux of air and blood in the alveoli for respiratory purposes, at the same time keeping the fluids in their channels and maintaining a balance in the circulation. And in the absence of a fundamental principle upon which to base the mechanics, it were utterly impossible to do this, as a matter of course. ♦ But by applying this law of pressure and the power of pro- ducing rapid rhythmical changes in pressure to the special circumstances in the structures and functions in the lungs, together with the principle for evolving force in the organism, and the whole is at once made intelligible. The special arrangements that obtain in the aveoli, the manner the walls are hooped in with elastic tissue fibres to the framework in the PHYSIOLOGICAL ANATOMY. 95 lungs, the disposition of the capillary plexuses upon the walls, the residual air for ballooning them so as to obviate friction, the special arrangements in the tracheal system for maintain- ing patency, so as to effect free ingress and egress to the air, together with the numerous muscles and nerves for operating them, the circumstance of suspending the lungs from the upper dorsal vertebrae so as to hang free in the pleural cavi- ties, and entirely disconnected from the ribs, the purport of the pneumogastric and recurrent laryngeal nerves ; finally, the relations which the heart sustains to the lungs, together with the special arrangements in the nerves for coordinating the heart and blood-vascular system with respiration ; all these things are made intelligible ; otherwise are utterly inexpli- cable. A number of others could be readily added, but they will come up as we go along. Concerning Adjustments in the Lungs. — Commencing with the external surface, the first thing to note is the suspension of the lungs from the upper dorsal vertebra*, and clear of all connection with the ribs, so as to hang free in the cavities' of the pleura*. Of course, this fact is impossible of explanation upon any other hypothesis than that of free action in the organs, for which this condition is absolutely essential, enabling them to expand outward and downward during inspiration, and for contracting upward and inward, or toward their roots, during expiration, thereby bringing all the air-cells into active operation, those in the apices with those in the bases of the organs, since all perform work in respiration in proportion to the size of the capillary plexuses. But in the absence of this power of expanding and contracting in the cavities of the pleurse, the apices could not be brought into action, the upper portions of the chest-cavity being comparatively immovable. There must be some easy, natural method for doing this other than obtains by reducing pressure at the sides and bases of the lungs, which would have the effect of aspirating all the air into these localities only, and leaving the apices perfectly useless, even admitting that the old principle for operating the lungs did apply, which by no means can be done. But the cells, by expanding simultaneously, would compel cir- 96 PHYSIOLOGICAL ANATOMY. culation of air to be uniform throughout the lungs, otherwise impossible. Furthermore, this would explain the existence of the pleurae, together with the copious secretions for lubricating the organs so as to obviate friction during the rhythmical expansions and contractions ; otherwise inevitable. Then, again, it would ex- plain the rapid resorption of the pleuritic secretions in order to maintain a balance ; and since they are rapidly poured out, some expeditious and efficacious means must obtain for compel- ling resorption to be in correspondence with secretion for main- taining a balance, otherwise impossible. And nothing could be more admirable than the arrangements that obtain in this respect For example, the lymph channels to these membranes open upon the pulmonic and diaphragmatic surfaces by means of numerous stomata, while a dual force applies for compel- ling them into the channels ; and which is produced during inspiration by the low pressure in the lungs, with high pressure ure in the pleurae, acting simultaneously, so that the best possible conditions obtain during inspiration for pumping the pleuritic secretions into the lymph channels; while during expiration, and the expansion in the diaphragm which this produces, throws open its lymph channels ; at the same time high pressure is produced in the pleurae by the viscera in the abdomen, which are compressed into the chest-cavity under the action of the powerful muscles in the walls, the chest also contracting. Thus, during both inspiration and expiration, a pulling and a pushing force combine for compelling rapid resorption of the pleuritic secretions ; and since they are con- cerned in haematosis as well, being lymphoid, the necessity for such expeditious method for producing circulation in the sacs will at once appear obvious. Of course, the same mechanics apply for removing the morbid collections resulting from pathological changes in the organs. But the action in the lungs may be impeded by adhesive inflammation, which is very common — indeed, is nearly always the case in chronic pleurisy ; hence the occasion for early surgical interference in acute pleurisy accompanied by copious serous effusions, lest the bridles of lymph which are likely to form between the surfaces should become firmly organized and PHYSIOLOGICAL ANATOMY. 97 inhibit the action in the lungs. This action in the lnngs would also explain the friction sonnds in the early stage of acnte pleu- risy, from arrest of the normal secretions and the drying of the membranes which this produces, the to-and-fro movement in the lung as it expands and contracts against the costal pleura giving rise to the friction sounds, or the same precisely as obtains in the early stage of pericarditis, the rhythmical expansions and contractions in the heart causing the opposite surfaces of the pericardial membrane to rub against each other. Last, but not least, it would account for the embarrass- ment to respiration which is produced by pleuritic adhe- sions, and why this should be in proportion to the extent of the adhesions, and most dangerous when occurring at the bases of the lungs or most active portions, as this would inhibit free action in the organs. But should the lungs be passive, as alleged, then the more completely they were under the control of the containing walls the more efficient they would be, as this would compel response to every move- ment in the latter for pumping the air into and out of the organs. On the contrary, however, it dreadfully interferes* with respiration, and these unfortunates breathe with diffi- culty; and when extensive at the bases of the lungs, they perish speedily by asphyxia. It follows that the lungs must be free in the cavity of the pleurae to admit of the rhythmical expansions and contractions in respiration, arid are not "passive bags," to be "pulled open and closed by the action in the external walls," but that they perform an active role. But the argument does not end here, only fairly begins, for overwhelming evidence, a perfect avalanche, is coming. We now turn to the mucous surface. Of course, the sole purpose of respiration is to bring the air and blood into intimate relation for effecting mutual interchange ; consequently, the air must complete the entire journey to the alveoli in order to carry in oxygen and bear out the waste * In a case of acute pleurisy coming under my own observation, occurring in a young man, and suddenly terminating fatally, no other cause of death could be found save recent extensive adhesions at the bases of the lungs ; most exten- sive in the right, but affecting large portions of the left pkura also ; in both. sides the diaphragm was adherent. 98 LUJSTG-ACTI0N ABSOLUTELY NECESSARY. products (inclusive of the foreign matter carried into the organs by the air), and which must be as rapidly removed for maintaining the functions in the lungs. Hence, it is manifest that the ■ tidal air" does not go half -way to the lungs, then stop suddenly against the " residual air" as though this were an impediment and a barrier to further advance, to transact its business with the venous blood as best it can through this obstruction ; at the same time to remove the waste products, since, this would by no means effect the objects sought to be accomplished by the mechanics, and less than this would come short of the scheme in the circulation and make it impossible to carry on the functions in the lungs. Moreover, the very mechanical principle which is involved for pumping air into and out of the lungs must inevitably produce a current through the tracheal system and terminal air-cells, since they expand and contract regularly and rhythmically, synchronous with respi- ration. But we have now to mention a number of facts of a most pressing and urgent nature connected with the functions in the alveoli, which make it absolutely certain that there is such energetic circulation of air through the tracheal system and air-cells, namely : In the first place, carbonic acid, by reason of its weight, tends to accumulate in the alveoli ; and did not some effective means obtain for promptly expelling it, would put an end to respiration very speedily by displacing the oxygen or preventing its ingress. The noxious exhalations which are poured out as waste products in the alveoli, and if not as rapidly removed, would inevitably lead to decomposition and infection of the body, since the animal matter which is contained in them, together with moisture and high tempera- ture in contact with the atmosphere, must lead to rapid decomposition with septic poisoning. Hence, this would in- hibit "stationary air" in the alveoli. In short, stationary air is stagnant air, and the functions in the lungs would not admit of this. And what a commentary this upon the universal appetite for fresh air — its delightful sensations, its exhilarating and revivifying effects ; yet never permitting it to reach the alveoli at all. And were not the statement set up in print, to be read of all men, one would scarcely credit it ; but there it stands, in hideous irony of the beneficence in Nature. But LUNG-ACTION ABSOLUTELY NECESSARY. 99 science can make progress only when the facts are fully and completely ascertained, and this great law of pressure under- lying the organism itself never having been applied to the functions in the lungs methodically, the phenomena could riot possibly be understood ; hence this monstrous statement, not to be believed henceforth and forever in this world of ours. 2. There must be arrangement for maintaining cleanliness in the tracheal system and air-cells by removal of the foreign matter, such as dust, smoke, etc. , borne in upon the tidal air, and which, by the force of gravitation, tend to the alveolar floors, and, mixing with the secretions, would soon form a thick layer of mud upon the capillaries and so inhibit the functions in the lungs, producing asphyxia ; a danger which may be appreciated more readily after reading the statement by Prof. Tyndall,* " that respired air toward the end of ex- piration is strained of all dust particles in the lungs, and is absolutely pure^ referring to that coming from the deeper portions, or the last expired. One may readily imagine, therefore, the amount of deposit which must take place in the lungs from this source, and which must be as rapidly re- moved. But to this must be added the secretions that are poured out upon the surface for lubricating it ; together with the products of inflammatory action — pneumonia, for example — in which the affected air-cells are literally filled up with exudation products and for the time obliterated. Hence^ to be commensurate with this circumstance would require some comprehensive and effective means for expelling them and so relieving the air-cells. Much stress is laid upon the cilia for maintaining cleanli- ness in the lungs; but independent of the fact that these deli- ' cate hairs are totally incapable of performing the amount of work which this involves, the statement would certainly not apply to the alveoli, the place of places where cleanliness should be maintained, since they fade out and disappear alto- gether in the bronchioles. And in this connection we are forced to notice a statement of German origin, which has gone the rounds and would seem to be credited, "that the exuda- tion products in pneumonia are resorbed and eliminated * Fragments of Science, p. 161. D. Appleton & Co , New York. 100 LUNG-ACTION ABSOLUTELY NECESSARY. through the special emunctories," and which is equivalent to saying that the copious septic materials in the alveoli are emptied into the arterial system and sent through the length and breadth of the domain to infect the nervous centres, and form innumerable foci for inflammatory action ; or, in other words, that the road to recovery in pneumonia is by septicaemia, which is preposterous. Ach, Gott ! It is too horrible. It will not do to think about. That Nature would do this thing! That she should sweep the festering alveolar col- lections into the blood-vessels in order to get rid of them, when they are virtually already out of the body, being upon the mucous surface, and for their complete expulsion, by a most short, direct and expeditious route, a most perfect mechanical arrangement obtains, is, to say the least, and putting it mildly, a most extraordinary statement. Perceiving this, therefore, we only mention the circumstance to show how urgent the necessity for a further extension of purely mechan- ical principles in the body in order to make the circumstances in the structures and functions of the organs intelligible. In fine, the collections are pumped out of the alveoli by the rhythmical expansions and contractions in the bronchial tub- ing during respiration, and which are much more energetic than in the alveoli. The tough fibrinous concretions are first detached from the underlying capillaries and more or less dis- integrated by the purulent secretions which they provoke, when they are readily aspirated by the bronchial tubing and expelled thence by cough — a sudden and forced expiration for sweeping out the bronchial collections, upon the same principle precisely as obtains in sneezing for expelling matter irritating the Schneiderian membrane. It is easily understood. Thus, the collections when aspirated into the bronchial tubing by their energetic expansions during the inspiratory efforts, ex- cites cough, which expels them ; the irritation they produce in the bronchial mucous membrane being propagated thence to the medulla oblongata for setting up this reflex action ; a circumstance which is also proven by exciting the bronchial mucous membrane artificially, when cough is readily produced. And it would also explain the short, energetic inspiration ■which precedes cough, since this would have the effect of EXPELLING ALVEOLAK COLLECTIONS. 101 aspirating the collections in the alveoli, while the sndden forced expiratory effort, which follows immediately after, should have the effect of expelling them from the body. The anatomical dispositions are very perfect ; could not be better. For example, the bronchi are surrounded by neighboring alveoli, which are not only in contact with the tubing, but are actually incorporated in the walls for compelling them to re- spond to the movements in the tubing during respiration (Fig. 2 ,f, , c), which is also the result of systole in the vessels, show- ing conclusively that they are expressions of the same thing. Thus, all the characteristic elements in the arterial tracings are reproduced in the tracings of blood-pressure, the oscilla- tions in wThich correspond with the rhythmical expansions and contractions taking place in the vessels which alternate with the actions in the heart, inclusive, of course, of the movements synchronous with respiration. In fine, the mean pressure in the vessels is produced by the action in the heart, but the oscillations in pressure are mainly produced by the vessels themselves, which have adjustment with the heart and with the lungs, expanding and contracting upon their contents to meet the special emergencies in the functions in these organs ; while the rich nervous plexuses which emboss the vessels con- AUTOMATISM IN THE VESSELS DEMONSTRATED. 147 necting them with the cardiac and respiratory centres serve for coordinating and unifying the actions throughout, at the same time also serving to produce the local actions in response to special stimulus. Hence the existence of this enormous web of nerves. But to this must be added the evidence which is furnished in the tracings produced by changes in volume (Fig. 5 1 ), in which entire organs, inclusive of the whole soft tissues in the body, expand and contract regularly and rhythmically syn- chronous with the actions in the heart and in the lungs. And to say that this also is produced by the action in the heart is perfectly absurd. Some idea of the force in the arterial pulsations may be had by watching the to-and-fro movements in the foot when the legs are crossed at the knees in the sitting posture, the foot of the upper limb riding up and down with every rhythm in the vessels. To say that the heart produces this action also, is utterly incredible. Moreover, this action may be seen in an- other form in the fierce pulsations which occur in the local vessels in inflammatory processes, though the heart may be beating as usual, and which in itself is ample proof of automatism in the vessels ; otherwise is inexplicable. The pul- sations which occur in the ears of a rabbit and wings of a bat are not synchronous with the action in the heart, thereby show- . ing conclusively independent action in the vessels themselves, furnishing incontrovertible proof of this circumstance. Concluding this class of evidence, we may mention the pul- sations occurring in the umbilical cord, which are not synchro- nous with either the maternal or foetal heart, moreover occur after connection is severed, and which furnishes absolute proof in itself of automatism in the vessels. Last, but not least by any means, are the facts in development, showing how a complex circulation is carried on, with regular rhythmical expansions and contractions taking place in the vessels, in the entire absence of a heart for producing them; notably in worms. The point we wish to make in this connection is, that the ani- mal circulation is at first carried on by the vessels only (inclu- sive, of course, of the actions in the walls of the body and the molecular movements), and that the heart comes into the vascu- 148 PHYSIOLOGICAL ANATOAIY. . lar system with progress in development for increasing circu- lation simply ; being itself a differentiation in the vessels for this purpose only, and not to displace or substitute the action in the vessels, which can by no means be done, the local actions themselves inhibiting it, the question being one of increasing force in the circulation simply ; and which is done not by the differentiation of this central force-pump only, but also by innumerable muscles and nerves to the vessels them- selves; the two being always in correspondence, the vessels developing as the heart is being developed, and growing pari passu with each other. And which holds true in embryogeny as well, the nutritive processes building up the vessels contem- poraneously with the heart, the two going on together. More- over, they are fundamentally the same in structure, consisting of an inner, a middle and an external layer ; or a serous, mus- cular and elastic or fibrous tunic (which in the heart is converted into a pericardial membrane), thereby enabling them to expand and contract the same as the heart, which the functions call for. In further proof of this automa- tism in the vessels, we might mention also the pulsa- tions occurring in the post-caval, axillary and iliac veins in JBatrachia, which are not synchronous with the action in the heart ; also the action in the lymph-hearts, which are not syn- chronous with the pulsations in the heart ; nay, not even with one another, each seemingly possessing an independent action So, then, this matter of automatism in the vessels rests upon incontrovertible evidence, anatomical and physiological ; in fact, everything is in accord with this circumstance, the law in the circulation also compelling it. But the matter is not yet fully summed up ; turn we to the special anatomy in the organs, to see how this accords with the other phenomena, or, as means to ends, for producing the work involved in the tracings, the rhythmical expansions and contractions in the walls of the vessels indicated by them. Descriptive Anatomy.— 1. The arteries are very muscular organs, the small arteries nearly all muscles (Fig. 4G) * *Tlie dark lines show the longitudinal muscles. PHYSIOLOGICAL ANATOMY. l-i9 If the vessels are conduits simply, what then is the office of these numerous muscles, seeing that muscles and nerves (so many nerves, too, to the vessels) are physiological adjust- ments for performing work ; whether it relates to circulation or the voluntary movements it is all the same, force being pro- Pig. 46. — Transverse Section of an Artery from a Vertical Section of the Skin of a Guinea Pig. — Klein, a, lumen of the vessel ; 6, endothelium seen in profile ; c, intima ; d, circular muscles ; e, adventitia ; /, cellular elements of adventitia. (Oc. 3 ; obj. 7.) Fig. 47. — Longitudinal Section of a Branch of the Pulmonary Artery, from the Lung of a Guinea Pig. — Klein, a, intima ; 6, circular muscular fibres cut across ; c, adven- titia, (Oc. 3 ; obj. 7.) ]50 PHYSIOLOGICAL ANATOMY. • duced by this means, while the energy is determined by the numbers of the muscles and nerves '. 2. Why should the muscles in the vessels be nearly all cir- cular, extending round the vessel '. (Fig. 47. b.) And since muscles elongate and shorten, or expand and Contract when in action, would not this necessarily expand and contract the lumen correspondingly, thereby producing the rhythmical changes of pressure upon the blood for speeding it through the channels in the manner as alleged, the vessels being coordinated with the heart and the lungs by means of the nerves, which emboss them % It could not be otherwise, in the very nature of things, seeing that the muscles expand and contract, and this cannot be doubted for a single moment even. In short, the arrangement of the muscles in the vessels is the same as in the dermo-muscular tube in the leech, which expands enor- mously (Fig. 17), only that the longitudinal muscles are more numerous for effecting elongation and contraction of the body, for which it possesses great powers ; whereas, in the vessels, the object is to effect expansion and contraction of the lumen for producing the changes of pressure upon the blood ; while the less numerous longitudinal muscles enable a degree of short- ening and elongation as well, producing the so-called locomo- tion in the vessels (Fig. 48), the effect of elongation simul- taneously with lateral expansion, together with the subsequent contraction which sets in, also accounting for the retraction of the vessel within the sheath after division, as occurs in ampu- tations, for example. The movements connected with the systemic circulation would include the actions for producing a norm in arterial pressure, the rhythmical changes in pressure with inspiration and expiration, finally with the actions in the heart itself, the vessels expanding during the systole and contracting during diastole. But, in addition to this, the local vessels expand and contract for increasing and diminishing the lumen, in response to special stimulus in the organs, whereby the local circulation is increased or decreased correspondingly, a matter determined by the local ganglia or mind centres, which, as a rule, are located at the points where the branches are given off from the main stem. And the whole being connected with the PHYSIOLOGICAL ANATOMY. 151 medulla oblongata by means of the vaso-motor centre, coordi- nation with respiration and the action in the heart is readily effected ; at the same time a norm in pressure is main- tained. Thus, these two important anatomical facts in the muscles and nerves to the vessels have easy and natural ex- planation 3. Last, but not least, we have to mention the progressive increase in the numbers of the muscles in the arterial sys- tem from the heart to the tissue-territory (Fig. 49). How is this circumstance to be accounted for % According to present theory, which makes the heart the Fig. 48. — Elongation and Curvature of an Artery in Pulsation.— Dalton. force in the circulation, this arrangement of the muscles is totally inexplicable, since the effect would be to place ob- struction in the roadway of the blood, and hinder in place of assisting the action in the heart ; and, considering the number of the muscles, it must necessarily involve pro- digious strain to the heart itself for overcoming the resistance, admitting, for the sake of the argument, it were capable of do- ing this, which can by no means be done. The vessels being always full, arterial pressure only varying, it follows that in order to compel more blood into the vessels, this force would have to be overcome by the heart, which is utterly impossible. Then, again, conservation of force, and of the very blood itself, would inhibit such rude mechanics, ignoring altogether strain to the heart, which, for obvious reasons, cannot be i52 PHYSTOLOGICAL ANATOMY. done. And not these only, but the sudden force and energy in the very leap of the pulse would alike have to be explained by cardiac action. Last, but not least, the danger to the blood itself should it be used as a wedge, so to speak, to be driven into the vessels by the sledge- hammer strokes of a central cardiac engine for forcing them open. Either the delicate blood-corpuscles would go to pieces in the midst of this rude force, else the aorta itself would burst, admitting the heart were capable of per- forming the work assigned it, and that the vast numbers of circular muscles and elastic tissue-fibres could be pulled into forcible extension by this means. It is coarse and brutal to the last degree, and extremely primitive. But the haemal me- chanics is of a much higher order, nursing the blood and con- serving the heart and vessels by reducing friction and resist- ance to a minimum, and which is done by dividing the force for effecting circulation into a vis a f route and a vis a tergo, acting in concert and simultaneously, or a, pulling and a, push- ing force combined ; the former produced by the arterial dias- tole, the latter by the cardiac systole, working together har- moniously and in conformity with the law underlying the* organism, the blood flowing relatively from high to low pressure. And with the bases of the arterial pyramids in the tissues and the apices at the heart (Fig. 49), this action in the vessels would inevitably have that effect upon the blood during the cardiac systole. And since the pressure in the ventricle during systole amounts only to about 6 oz. (mercury), while that in the arteries falls below this, it follows that during arterial diastole the blood would flow from higl to low pressure, pressure falling from the heart to the tissue-territories where expansion is greatest, being the widest portions of the pyra- mids (Fig. 42, L, L) ; and by thus sucking the blood, relieving work at the heart in proportion ; while the nervous plexuses embossing the heart and the vessels serve for coordinating the actions, as before remarked. And in regard to these nerves, too, what possible explanation can be found in this old theory for their presence also, any more than for the muscles ? None whatever, save to produce contraction in the vessels, which PHYSIOLOGICAL ANATOMY. 153 should hinder in place of assisting the action in the heart. But they "relax" the vessels also! Ah! that concedes the matter fully, and no more need be said, for relaxation means expansion ; and the two being coordinated in the functions produce the phenomena in the tracings. And since expansion Fig. 49. — An Ideal Diagram of the Arterial System, showing progressive increase of the muscles from the heart to the tissue territory. L, L, upper and lower arterial pyra- mids ; a, left ventricle and auricle ; p, p, right and left pulmonary veins as they debouch in the auricle ; n, longitudinal section of right auricle and ventricle, show- ing inter- ventricular and auricular septum ; B, B, walls of the vessels, representing the progressive increase of the muscles from the heart to the tissue territory. and contraction are correlated forces in Nature, the whole mechanics in the animal circulation is at once laid bare under the white light which is furnished in the law underlying the ]54 REFLUX IN THE CAPILLAKIES IMPOSSIBLE. organism. But should the arteries expand, would not this produce reflux in the capillaries and venous system \ No ; it would not produce reflux in the capillaries and venous system, for the following unanswerable reasons inhibiting it, notably : 1. Pressure in the arteries — thanks (!) to the force in the heart — is ever higher than in the capillaries and venous system; hence re- flux in the latter is made impossible. 2. Expansion in the vessels is from the heart to the tissue-territories, while the blood keeps pace with it, flowing into the vessels as rapidly as ex- pansion is effected ; and even in excess of this, transmitting some of the force in the heart to the walls during the systole, thus producing an increase of pressure during this time, which is still further augmented by the systole in the vessels, which sets in at the end of the cardiac systole, the one running into the other, the same as in the respiratory rhythms, with which the vessels are coordinated, as in the heart, the principle being the same ; while reflux in the arteries is obviated by the valves at the root of the aorta and pulmonary arteries, so that reflux in the arterial, capillary or venous systems cannot possibly occur ; the only thing being venous stasis in the systemic capillaries from damming of the blood at the right side of the heart by obstruct- ing circulation in the lungs, the venous system filling back to the capillaries. And so far as the argument is concerned, we might safely rest the case here, were it not incumbent upon us to carry the matter further by explaining all the phenomena, anatomical and physiological, appertaining to the vessels ; and this a true theory of the circulation should be capable of doing, else it is not the true theory, but a false. And by apply- ing this crucial test to the Harveian, its utter fallacy will at once be seen, for it would leave all these matters unex- plained and inexplicable ; and the beautiful adjustments that obtain in the vessels and in the heart for producing work in the circulation would be perfectly meaningless. But by the true theory it is all brought out fully and elucidated so that everything is seen to be just as it should be to meet the require- ments in the functions and the ends sought to be accomplished, while the enormous resources in Xature and her matchless handiwork receive additional emphasis, inspiring a feeling of awe and reverence in the mind unspeakable ! AUTONOMY IN THE VESSELS INEVITABLE. 155 Proceeding with the anatomy, we come next to the thick elastic coat in the vessels The animal circulation being based upon pressure, for increasing pressure in the arteries it calls for this thick elastic coat for producing it, otherwise it were impossible to effect it (as is seen in the case of the veins), the vessels giving way under it ; and which would also explain the circumstance of the relative thickness of the elastic coat in the aorta, together with its progressive increase as the heart is i approached, where pressure is greatest, the artery at this point being nearly all elastic fibres. For maintaining high pressure in the arteries, then, is the explanation of this strong elastic coat in the vessels, the whole matter relating to pressure ; while the high pressure which is produced in the arteries by the action in the ventricles serves for increasing the capillary circulation, at the same time that it functions as the vis a tergo to the venous system for compelling this blood more rapidly toward the lungs, the arteries contracting and expand- ing synchronous with respiration for increasing the action, and for compelling the blood more rapidly through the lungs dur- ing inspiration and expiration, as before remarked. Concerning the Local Actions. — Finally, we come to the local actions in the vessels in connection with the multitudi- nous functions in the body, and which vary from moment to moment, so that perfect uniformity in the circulation nowhere obtains, and is utterly impossible. Now, then, for producing these actions, it calls for automatism ia the vessels in order to enable them to respond to stimulus so as to increase or decrease the circulation, as the case may be. And in the midst of this overwhelming avalanche of facts, what is to become of that old monistic theory of cardiac action only? — it is utterly lost, swallowed up, disappearing from sight in the midst of the myriad phenomena. It need not detain us; one or two illustrative cases will serve. Thus, when food is passing into the stomach its pres- ence produces enormous afflux of arterial blood in the organ, the vast capillary network in the gastric mucous membrane (Figs. 64, 65) springing open at once, for compelling blood into the parts in the measure of the physiological require- ments in the glandular structures and for increasing absorp- 156 AUTONOMY IN THE VESSELS INEVITABLE. tion, at the same time the biliary and pancreatic secretions are increased correspondingly, which is done by springing open the vascular feeders in the separate arteries of the coeliac axis, while this in turn has regulation by the amount of food ingested, diminishing with the gradual absorption and removal of the gas- tric contents. And each organ, by having a separate feeder (Fig. 110), controlled by the local nerves and ganglia (Fig. 109), is thus enabled to command all the blood that is needed for effect- ing the functional processes without interfering with the general circulation, which must not be done. K ay, more than this, each group of cells is enabled, by the separate branches given off by the common feeder to the organ, to command the blood they need in the special exigencies arising in the local actions, so that the organ as a whole and in its several parts may com- mand the blood-suppiy in the measure of the requirements. And so, likewise, down the whole intestinal canal, each and every portion, by means of the separate feeders to them repre- sented in the trunks and numerous branches of the superior and inferior mesenteric arteries (Figs. Ill, 112), may com- mand, by means of the special nerves and ganglia, the amount of blood they need without interfering with any other por- tion, so that perfect independence of action is maintained. Well, while all this is going on in digestion, the heart beats as usual, and as though there were no such thing as digestive processes, and all the multitudinous arrangements for expe- diting and controlling the flow of blood into the organs : moreover, is utterly incapable of effecting the actions, requiring automatism in the vessels themselves in order to accomplish it. But the heart, by maintaining pressure in the arterial system, which tends to fall by reason of these depletions, does subserve important uses, the vaso-motor system also contributing by con- tracting them in proportion, and thus maintaining pressure, which is essential for increasing the local actions by causing instantaneous flow into the capillaries the moment they ex- pand, at the same time maintaining the other actions in the body which the scheme calls for. Take another case — the kidneys, for example. Upon occa- sion an enormous flow of urine takes place. Well, since this is drawn directly from the blood through the secretory actions NERVOUS SUPPLY TO THE VESSELS. 157 in the organs, it follows that there must be an increased supply of blood in the parts in order to effect it. And how is it pos- sible to command this increased supply of blood save by spring- ing open the renal vessels correspondingly ? It all comes from the blood, and there must be increase of this in the organs for producing it, the amount being determined by lumen of the vessels, which the local nervous ganglia regulate by means of the nerves extending over and literally embossing them (Fig. 109, 9, G). At the same time, the vessels, arteries and veins are very muscular And there is no nervous plexus in the body richer in nerves and nervous ganglia than the renal, save the solar plexus itself, the solar centre of the intestinal mechanics, Fig. 50. — Ramification of Nerves and Termination in the Muscular Tunic of a Small Artery of a Frog. — Arnold. of which it forms a part, being immediately contiguous to it (Fig. 109, G) ; thereby showing the relative importance of the renal functions for maintaining a balance in the organism through the excretory functions in these organs. But in the absence of the power to expand and contract the vessels, all this would be meaningless. As it is, everything is in corre- spondence for promoting the ends in view. Nervous Supply to the Vessels. — Finally, we come to the nerv- ous supply to the vessels, with the mode of termination in the sarcous elements for effecting the actions spoken of. According ]58 NEKV0US SUPPLY TO THE VESSELS. to the exhaustive researches of Arnold, the nervous twigs in un- striped muscles consist partly of medullated and partly of non- medullated fibres, in varying proportions, penetrating to the nucleus of the muscle cell in the form of a fine terminal fila- ment, and ending probably in the nucleolus. Externally, in the connective-tissue covering the muscle, these nerves are arranged in the form of a wide-meshed network, in which, as Beale has pointed out, ganglion cells are to be found at cer- tain points in the muscles of the vascular system (Frey). To this the name ' ' ground plexus' ' has been given. From this are given off the nerves which penetrate between the layers of muscles to form the ' ' intermediate network' ' (Fig. 50), which lies immediately upon or between the muscular layers ; while from this again a series of fibres are given off which penetrate between the muscle fibres to form a new network, "intra- muscular," surrounding the muscle cells, from which dark straight fibres of extreme fineness penetrate into the Cells, and, advancing to the nucleus, terminate in the nucleolus (Franken- hauser). The number of terminal filaments which enter any one muscle cell corresponds with the number of granules occurring in the nucleus (Frey). According to Arnold, these fibrillse leave the nucleoli again in the opposite direction, and after having traversed the nucleus and body of the cell, unite once more with the intra-muscular network. Finally, a set of pale fibres proceed directly from the "ground plexus" to the muscle cells, forming a direct connection between them. Now, then, what can be the purpose of the ganglion cells in the "ground plexus" and the intricate nervous arrangements which obtain in arterial muscles for producing molecular action in the cells other than to effect the actions spoken of \ Seeing also that an intimate connection subsists between them and the plexuses embossing the vessels, connecting them with the central nervous system. It is needless to extend the matter. This brings us to the remaining element in the arterial tracings, notably, dicrotism ; but that will require a chapter to itself, involving the action in the capillaries in connection with res- piration in the tissues. CHAPTER VIII. RESPIRATION IN THE TISSUES AND THE ACTION OF THE CAPILL ABIES IN CONNECTION THEREWITH. Two Respiratory Movements Going on at the Same Time in the Body, one in the Lungs, the other in the Tissues — The Force for Producing the Movements Propagated from the Medulla Oblongata and Respiratory Centre — The Composite Character in Arterial Tracings Readily Explained — Rhythmical Expansions and Contractions in the Tissues Synchronous with the Actions in the Lungs, Heart, Arteries and Capillaries — The Waves Superposed Upon One Another in the Order Named, or the Cardo- Arterial Upon the Respiratory, and the Capillary or Dicrotic Waves Upon the Cardo- Arterial — Capillary Action the Source of Dicrotism — Mode of Demonstrating this Circumstance — The Action in the Capillaries Producing a Current Into and Out of the Tissue-Interstices — Relations of the Cell-Brood to this Circulation — Nervous Apparatus for Connecting Them with the Capillaries and Central Ner- vous System for Increasing and Diminishing the Local Circulation, with the Exi- gencies in the Functions — Mechanics in Blushing — Explanation for Arrest of Arterial Pulsations Upon the Distal Side in Aneurisms — Action in the Venous System — Functions of the Muscles and Nerves in Veins — The Relations they Sustain to Respiration — Explanation for the Great Volume of Venous Blood and the Slowness in this Circulation — Also for the Motion in the Brain Synchronous with Respiration. Finally, in order to fully interpret the phenomena in arterial tracings, it will be necessary to consider them in connection with the capillary circulation and the respiration in the tissues. In, short, there are two respiratory movements going on at the same time in the body : One in the lungs, the other in the tissues, and which answer to the two poles in the floral circulation; while the heart and vessels function as a carrier between them, expanding and contracting upon the fluids for increasing circulation in the two poles, while the force for compelling these actions is transmitted over the vessels from the central nervous system by means of the nervous plexuses which emboss them. The result is the pro- duction of the composite character in the arterial tracings, or the existence of respiratory, cardo -arterial and dicrotic waves ; and which are superposed one upon the other in the order named, or the respiratory by the cardo-arterial, and the latter 160 RESPIRATION IN THE TISSUES. by the capillary or dicrotic waves, which represent the respi- ratory action taking place in the tissues. It is all plain enough and readily understood, the actions being simply throbbed over the vessels as the common carrier between the two poles of the circulation from the medulla oblongata, in which the nerves converge for coordinating and unifying the actions throughout, which the scheme calls for. This being the case, of course there should be a means of proving and demonstrating the fact by showing the following circumstances : First, That the respiratory waves, or the waves produced by respiration in the lungs, reach and pervade the tissue-terri- tory. Second, That the cardo-arterial loaves, or pulsations, reach and pervade the tissue-territory. Third, That dicrotism, so-called, is the capillary movement superposed upon the cardo-arterial. Thanks (!) to the distinguished physiologist and experimen- talist at Paris, we find the evidence ready to our hand : It consists in inclosing the hand in a glass jar filled with water, made air-tight over the top, and so constructed as to cause the oscillations it produces in the water to be transmitted to the lever of a sphygmograph for registering the result (Pig. 51).* It produces the following tracings (Fig. 52, V) : f In the same cut the tracings are contrasted with the tracings produced by the arteries (C), but for a different purpose from the present, the author being under the impression that they are produced by the action in the heart, alleging the same for the arterial tracings, making this organ the force in the circulation, which cannot be thought of for a single moment, for the reasons already given. We will begin with respiration, as this is the basis, so to speak, of animal life, beiag the pumping action for compelling the commerce in the organism with which the vascular system connects for distributing it through the tissues, as before re- * La Methode Graphique dans les Sciences Experimental, et Principale- ment en Pbysiologie et en Medecine. Par E. J. Marey, Professeur au College de France, Membre de l'Acadernie de Medecine. Fig. 327. t Ibid Fig. 328. RESPIRATION IN '1HK TISSUES. 161 marked. Now, then, we have this great movement, which pervades the entire organism from centre to circumference, Fig. 51.— Apparatus for Inscribing the Changes of Volume in the Hand. The membrane which traverses the fluid is rendered immovable by a metallic plate ; while the oscillations which are produced in the water are transmitted through the bulb and vertical tube to the lever of the sphygmograph by means of air- — Marey. Fig. 53.— Sphygmographic Tracings, showing the undulations in the vessels and tissues synchronous with respiration. C, respiratory rhythms in the arteries ; A, crest of a wave ; C, trough of a wave. V, respiratory rhythms in the tissues, smaller, but very apparent ; b, trough of a respiratory wave in the tissues, corresponding with the crest (A) to the respiratory wave in the arteries, which arrives later ; £>, crest of a respiratory wave in the tissues, which corresponds with the trough (C) of the respiratory wave in the arteries which had passed into the tissues. 1G2 RESPIRATION IN THE TISSUES. registered in the arterial tracings in the large undulations which occur in it (Fig. 52, C, A). Two and one-half such waves occur in the tracings, the one at the right-hand side of the figure being cut off. And the same circumstance also presents in the tissue tracings (V), only that they are smaller and arrive later, having to pass over the arteries in order to reach the tissues, the nerves lying upon the walls of the vessels. As a result of this circumstance, therefore, the crest (A) of the respiratory waves in the arteries corresponds with the trough (b) of the respiratory waves in the tissues, and vice versa (C, D). In other words, the same number of res- piratory actions occur in the tissues as in the arteries to the very fractional portions of the waves, and nothing could be more conclusive of respiratory action in the tissues than this very circumstance. Prof. Marey, however, conceiving it to be due to the action in the heart, has drawn perpendicular lines at certain points through the upper and lower tracings, in order to show correspondence, as he thinks, between the action in ih e heart and the changes of volume in the hand, as cause and effect. But we fail to perceive it in this light, for the rea- sons already given. It is not so simple as this, but highly complex, the result of several actions blended together. It will not answer at all. What is to be done with the correspondence between the large undulations — the two whole and the fractional portions of the respiratory waves — which occur in both tracings, since there is exact correspondence ; only they are smaller in the tissues, as a matter of course, and arrive later, which is also a matter of course. Then there are sixteen smaller waves, which are superposed upon the larger, indenting them like the teeth in a saw, which answer to the action in the heart and arteries, the same number precisely occurring in both tracings, so that correspondence here is also complete — impossible to make it more so. Well, what is to be done with this correspondence % as it all must be explained and satisfactorily accounted for ; else the theory is false. These smaller undulations occur all along the surface of the respiratory waves, at the crest (A), at the sides, and in the very trough (C) itself, in regular order and succession ; the same applying for both tracings. Then, AKKESTING DICROTISM. 163 again, there are four of these to each of the billows, which correspond with the relative frequency of the respiratory and cardiac rhythms, showing conclusively that the one is respiratory, the other cardiac, or, rather, cardo-arterial, being produced by the united actions of the heart and arteries. The action in the heart, forsooth ! There is more here than is ex- plicable by the action in the heart. It cannot produce the res- piratory undulations in the arteries, and why should it pro- duce the corresponding undulations in the tissues % It follows that the respiratory waves, as well as the waves produced by cardo-arterial movement, pervade the tissues, the latter being superposed, so to speak, upon the former, giving rise to the serrated appearance in the respiratory waves. But we have still smaller waves, which in turn are superposed upon the arterial, producing the appearance known as dicrotism, and indenting these as the arterial the respiratory, and which also present in both the tracings, bat are more distinct in the lower ( V) ; and which, also, must be accounted for with the others. Concerning Dicrotism. — The very fact that dicrotism is more pronounced in the tissue tracings (Fig. 52, v) is of itself suggestive of capillary action as its source, and that it is ac- tually produced by the action in the capillaries is also easily proven by simply arresting the action in these vessels when dicrotism promptly disappears, but re-appearing again with restoration of capillary action, at once showing the relations they sustain to each other. This object is attained by dis- tending the vessels with venous blood, and so preventing their action ; while the action is reestablished again by reliev- ing them of the blood. Thus, with the hand in the registering apparatus as previously (Fig. 5] ), a constricting band was placed above the elbow sufficient to arrest the venous blood only, and after waiting a short interval for the blood to accumulate in the hand, was again relaxed. When suddenly and forcibly applied and as suddenly relaxed, it produced the upper trac- ing (Fig. 53) ;* when slowly applied and slowly relaxed, the lower. * (Ibid, Fig. 330.) It is proper to remark, in this connection, that Professor Marey did not have the present purpose in his mind when he made this experi- ment, but we thank him all the same for the important contribution to science. 16-i ARRESTING DICROTISM It will be seen by the upper tracing that when the venous blood is entirely arrested, dicrotism promptly disappears ; nevertheless, the arterial movements corresponding with the action in the heart are well pronounced, dicrotism only disap- pearing ; doing so almost at once after the veins are constricted. And this shows that it is due to the choking of the capillaries by the damming of venous blood in them, preventing their action. At least, this would account for the circumstance. This is also corroborated by the second tracing, in which the blood was not entirely arrested, but nearly so toward the middle or summit of the tracing, where dicrotism disappears momentarily only, showing some action still left in the capil- laries. In other words, the rhythms in the large vessels con- tinue and are well pronounced, but dicrotism disappears. The sudden, almost perpendicular, fall in the upper curve, which was due to the energetic contraction in the capillaries and veins, produced by the venosity of the blood, which acts as a stimulus, will give some idea of the force in these vessels, which should not be lost sight of in the mechanics of circulation, at once show- ing that the force is available in the circulation by coordinating the capillaries and veins with respiration, as dcfes actually occur ; moreover, is fully proven by the tissue-tracings (Fig. 52, V). In other words, the same principle precisely obtains for increasing circulation in the capillaries and veins as in the lungs, heart and arteries — namely, by rhythmical changes in pressure ; while the force is propagated from the medulla oblongata by means of the nerves, connecting them with the respiratory centre (Fig. 54),* the same as in the other cases ; since this is necessary for producing continuity in force for maintaining an uninterrupted current of the blood in the round of the circulation, in the measure of the physiological require- ments, otherwise impossible. It is plain enough. The damming of the venous blood in the capillaries by dis- tending them must inevitably choke the pumping action, the blood being unable to escape by reason of the ligature, while the energy with which they contract to force out the blood is seen in the sudden fall of the upper curve the moment the ligature is relaxed. * Handbook for the Physiological Laboratory, plate xxxvi. Burd on -Sander- sou, etc. ARRESTING- DICE0TI5M. 165 3 err- • § « cr o © ^ II' CO "1 «. M2 3 3 3 a" rt r* a -x el- CO d s' B da *2 2 St1 ^ 1 o <*■ o CD ^ 8 ■*- o 5* e ° e+ O J-h CD I" Is d p- P 1 §1 d- >-t cd p d o CD B C? » & d- * >o »d 166 DICROTISM DUE TO CAPILLARY ACTION. When gradually relaxed, the escape of blood is, of course, in correspondence ; hence the difference in the curves of the two tracings. It is not produced by the force in the heart, as the eminent Frenchman conceives ; but the force is upon the ground where the work is done, and in the very walls of the vessels themselves, which regulate their own circulation. The heart is too far removed for this work, were not the principle itself wrong. The pith of the whole matter being Fig. 54.— Horizontal Section of Tongue of Frog Treated with Chloride of Gold, showing the distribution of non-medullated nerve fibres to a capillary blood-vessel, a, capil- lary vessel ; b, coarse non-medullated nerve fibres ; c and d, fine non-medullated nerve fibres forming a plexus which surrounds the vessel like a sheath ; d, non- medullated nerve fibres in the wall of the vessel. (Oc, 3 ; obj., 8.)— Klein. that the tissues respire for maintaining the life that is in them and for increasing their activities, and they must con- nect with the respiratory centre and the action in the lungs in order to command the oxygen that is needed for increasing metabolism in the measure of the requirements, respiration in consequence readily rising and falling with the swell in the activities. And the force for effecting this action in the capil- laries being propagated over the vascular lines from the me- dulla oblongata would easily account for dicrotism in the DICROTISM DUE TO CAPILLARY ACTION. 167 heart and arterial system ; and why this should be more pro- nounced with the increase of venosity in the blood, for this makes the demands in the cell-brood more imperious, at the same time it acts as a stimulus to the nervous centres. It would not do, then, to have this important link in the vas- cular chain neglected, as it would involve failure to all the rest. In fine, the large undulations which answer to the pump- ing action in the lungs are let down, as it were, in stages till it meets the finer actions in the capillaries, and so passing on into the venous system, while the whole is intimately con- nected by means of the nerves extending over them for pro- ducing an uninterrupted flow of blood between the lungs and cell-brood (the two poles in the circulation), the cells respir- ing through the lungs, as it were, by means of the arteries and veins which bring in the oxygen and carry out carbonic acid, or upon the same principle precisely as obtains in the embryo, which breathes through the placenta by means of the um- bilical arteries and vein, only that in the latter there is still greater removal from the environment or source of supplies. Still, the principle is the same in both, and the mechanics must connect through and through in order to accomplish it. It would require that all the parts should be coordinated in the vascular chain in order to produce and unify the universal pumping actions for increasing circulation commensurate with the physiological requirements, and dicrotism must take its place in the march of the phenomena, at the same time it shows the interdependence subsisting between them and the common relation they sustain to the law underlying the organ- ism, the whole performing in harmonious concert under action of the nervous forces radiating from the solar centre of the organism. So, then, we can readily understand why the capil- lary or dicrotic waves should announce themselves in the tissue tracings, appearing and disappearing with the relaxing and tightening of the ligature which relieves or chokes the capil- laries, as the case may be. In this manner, then, that vexed problem in experimental physiology has easy and natural solution, dicrotism falling into line at the proper time and place with the other phenomena, leaving nothing to explain, which a true theory of the circulation would naturally do. 118 DICROTISM DUE TO CAPILLARS ACTION. Another Mode of Proving Capillary Action. — Another mode, the very opposite of this, obtains for proving the action in the capillaries as a potential and independent factor in the circulation, without which neither the systemic nor local cir- culation could be made commensurate with the physiological requirements, and animal life would have arrest at the flora. It consists in arresting the flow of blood in the main arterial trunk or feeder for the limb, but leaving the veins open ; and by thus cutting off the force in the left ventricle, to throw the burden of the tissue circulation upon the local vessels them- selves, which should give us some idea of the force in the local vessels for compelling circulation. The same instrument answers for making the tissue tracings as in the preceding, there being no other way of doing it, while the evidence it furnishes is equally conclusive. Of course, compressing the main artery to the limb at once puts an end to all the elements of rhythmic movement in the tracings, the cardo-arterial with the rest (Fig. 55, C, CY/), the uninterrupted flow of blood in the vessels being essential for their development. The point we wish to make, however, is that the hand immediately shrinks in volume, which the lever promptly registers in the low depres- sion (C, C) in the curve of the tissue tracings, and this is produced by contraction in the vessels, driving the blood toward the heart and lungs ; and which proves incontro- vertibly an independent action in the vessels themselves. iSo, then, the force to the tissue circulation is not in the heart, which singly assists it, the main force being actually upon the ground where the work is done, in the walls of the vessels themselves, which regulate their own circulation, and must do so in order to maintain autonomy in the tissues, which is essential to existence. The sudden, perpendicular leap made in the tissue tracings (a') when arterial compression is relieved, is the product of the combined action in the vessels, aided, of course, by the press- ure in the arterial system, compelling the blood into the vessels with the energy of expansile action ; and which soon restores the normal rhythm in the vessels and the volume of the hand, indicated by the rise in the curve of the tissue trac- ings, sending it above the horizontal line, and the reappear- THE FOliCii IN THE TISSUES. 169 170 THE FORCE IN THE TISSUES. ance of dicrotism and arterial movement. And that it is produced by the action in the vessels in the manner as stated is fully proven by the straight, perpendicular line (c'), which answers to diastole in the vessels, and which we have seen the heart, of itself, is utterly incapable of pro- ducing unassisted by the action in the vessels, requiring expansile action in the vessels themselves in order to effect it. At the same time, the over-distension which this pro- duces in the capillaries, the blood rushing into them from the pressure in the arterial system, tends momentarily to choke the action ; hence, the small and imperfect rhythms immediately succeeding the diastole. Furthermore, we know that contraction must possess its equivalent in expansion, so that the previous contraction in the vessels must have its representation in this expansile effort, the one involving the other, expansion and contraction being correlated forces. Moreover, we have the same circumstance illustrated in blush- ing, in which there had been no previous contraction from anaemia, the vessels suddenly expanding under the nerv- ous force pouring into them from the central nervous system, the blood rushing into them instantaneously under the press- ure in the arterial system, producing the characteristic color- ing of the skin, followed promptly by energetic contraction, producing the succeeding blanching of the parts from the anaemia this produces. So, then, there can be no doubt what- ever of an independent action in the capillaries ; otherwise, these actions would be meaningless. Finally, we have to note the low, flat, faint undulations, which answer to the rhythm in the arteries, still remaining in the tissue tracings, notwith- standing the occlusion of the brachial artery above the elbow, and which marks the effort in the vessels to perform the normal functions inherent in them. But in the absence of the blood for filling them pari passu with expansion, as in the case of the air when excluded from the lungs, of course they cannot expand, showing the effort to do so only in these indistinct and faint undulations. But this also subserves im- portant uses by promoting the collateral circulation in the anastomosing vessels, producing a suction-force upon the blood, the connecting capillaries expanding under the nerv- INSPIRATORY ACTION. 171 ous force pouring into them, and the pressure in the ar- terial system, which rapidly restores the normal circulation — the one, the vis a f route, the other, the ms a tergo, acting simul- taneously. In fine, it is the tremendous effort which the tissues make to respire when the supplies are cut off, threaten- ing asphyxia, and in which everything is brought to bear for expanding and filling the vessels with arterial blood. Of course, any circumstance which should prevent the flow of blood through the arteries would also be reflected in the tissue tracings, since this would inhibit afflux of blood, which is essential for filling the vessels pari passu with expansioD, in order to effect expansion ; otherwise impossible. In other words, the capillaries cannot expand unless the blood flows into them simultaneously, since it would require pro- digious force to effect it in the absence of the blood, involv- ing the production of a vacuum throughout the whole affected capillary territory, and which the capillaries are by no means capable of ; hence, in this condition they contract till the lumen is entirely closed (if the interruption is com- plete), and the parts are blanched. But with the blood flowing into them all the while, as in the normal condition, there is no difficulty in effecting expansion, while the high pressure in the arterial system in warm-blooded animals enables it to be made very energetic, and which the exigencies in the functions call for, in order to make it commensurate with the force expended in them. This necessity for producing afflux of the fluids in the organs simultaneous with expan- sion, has forcible illustration in the lungs, for with the force in the chest- walls, diaphragm, and muscles in the abdomen, in- clusive of the action in the lungs themselves, it would be utterly impossible to effect expansion in the absence of the air ; which one may readily prove upon himself by closing the nose and mouth and then attempting to inspire. He cannot expand his lungs, putting his force upon it and bringing everything to bear. But how easily it is done with removal of the obstruction, the air flowing into the organs pari passu with expansion for filling the room this effects in the alveoli, pressing against the walls, and in this manner aid- ing expansion. So, likewise, in the capillaries we have the 17J .MULTIPLE DICRoTlSM. blood flowing into them pari passu with expansion for occu- pying the room thus made, pressing against the walls, thereby aiding expansion, the principle being the same precisely as ob- tains in the lungs. Multiple Di erotism. — This brings us to the remaining diffi- culty in the tissue tracings, notably muliiple dicrotism. As we have seen, the systemic pumping-action in the lungs is let down in stages to the tissue territory, wrhich should give us but one dicrotic wave for all the vessels, inclusive of the heart ; whereas, in the capillary tracings we have sometimes two, and occasionally as many as three or even four present (Fig. 03), and which is undoubtedly due to interference on the part of the local functions and the action in the cells. And when so many dicrotic waves appear, we knowT there is something wrong in the tissues, or the cells are not duly supplied, and the circumstance is announced in this manner. In the case before us, in which the capillaries are choked with venous blood, therefore cannot act, dicrotism disappears ; wThile in the opposite condition of anaemia, produced by an application of ice to the inner side of the arm, or along the course of the brachial artery, for effecting contraction in the vessel, there- by to diminish the flow of blood in the tissues below the nor- mal amount, accentuates dicrotism (Fig. 50),* at once showing that its origin is in the capillary vessels, and due to the dimin- ished supplies in the cell-brood. In other words, the cell- brood is suffering, and this is the only means for increasing circulation. The action on the artery irons out the respiratory wave, but it does not stop dicrotism, for that is the voice of the cell-brood, the vox populi, that will not down. Explain the phenomena in the tissue tracings by the action in the heart ! No, Monsieur! You might as well have attempted to explain the force in this vast republic by the powers of the Chief Magistrate, who is only a servant of the people, and in which every individual is an independent integer, performing work so as to sustain himself, if it be not further than to eat and sleep, to rise up and lie down again, and attend to the calls of nature — all the same, they are his own acts and essen- *Ib., Fig. 329, produced in the same manner as the preceding, while the fall in the line of tracings indicates the amount of shrinkage in the hand. AE NESTING THE EESPIRATORY WAVES. 173 crT p" 2. i § || P crq 5- c rs & p. V! b " S p >3m B * CD the heart and vense cavse by reason of the damming of the blood in the right side during expiration, as has already Fig. 62. — Abdominal Sound. been demonstrated. I had no means of ascertaining it in millimeters, but the intra-abdominal pressure is very con- siderable. Thus, when the sound was first introduced through an opening in the linea alba, immediately above the umbilicus,, 190 HIGH PRESSURE IN THE ABDOMEN. and the cork withdrawn from the stem so as to permit the water to escape, it spurted out with great force against the opposite wall some eight feet distant, and would have gone farther, striking it some feet from the ground. It rose and fell with inspiration and expiration, and had there been sufficient water in the instrument, would have issued per saltam with respiration, the same as arterial blood with the rhythms in the heart and arteries, showing the great press- ure in the abdomen and the inevitable effect it must have upon the venous system in the abdomen. I do not mean that the pressure is as great as in the arterial system, but that there is considerable pressure in the abdomen, which oscillates with respiration, but highest during inspiration. After the first jet, other smaller jets followed synchronous with inspiration, till at last the quantity of water was so reduced that it simply rose and fell in the instrument, shooting up the stem during inspiration, then falling back out of sight again during expiration into the bulb of the instrument, the delicate india-rubber bag allow- ing it to do so. And it thus continued to oscillate all the while, no matter where the bulb was shifted, up or down, in the pel- vis as well as elsewhere, but always greatest in the region of the diaphragm and stomach. Furthermore, the pressure is higher in 2, fat than in a lean dog, showing conclusively that there is greater difficulty in carrying on the portal circulation in the former condition, since the accumulation of fat in the viscera tends to embarrass respiration, thereby choking the portal vessels ; hence this circumstance. Fat animals are always windy, the gas frequently escaping by the anus from the press- ure in the abdomen The explanation of the mechanics is obvious enough. The gas acts as a lever under the force of the muscles in the abdomen, and in the walls of the intestines for overcoming inertia in the venous blood, in this manner lifting it up to the chest-cavity and lungs, inclusive, of course, of the liquid aliment with the portal blood, the whole forming a con- nected movement, and it must do so in the very nature of things. It is all very beautiful, while nothing could be more simple : air upon the one hand, muscular force upon the other, the blood with the nutritive and force-producing elements in the intestines sandwiched between them, with the nervous force HIGH PKESSUEE IN THE ABDOMEN. 191 in the medulla oblongata for operating the mechanics and co- ordinating it with respiration. Mlrdbile! The pressure in the abdomen would account for the eleva- tion of the diaphragm in the chest-excavation, as has already been shown (Fig. 27). It is higher after death by reason of the contraction in the lungs, forcing out a larger amount 01 residual air than during life, while the viscera in the abdomen are compelled into the excavation in order to equalize press- ure ; hence this circumstance. And it would also account for the tendency in the viscera to escape through the natural and artificial openings from wounds in the abdomen, and which is increased during in- spiration,* loops of intestine and portions of omentum fairly leaping through the openings the instant they are made, from the high pressure in the abdomen. It takes considerable force to cause the viscera to burst through the openings in this manner. Last, but not least, when the diaphragm is rup- tured or incised (as has occasionally occurred), the viscera rush through the opening into the pleura and, compressing the lungs, extinguish life. In conclusion: That there is high pressure within the intestinal cavity itself also admits of easy demonstration by simply puncturing the gut, when the gases escape with audible noise, the walls at the same time col- lapsing, showing conclusively that they had been distended by the gases. Moreover, it would explain the rotund appear- ance, not to be accounted for by any other hypothesis, the walls being thus ballooned by the air. We are now prepared to take up the mechanics in the in- testinal canal. As we live by breathing and eating, the first thing to note is the adjustment that obtains between eating and breathing, an important adjustment obtaining in this respect. Thus, when the animal desires to take food (solids or liquids, it matters not), it rises to its feet (man to the sitting posture) in order to do so. Second, that during deglutition., respiration is suspended. The explanation of the phenomena is sufficiently easy. * A very notable example in the experience of obstetricians is the gush of blood which precedes the outcry of the parturient woman, and which is pro- duced by inspiration. 192 SUSPENSION OF ELSPIUAIION IN DEGLUTITION. It rises up in order to reduce pressure and facilitate expan- sion in the abdomen, which are essential for introducing the food into the cavity, doing so instinctively, but first com- pelled to it. At the same time, gravitation is also brought to bear for facilitating expansion, acting also upon the food ; whereas in the recumbent posture it acts adversely by increas- ing pressure in the abdomen, from the weight in the body com- pressing the abdomen against the ground, thereby inhibiting expansion ; a circumstance which is also easily demonstrated by lying upon the abdomen, then making an attempt to swallow liquid or solid food. It cannot be done but to the most limited extent ; and if the abdomen be at all pendulous, it will be utterly impossible to get down any whatever. This, then, is the explanation for the rising up to eat and drink. 2d. The suspension of respiration has its explanation in the circumstance that the diaphragm must be relaxed (expanded) in order to reduce pressure in the abdomen and relieve the muscular constriction around the oesophageal opening in the diaphragm, which constricts the tube during inspiration. Hence, there must be no inspiratiory effort during deglutition. It is the common impression, however, that ''suspension of respiration during deglutition is designed to obviate intrusion of the food into the air-passages ;' ' but while this important end is also attained, it is not the controlling principle in the mechanics, as is fully proven by the fact of its continuance after the food has passed the glottis and when all danger from intrusion is over, not pausing till the bolus has traversed the entire distance in the gullet and been safely lodged within the stomachal cavity. And the glottis, being at the very com- mencement of the gullet, is quickly passed, from the energetic action of the muscles of the pharynx, which are of the striated variety for compelling rapid action, the evident purpose being to rush it by the glottis, while it is the distance, together with the slower movements in the gullet, that consumes the time. Nor is the temporary arrest of the bolus in the gullet from mechanical causes, with resumption of respiration before the act is completed, an infraction of this important principle, since for the final consummation it still requires the suspension of respiration, and as though there had been no stoppage THE ACTION IN DEGLUTITION. 193 whatever, in order to relax the oesophageal opening, or pillars, in the diaphragm, at the same time reducing intra-abdominal pressure, the whole diaphragm, together with the muscles in the abdomen, expanding, which is accomplished by means of the reflex actions set up through the pneumogastric nerves from sensory impressions in the mucous surface. Thus, deglutition is seen to be far-reaching, a movement, in short, extending from centre to circumference of the body, and involving the most extensive adjustments for effecting it, while the mechanical principle underlying it is the one of pressure, and the power of producing rapid rhythmical changes in pressure. In the quadruped, when drinking from the ground, the liquid has to ascend the tube ; hence, it involves a greater expenditure of force on the part of the gullet than in man, who lifts it to his lips, thereby gains the force in gravitation. But the juggler, drinking while standing upon his head, re- verts to the old mechanics, and while he is able to accomplish the feat, he, at the same time, finds it much more difficult than the natural way, or by lifting it to his lips with a cup, with the body in an upright position, or with the head up. But it is quite as easy to effect expansion in the stomach and abdomen as in the normal position. The popular interest it excites is amusing. The idiots ! The act of deglutition, however, is somewhat complex. Briefly, when the food has been duly in- salivated and all is ready, the mouth-cavity contracts upon its contents, the tongue being forced up against the hard palate from before backward by the action of the hyo-glossal, stylo- glossal, and palato-glossal muscles, strongly arching the organ upon itself so as to throw the convex surface against the sur- face of the hard palate, and pulling it from before backward ; at the same time, the larynx is firmly approximated against the base of the tongue by the action of the genio-hyoidei, thyro-hyoidei, mylo-hyoidei, and the anterior bellies of the digastric muscles, the effect being to close the glottis and effectually prevent intrusion of the food into the air-passages, the base of the tongue also arching over it. At the same time this is going on, however, changes are taking place in the back of the mouth and pharynx for accelerating the passage of the bolus, notably as the root of the tongue approaches the velum 194 THE ACTION IN DEGLUTIT ON. palati and fauces — previously tightly closed ; these expand, the velum being drawn upward and backward, and op- posed to the posterior wall of the pharynx by means of the pharyngo-palati, and the levator and circumflexus pal- ati for obviating intrusion in the nasal passages, and with the pharynx at the same time widely expanding for sucking the food. The elevation of the larynx must have this effect, not to mention the special action in the mus- cles ; the bolus readily passes into the excavation, which closes at once upon it ; thence, by a series of rhythmical ex- pansions and contractions, is compelled through the tube to the stomach. And the pharyngeal muscles being striated, this secures energetic action in the pharynx for rushing it out of the dangerous locality, as before remarked. Otherwise, this differentiation of the muscles in the gullet is inexplicable. As soon as the food reaches the pharynx, the rellex actions are at once set up, nor pause till the bolus has reached the stomach. The sensory fibres, which lead to the rellex move- ments in the gullet, are contained in the palative branches of the fifth, and in the pharyngeal branch of the pneumogastrics, and the centre for their movements is in the olivary bodies in the medulla oblongata (Schroder v. d. Kolk). That the pro- gressive contractions and expansions which occur in the oesophagus during deglutition do not depend upon the stimu- lation of the advancing bolus, but are the result of a central coordination, is evident from the fact that the wave travels over ligatures or even excised portions of the oesophagus (Mosso). One other thing in this connection : When the mouth is closed it has a negative pressure corresponding to 2 to 4 milli- meters of mercury (Mezzer). In this manner, then, atmos- pheric pressure would serve for supporting the maxilla and tongue, while for increasing it, for producing the suction-action in the cavity during nursing and drinking, the lips close around the mamma or open in the fluid ; at the same time, the cavity is expanded by expanding the buccinator muscles and depress- ing the tongue, the fluids flowing in till expansion ceases, when the cavity contracts firmly upon it for compelling it into the pharynx, etc., etc. First and foremost, however, we must keep conspicuously in the foreground the principle of co- STOMACH AND WALLS OF THE ABDOMEN COOEDINATED. 195 ordination as it relates to the internal and external parts, together with the nervons combinations in the mednlla oblongata for compelling simultaneous action in them, since this is essential to the mechanics and the performance of the functions in the abdomen. As before remarked (p. 60, Fig. 16, 2, 3), the waves of ex- pansion in deglutition are not lost, but are added up in the general expansion which takes places in the stomach and the cavity of the abdomen, all the parts expanding pari passu with the ingestion of food ; otherwise, it were utterly impos- sible to introduce the food, since the progressive increase in pressure this should occasion in the stomach and abdomen would inevitably produce regurgitation. The extension of the pneumogastric trunks to the stomach, which they literally envelop with nervous filaments, and the correlation of these nerves with the nerves to the muscles in the abdomen, nota- bly the intercostals and phrenic nerves, has its explanation in this circumstance ; for in no other way could correspondence be produced for maintaining a balance in pressure in the stom- ach and abdomen, since the stomach is separated from the walls by the differentiation of a peritoneal cavity. Furthermore, that the abdomen does actually expand pari passu with ingestion is matter of easy demonstration by taking the dimensions before and after a meal, when it may be at once seen that expausion is in correspondence with the amount of ingesta. That ends the matter there. ISTow, then, it will scarcely be contended that deglutition — that is, the action in the gullet — can force open the stomach in order to produce the increase in the size of the organ when thus dis- tended with food, the powerful muscles in the abdomen in- hibiting this circumstance, not to mention the strain it would involve to the stomach. It sends a spasm through the chest. Gott in Himmel ! Give it the go-by instantly ; it would choke the life out of you. And do not think of forcing open the stomach and abdomen by any means whatever, but rather permit them to expand of their own option under the stimulus of the food and the reflex actions this excites in the medulla oblongata from the sensory impressions it produces in the mucous surface, or the same as obtains in the lower animals. 196 PHYSIOLOGICAL ANATOMY. You cannot improve the mechanics, founded as it is in the organic laws, therefore wonderfully perfect and harmonious in all the movements. In short, the effort to explain this beautiful mechanism in the absence of the fundamental principle underlying it, is as futile as the attempt to sit upon nothing. Food requires room to be made for it, and you must permit the stomach and abdomen to expand pari passu with the ingoing of the ingesta in order to make this room ; otherwise, the food could never be introduced and animal life would be impossible. All is Tig. 63.— A Longitudinal Section of the Human Stomach, showing the folds in the mucous membrane. — Gray. chaos in the absence of this law and what it involves. It is needless to extend the matter. Concerning the Action in the Stomach. — Coming to the stom- ach, the first thing to engage attention is the anatomical dis- positions in the mucous membrane, which contains the organs of secretion and absorption. In the empty or con- tracted condition of the stomach, the mucuous membrane is thrown into a series of longitudinal folds (Fig. 63), the loose areolar tissue connecting it with the adjacent circular mus- PHYSIOLOGICAL ANATOMY. 197 ■cles, which form a continuous cylinder through the whole length of the intestinal canal, admitting of this action in the mucous membrane, or, rather, compelling it, since it does not possess the same powers in expansion and contraction as the muscles ; hence, when the organ becomes greatly contracted, as in the empty condition, this folding in the mucous lining occurs, while in the expanded condition, produced by inges- Fig. 64. — A Transverse Section through the Fundasof the Stomach in a Child. — Verson. a, a, cylindrical epithelium ; b, b, peptic tubes ; c, muscalaris mucosas ; d, sub- mucous tissue ; e, circular muscular layer ; g, peritoneum ; h, ganglia of Auerbach. tion, they again apply themselves accurately to the muscles, causing the gland-tubes to stand erect and facilitating circula- tion and secretion correspondingly. The following beautiful cut, by a distinguished German microscopist, will serve for impressing the matter (Fig. 64). The great relative thickness of the circular muscles (e) is a conspicuous circumstance, 198 PHYSIOLOGICAL ANATOMY. while the loose areolar tissue is drawn into forcible extension by the folds in the mucous membrane. Of course, the secre- tions for dissolving the food should be compelled out of the tubes as fast as they are formed ; and looking to the secretory processes in these organs, then, it is readily perceived how this is materially assisted by the action in the circular muscles for compelling the contents in the cavity ; at the same time, addi- tional force is put upon it by means of the finer adjustments that obtain in the muscalaris mucosa. Briefly, they are as follows : The peptic and mucous glands occupy a perpendicular position in the mucosa, the closed end resting against the circular muscles, with the loose con- nective tissue and muscalaris mucosae between, in intimate relation with them, the open end at the free surface. The result of this arrangement is that, when the stomach contracts upon its contents (inclusive of the air it contains for in- creasing the action) it compresses them firmly against the mucous surface, tending to flatten this more and more, and so compelling the secretions into the stomachal cavity, constring- ing the glands and milking them, as it were, into the food to be dissolved. And being sandwiched, so to speak, between the muscles and the food, the open ends communicating with the latter, this action in the muscles could not otherwise than have that effect upon the glands. It must do so in the very nature of things. The movements which set in in the stomach as soon as food is introduced for disintegrating the boluses, would have the effect, then, of milking the secretions, the object being to bring the food into rapid contact with the solvents. But this, in turn, is supplemented by the force in the muscalaris mucosa for increasing the action in the tubes. Thus numerous small fasciculi proceeding from the muscalaris mucosa, extend some distance up the tubes, crossing and interlacing around them, and so forming, as it were, a minute muscular envelope to this portion of the follicles for expressing the contents into the stomachal cavity. Hence, the most com- prehensive arrangements obtain in the stomach for compelling the secretions into the food. Finally, since the gland cells are contained in the thinnest of membranes (membrana proprii) (Figs. 65, 66), it will at PHYSIOLOGICAL ANATOMY. 199 once be seen that mechanical force is necessary for effecting rapid expulsion of the secretions. Concerning the Capillary Network in the Stomach. — In Fig. 65.— Vertical Section of the Human Gastric Mucous Membrane, a, ridges ; 6, peptic glands. — Frey. Fig. 66.— Peptic Glands from the Human Stomach after Treatment with Alkalies. — Frey. order to maintain secretion in correspondence with the amount of ingesta it calls for appropriate arrangements in the capillary network to the gastric glands, for increasing the blood supply, 200 PHYSIOLOGICAL ANATOMY. which ebbs and flows with digestion, and in correspondence with this being increased the moment that food is introduced, diminishing as it passes out of the cavity, and lowest during the interim. The vascular turgescence which the stimulus of the food pro- duces in the gastric mucous membrane (previously pale) has forcible illustration in injected preparations (Fig. 07, A B) ; but in order to fully understand the mechanics, it will be necessary to go a little deeper in the tissues passing through and through the membrane, for the purpose of getting at the network between the tubes as well, as also to obtain a view of the relations which they sustain to the arterial and venous systems, or the afferent and efferent vessels to the mucous membrane, which is given us in the following beautiful cut (Fig. Gs) by that accomplished German histologist at Zurich, from whom we have borrowed so copiously. For example, it will be seen that the arterial feeder (A), in passing up between the tubes to reach the mucous surface, breaks up into a capil- lary network for feeding the gland cells in the tubes, continu- ing thence to the mucous surface, where each tubular orifice is surrounded by a vascular collar, while out of this telangiectatic plexus a great efferent vessel (d) carries the blood into the portal vein. This bird's-eye view will give some idea of the vascular arrangements over the entire surface of the gastric mucous membrane. Now, then, we can readily understand how stimulation of the mucous surface by springing open the arterial feeder under the action of the special nervous ganglia should at once produce a rush of blood into the plexuses ; the high pressure in the arterial system compelling this to be done the instant that expansion sets in, and which, of course, should increase the action in the gland cells correspondingly for maintaining ' this in due proportion with the quantity of ingesta. But the circumstance to which attention is directed more especially is the great relative size of the efferent vessel to the plexuses (d), and which is certainly needing explanation, since the amount of depletion to which the long-meshed capillaries are necessarily subject for supplying the gland cells before reach- ing the round-meshed network upon the surface would natur- PHYSIOLOGICAL ANATOMY. 201 ally lead one to expect the very opposite of this, or a small rather than a large efferent vessel. Nevertheless, we have this great vessel springing out of this last network ; and since this can effect no action in the peptic glands — being at the free end of the tubes — it must have reference to other important functions, either absorption, or else to pour out gas in the intestine ; most probably both are included. It will thus be seen from the arrangements that obtain in the parts, that rapid absorption is made inevitable from the very nature of things, dialyzable with nou-dialyzable substances, otherwise inexplicable ; notably, the rapid absorption of alcohol, which should never enter the circulation at all, never- theless is rapidly absorbed ;* since the high pressure, which Fig. 67.— Appearance of the Lining Membrane of the Stomach, in an Injected Prepara- tion. A, from the convex surface of the rugae ; B, from the neighborhood of the pylorus, where the orifices of the gastric follicles occupy the interspaces of the deepest portions of the vascular network. — Carpenter. is produced in the stomach by means of the firm con- traction in the circular muscles must inevitably have this effect upon the liquid contents, compelling them through the membranes. Furthermore, the necessity for such short and expeditious journey of the fluids to the blood, is made sufficiently obvious in the case of water, for the enormous demands in the nutritive processes and for main- taining a balance in body-temperature, which is accomplished * "The rapidity with which alcohol is absorbed in the stomach is forcibly shown by the experiments of Dr. Percy, who found that when strong alcohol was injected into the stomach of dogs, the animals would sometimes fall in- sensible to the ground immediately upon the completion of the injection, their respiratory and cardiac movements ceasing within two minutes ; and that on post-mortem examination in such cases, the stomach was nearly empty, while the blood was highly charged with alcohol." "Experimental Inquiry Concerning the Presence of Alcohol in the Ventricles of the Brain," p. 61. 202 PHYSIOLOGICAL ANATOMY. by surface evaporation, would soon make it impossible to carry on circulation ; hence, this open door for rapidly filling the vessels and the eagerness with which thirst is quenched. So, then, this circumstance, in the special anatomy of the organ, is strictly in accord with the physiological requirements, the results of daily experience and physiological experiment. Of course, absorption is in correspondence with the stimulus to action, and alcohol being a powerful stimulant, producing rapid expansion in the vessels, with energetic action in the Fig. 68.— Vascular Network of the Human Gastric Mucous Membrane — half diagram- matic.— Frey. A, fiue arterial twig, which breaks up into a long-meshed capillary network (b), which passes again into a round-meshed one (c) around the openings of the glands. From this latter the vein (the large dark vessel) takes its origin. muscular walls, which contract firmly upon it, the most favorable conditions would obtain for compelling rapid absorp- tion, the great tenuity of the liquid also favoring it. Indeed, every one knows the liquids are rapidly absorbed in the stomach, while the mechanics is sufficiently obvious, the force in the muscular walls being available for this purpose. Finally, another important fact remains for mention, notably the air secreted in the cavity, passing out through the surface capillaries ; a quantity of air being also ingested with the food, and which assists in distending or ballooning the organ, SECRETION of gases in the stomach. 203 smoothing out the folds in the mucous membrane, and making the force in the walls available in the work of digestion and absorption ; at the same time acting mechanically for effecting rapid disintegration of the boluses. The oxygen carried in with the atmosphere passes into the blood through the plexuses — a remnant of the old or primitive method of respi- ration ; while carbonic acid passes out of the blood into the stomach in large quantities, for increasing pressure in the organ, the force in the arterial system at the same time aiding it. And not carbonic acid only, but nitrogen as well, the two gases being thus poured into the stomach and the other portions of the intestinal canal from the surface capillaries during digestion, the mechanics being fundamentally the same throughout, and which is regulated by nervous force so as to maintain a given amount of pressure in the canal and the cavity of the abdomen. Moreover, it would explain the fol- lowing well-known facts, otherwise inexplicable ; notably: 1st. The function possessed by the intestines of rapidly secreting air, which is proven to demonstration by drawing out a loop of intestine, isolating it by ligature, freeing it of its contents, and returning it again to the abdomen, the collapsed "walls soon becoming distended, as previously. 2d. It would account for the disappearance of carbonic acid and nitrogen in respired air. For example : the carbonic acid expired does not represent the chemical equivalent of the oxygen inspired ; also, that an amount of nitrogen disappears ; while both are contained in arterial blood and are present in large quantities in the intestines, especially during digestion, which they serve to expedite by their mechanical action, and increase the absorptive processes correspondingly, as before re- marked. Finally, it would explain the rapid evolution of gas in the intestines produced by a vegetable diet, which is harder to digest than one of meats ; also, why the condition of colic can be induced by substances that resist digestion, and which stimulate an over-production of the gases, leading to distension and pain. And that this is not due to fermentative processes, is proven by the fact that the gases, when liberated — as I have done by means of a trocar and canula in the horse — are perfectly 204 IMPORT OF THE MOVEMENTS IN DIGESTION. free from any odor of putrefaction or fermentation ; in fact, nearly odorless. Also, the rapid evolution of the gases in dyspepsia, hys- teria, etc., in "which they are poured out with extraordinary rapidity, producing enormous distensions of the abdomen in the shortest space of time. Furthermore, the power to secrete air to subserve other uses than those immediately connected with the digestive and absorptive processes is seen in the air-bladders of fishes, by means of which they buoy themselves in the media, raising and lowering the body readily to any depth by simply expand- ing the air-sacs and body-walls, thereby diminishing or increas- ing body-density, according to whether they desire to ascend or descend, as the case may be ; at the same time, they expedite it by the action in the fins and tail. Another application of the principle is seen in the eggs of birds, etc., in the formation of an air-charnber (Fig. 141), by means of which the rhythmi- cal changes in pressure can be made within the egg. in connec- tion with the actions in the heart, etc , otherwise impossible. Finally, we have this latest application in the intestines for expediting the digestive and absorptive processes in the mam- malia, of which we have been speaking. Concerning the Movements in, the Stomach. — According to Beaumont, soon after digestion sets in the stomach becomes divided by a circular constriction into two distinct compart- ments, in which the action differs; the rhythmical contractions and expansions in the cardiac end being slow and gentle, while in the pyloric they are more rapid and energetic. This division in the organ is produced by a firm contraction of transverse muscular fibres near the pyloric end, the smaller compartment occupying about one-third and the large about two-thirds of the organ ; while between the two ends a con- stant current of the fluids is maintained, by means of which the boluses are soon disintegrated and penetrated in every portion with the gastric juices. "As the alimentary bolus enters the stomach by the cardiac opening, it turns to the left, descends into the great pouch, and follows the great curvature to the pyloric end. It then returns to the cardiac orifice by the lesser curvature, and takes again the same course as before. IMPOKT OF THE MOVEMENTS IN DIGESTION. 205 While these revolutions, so to speak, of the alimentary mass are going on, the food is turned over and over, so that it be- comes intimately mixed with the digestive fluids and subjected to a certain amount of trituration." " When the thermometer bulb arrived at the contracted septum, which was three or four inches from the pyloric end, it was at first stopped by the forci- ble contraction ; but in a short time there was a gentle relaxa- tion, which allowed it to pass, when it was drawn quite forcibly for three or four inches toward the pyloric opening When in this portion of the stomach, the bulb was firmly grasped and made to undergo a spiral motion ; and if drawn forcibly out, it gave to the fingers the sensation of being held by a strong suction force. As soon as relaxation occurs, the bulb is passed back to the seat of stricture, and, when pulled through this, it moves freely in the great cavity Each of these revolutions occupied from one to three minutes. They were slower at first than after digestion had been somewhat advanced. ' ' These graphic excerpts of practical observations made upon the stomach during digestion would leave no doubt, then, of the mechanical principle which applies for increasing diges- tion and absorption, namely, rapid rhythm'' cal changes in pressure, the alternating contractions and expansions in the two ends serving to maintain a current of the viscid chyme through the limits in the organ, but all the while flowing from, high to low pressure, in conformity with organic law. When contraction sets in, however, the sudden reversal of the cur- rent which this effects produces the spiral motion — a minia- ture whirlpool, as it were — while the suction-force spoken of was simply a pulling-force produced by the current setting into the compartment and the energy of the contraction twist- ing the current upon itself, and, of course, pulling the bulb along with it. As soon as expansion is effected, however, this restores the horizontal line again, when the current, deflected by the opposite wall, simply carries the bulb back to the seat of constriction. It is all simple enough. When the bolus enters the stomach, it, of course, falls into the surface current which sets into the great cul de sac, the force in the muscular contractions in the pyloric end, by reason: 206 MTTSCl LAK FORCE IN DIGESTION. of greater energy, producing this surface current ; while "the food is turned over and over" by reason of the deeper cur- rent setting in the opposite direction along the floor of the organ into which the boluses project, and, of course, causing them to turn over and over. Furthermore, it is also easily perceived, from the nature of the mechanical adjustments that obtain in the gastric glands and capillaries, that secretion and absorption are maintained in correspondence with the c/iurn- ing-actlon, in the stomach. I do not see necessity for adding another word, the matter being so obvious. Something might Fig. 69. — External Muscular Fibres in the Stomach. — Gray. be said, however, in regard to the muscles in the walls of the stomach, which is the real force in digestion and absorption ; as it is through them the rhythmical changes in pressure are produced. They are nearly all circular muscles (Figs. 69, 70) ; with these exceptions, however, that upon the external surface scattering longitudinal fibres extend along the sides, and greater and lesser curvatures (thicker in these two localities), with a thick fan-shaped layer spread out over the upper portions of the great cul de sac formed by the longitu- dinal muscles in the oesophagus (Fig. 69) ; while upon the MUSCULAR FOKCE IN DIGESTION. 207 internal surface we have a wide, thin layer of longitudinal muscles, embracing the great cul de sac and extending some distance toward the pyloric end, but fading out. however, and disappearing upon the sides of the organ (Fig. 70). The firm constriction near the pyloric end is, of course, produced by the contraction of a band of circular muscles, as are also the rhythmical contractions and expansions in the two ends, while i he longitudinal fibres in the great cul de sac should greatly expedite the pumping action by compelling the contents toward the pyloric end during their contraction, since it must !l Pig. 70. — Fibres seen with the Stomach hvcr^M. — oappey. 1, LKsophagus ; 2, circular fibres at the oesophageal opening : 3, 3. circular fibres at the lesser curvature : 4, 4, circular fibres at the pylorus ; 5, 5, 6, 7. 8. oblique fibres : 9, 10, fibres of this layer covering the greater pouch ; 11, portion of the stomach from which these fibres have been removed to show the subjacent circular fibres. inevitably effect a corresponding shortening in the longi- tudinal axis of the organ. One result of the circular con- striction would be to shorten the longitudinal fibres embracing the cul de sac (Pig. ?> , 5, 6, 7, h) ; at the same time, by giving them a firm point to contract upon, would make their action upon the cul de sac still more effective for compelling the contents toward the pyloric end, while the greater number of the circular muscles in this end, together with the diminished area, should increase the energy in the rhythmical expansions and contractions correspondingly, increasing the frequency and 208 ACTION IN THE SMALL INTESTINES. force of the pumping actions in this end for compelling move- ment in the contents. In this manner, then, muscular force is so distributed as to make it effective upon every portion of the gastric contents for compelling rapid digestion and absorption, the energy of whicli is, of course, regulated by nervous force, while this in turn is determined by the requirements in the organism. Furthermore, we can also readily understand how the mechan- ical action in the air-cushion should increase the churning? action correspondingly, since the immediate result is a great gain in srjace in which to effect it ; at the same time the air serves for disintegrating the boluses by transmitting the force in the muscular waits upon them. In fine, the air is a great and essential factor in the mechanics in the abdomen. Concerning the Action in the Small Intestines. — The mu- cous membrane of the small intestines is more complicated than that of the stomach ; but we shall pass over the more prominent features as rapidly as we can, for the purpose of showing the principle in the mechanics and the great role which is performed by the muscular cylinder. Beginning with the duodenum, we have the mucous membrane arranged in crescentic folds [valvulo3 conniventes] (Fig. SG), which continue throughout the jejunum and into the ileum to about the middle portions, where they fade out and disappear. They extend about one-half to three-fourths around the cylinder, springing from every portion of the circumference, the evident object being for increasing the secretory and absorptive processes, at the same time providing for free action in the muscles or peristalsis ; but in contraction they are made more prominent. Through the rest of the ileum it is smooth, and in the large intestine is evenly applied over the surface of the sacculi ; while in the rectum it is again thrown into longitudinal folds, as in the oesophagus and stomach, as the necessary provision for effecting the wide expansions which occur in this pouch, which functions as a receptacle for the faeces before final ex- pulsion. The three valvular folds corresponding with the upper, middle and vesicle portions tend to delay the onward movement, as in the sacculi of the colon, at the same time increasing the absorptive surface ; while the arrangement that PHYSIOLOGICAL ANATOMY. 209 obtains at the ileocsecal valve serves for obviating reflux in the small intestines. The following diagram will give some idea of the arrange- ment of the glandular structures in the duodenum (Fig. 7 J). In the so-called Brunnef s glands (c) found in the duodenum only — in the upper portions especially — we have a group of open gland vesicles of microscopic dimensions, flask-shaped, with short necks, that discharge their contents through an axial canal ; and are simply transitional forms of the simple gland tubes that have coalesced near the blind ends, forming a new anatomical unit, or a so-called racemose gland (Frey). In the compound peptic glands the same circumstance is seen, only that coalescence occurs higher up the tubes and nearer Fig. 71.— Vertical Section of Mucous Membrane of Duodenum, shoTring Brunner's glands, a, Follicles of Lieberkiilin ; b, cellular coat of intestine ; c, Brunner's glands ; d, annular fibres of muscular coat ; e, longitudinal fibres of muscular coat. — Wilson. the mucous surface, is also limited to several tubes only ; here a whole group coalesce. They secrete a clear alkaline mucus, free of form elements. Arranged around the central canal as foot-stalk, they bear striking resemblance to a bunch of grapes (Fig. 72). The relations they sustain to the bases of the villi is shown in the following cut (Fig. 73). The simpler forms, however, are seen in the crypts or follicles of LieberJcuJin (Fig. 71, a), arranged perpendicularly to the surface, upon which they open by circular apertures, and occupy the whole free surface of the small and large intestines, opening around the bases of the villi and the solitary glands. Their walls, however, are exceedingly thin, at times nearlv indistinguishable from the surrounding tissues 2J0 PHYSIOLOGICAL ANATOMY. (Fig. 74). The contents of these crypts, unlike those of Bru aner" s glands, consist of delicate, columnar, nucleated cells (a), with the bases resting against the membrana propria, Fig 72. — One of Brumwr'.-: Racemose '. Hands, from the Human Being. — Prey. Fig. 73. — Brunner'ls Glands, from the Duodenum. — Frey. a, Villi ; b, bodies of glands ; c, excretory canal opening between the villi. the apices presenting in the crypt (Fig. 74, K ; Fig. 75, d). These, together with the axial canal, may be seen in every trans- verse section (Fig. 75, d). According to Schulze, between these PHYSIOLOGICAL ANATOMY. 211 cells other goblet cells may present themselves (Fig. 76, a). They were thought to be confined to the surface of the villi. While the orifices of the Lieberkiihnian follicles are neces- Fig. 74.— Follicle of Lieberkuhn, greatly magnified. — Verson. K, follicle ; a, a, epithe- lium ; d, adenoid tissue, from which the cells have been removed by penciling ; T, fibrous tissue on the opposite side. Fig. 75.— From the Small Intestine of the Rabbit; a, Tissue of the mucous membrane ; 6, lymphatic canal ; c, an empty transverse section of a gland of Lieberkuhn ; d, another of the same occupied by cells. — Frey . 212 PHYSIOLOGICAL ANA I OMY. sarily separated by the villi, the tubes dilate beneath them in such manner as almost to bring them in contact, leaving only small interspaces for the passage of vessels and muscular fasciculi. Finally, we have to mention the lymphoid follicles or glandules solitaries, that are scattered over the mucous membrane of the small intestine, and when a gminated forming Peyer's patches, and which are analogous to lymphatic glands. They are situated either in the tissue of the mucous membrane, or, when of considerable length, project down into the submucosa, as occurs in Peyer's patches, in which the bases of the follicles are approximated to the circular mus- cles, while the apices project upon the mucous surface sur- rounded by villi, the fibres of the muscalaris mucoscs being separated and pushed aside by the enlarged follicles (Pig. 77, m, S, K). They are ductless glands, and the means for Fig. 76. — Epithelial Cells from a Human Intestinal Villus (after Schulze). a, Goblet cells ; b, ordinary elements. increasing circulation in them and for compelling out the secre- tions possesses special interest. They occur opposite to the attachment of the mesentery, consequently their caps are kept constantly submerged in the intestinal fluids, gravitation compelling this circumstance ; are from one to three inches in length and about an inch in breadth, are covered with villi, and the Lieberkiihnian fol- licles form a circle around them ; are more numerous in the lower portions of the ileum, while they vary from twenty to thirty, and even more, in number, becoming less and less, however, as age advances. The usual number of follicles in a patch is from twenty to thirty, but they vary from as low as three to seven, while the large patches may contain from fifty to sixty (Prey). The following illustration will show the character of the mucous membrane in the large intestine, and the relations it sustains to the circular muscles (Fig. 7). PHYSIOLOGICAL ANATOMY. 213 The crypts of Lieberkulm continue, but the villi extend no further than the free border of the ileo-csecal valve. It pre- sents the same structure and arrangement of its constituent parts as the small intestine, of which it is a direct continua- tion. Now, then, the point to which attention is specially directed concerns the action in the muscular cylinder in which the mucous membrane is placed. From the nature of these z Fig. 77.— A Longitudinal Section of the Small Intestine of a Rabbit, through a Peyer's Patch (S).— Verson. Z, Z, villi ; J, follicles of Lieberkuhn ; K, cap of a gland ; m, muscalaris mucosae ; C, C, submucosa ; S, glands of Peyer ; B, circular muscles ; L, longitudinal muscles ; P, peritoneum. anatomical dispositions in the mucous membrane, and the me- chanical adjustments that obtain in the intestine, it follows that contraction in the muscles must have the effect of forcibly compressing the gland follicles and lymphoid follicles (Figs. 71-78), and compelling the secretions out of them, gently but effectually constringing them, and milking them, so to speak, 214 PHYSIOLOGICAL ANATOMY. of their contents by means of the uniform compression ex- erted through the elastic air-cushion under the energy in the muscles. Sandwiched as they are between these forces, with the mus- cles as the firm floor of support, the cushion pressing against them, it could not otherwise than have this effect upon the glands. It at once settles the matter. The air is in there and it cannot get away, and the muscles certainly contract; the rest follows as an inevitable sequence. Xow, then, to this must be added the tine adjustments in the muscularis mucosae, Fig. 78. — Section of the Large Intestine of a Rabbit. J, crypts of Lieberkiihn ; a, epithelium ; b, mucosa ; m, muscularis mucos.-e : s, submucosa ; R, circular muscular layer ; L, longitudinal muscular layer ; p, peritoneum. — Verson. and the thing will be complete. It must be borne in mind that the viscid secretions are difficult to move ; hence, force must be applied directly to the follicles, which is done by means of small muscular fasciculi extending from t lie muscularis mu- cosas between the acini of Brunners glands and between the follicles of Lieberkuhn ; but are much more numerous in the villi, running upward into the parenchyma, so as to form the wall of the central lacteal (Fig. 98, m, I). This, together with the force in the circular muscles, exerted in the manner as stated, compel Qe secretions out of the fol- PHYSIOLOGICAL ANATOMY. 215 licles. It now remains to take np the work of absorption, for which these adjustments are equally effective, bringing out, however, some fresh features in the mechanics which are extremely beautiful and charming to look upon. There is nothing more wonderful than animal mechanics. The following illustration will give some idea of the general appearance of the mucous membrane of the small intestines (Fig. 79). By means of the villosities, together with the cres- cendo folds in the membrane, the mucous surface is enor- mously increased ; but the former have more to do with the absorptive processes simply, though, by reason of the special Fig. 79. — Portion of the Mucous Membrane of Small Intestines, showing the villi and the apertures of the simple follicles, magnified 19 times. — Wilson. In the hollows between the villi are seen the apertures of simple f ollieles (b) ; and near the bottom of the figure is a zone of follicles (a) surrounding a solitary gland. capillary arrangements which obtain around the outlets to the follicles of Lieberkiihn (Fig. 80, d), or the same as obtains in the stomach (Fig. 68, c), absorption goes on quite actively, independently of the villi ; only that it is not so rapid as in the stomach, for the vascular network is not so extensive, the greater portion of the capillaries going into the villi And it will be seen that here also there is a great contrast in the size of the arterial feeders and the discharging vessels or veins (a, c), the veins being out of proportion to the arterial feeders, the import of which has already been stated. Now, then, between these vascular loops and the liquids to be ab- sorbed is the layer of columnar epithelium ; and the question 216 PHYSIOLOGICAL ANA'IOMY before us concerns the manner tins barrier is passed, or bow fat, albumen and other non-dialyzable substances effect a rapid passage into the interior of the cells, the membrane (membrana propria) beyond, and so get into the interior of the villi to the capillaries and central lacteal. Furthermore, keep the fact in mind that the fat is simply emulsified, not saponified, while albumen passes in freely unchanged, especially when given in large quantities, thereby showing conclusively the existence of a mechanical force for compelling them through the membranes ; otherwise is inexplicable. This mechanics is Fig. 80. — Vascular System of an Intestinal Villus in the Rabbit, a, The arteries (shaded), breaking up first into a capillary network around the glands of Lieberkuhn (d) ; b, network of capillaries in the villus ; c, venous vessels (unshaded). — Frey. also easily understood. Thus, the columnar epithelia are covered by a perforated lid of thickened epithelium (Fig. bl, a, b), which acts as a sieve or colander for strain- ing the chyle, while the muscular cylinder contracts for forcing it into the epithelia. whence it is passed in due time into the parenchyma of the villi, and compelled thence into the capillaries and the central lacteal, the coarser par- ticles passing by the vessels into the latter, which functions as a drainage system to the villi. The lids fit neatly over the surface of the cells, and being in close apposition and firmly consolidated by animal cement, which fills up the interstices PHYSIOLOGICAL ANATOMY. 217 (Fig 82, 5), present an appearance not unlike a mosaic pave- ment (81, b). But when macerated in water, they are easily loosened by pressure (Fig. <"■ 2, a) ; the splitting up of the lids through the perforations giving them the appearance of cilia, is a result of post-mortem changes in the cells. Thus con- stituted, then, the force in the muscular cylinder is readily brought to bear for compelling the liquid aliment into those myriads of little organs (each one of which may be regarded as a distinct gland in itself) that are spread out like a sheet over the external surface of the villi for effecting further metamorphosis upon the aliment, thence into the parenchyma of the villi, thence into the vessels, as before stated ; the structures in the villus — epithelium, blood-capillaries, and central lacteal embraced by its special muscles (Fig. 98, Z, m\ all acting to- gether and in harmonious concert with the force in the muscu- Fig. 81. — Columnar Cells from the Small Intestine of the Rabbit, a, Side view of cells with thickened raised lids traversed by pores ; 6, view from above, in which the orifices of the pores appear like dots. — Frey. lar cylinder for compelling rapid absorption. This additional force in the fine adjustment spoken of in the muscularis mucosae must necessarily increase the action, since the rhythmical contractions and expansions in the muscular fasciculi that penetrate the parenchyma and form the wall of the central lacteal, could not otherwise than have that effect, must do so, in the very nature of things, acting as a little suction-pump and increasing circulation in the vessels correspondingly. And with high intra-intestinal pressure produced by the muscular cylinder and the gases in the intestines, together with this pumping action in the villi, absorption should go on very rapidly, as a matter of course ; while the rhythmical expansions and contractions taking place in the gut itself, diffusing the aliment over the mucous sur- face, at the same time increasing pressure should increase the action correspondingly. And through these combined actions in the organ effected by means of nervous force, we can very 218 RAFID ABSORPTION INEVITABLE. readily understand the rapid absorption of non-dialyzable substances, otherwise inexplicable. Nay, bow even particles of finely-divided charcoal may present in the mesenteric veins (Oesterlen); and why similar results have been obtained by Eberhard, Mensonides, and by Donders, not only with char- coal, but also with sulphur, and even with starch, the latter substance being at once detectable in the blood by the iodine test. Furthermore, there can be no doubt but that they enter the circulation through the epithelial cells of the villi, as the presence of psorosperms in the interior of these has been distinctly seen (Klebs); while they are nearly double their size soon after digestion sets in, and of a milky appear- Eig. 82.— The same cells. At a, the border is loosened by water and slight pressure ; b, natural condition ; c. a portion of the lid destroyed ; d, e, /, the latter is resolved into a number of rod-like or prismatic pieces, by maceration in water. — Frey. ance from the quantity of fat they contain ; and that fat enters the blood-vessels also, as well as the central lacteals, is proven by the opalescent whiteness of the superficial capillary net- work, and the quantity of fat contained in the portal veins, fully one-half the fat being taken up by the veins.* And with all these muscles in the gut, the fine with the coarse adjustments that obtain, the nerves for operating them, together with the air-cushion as the lever for effecting the changes in pressure upon the contents, no reason on earth presents why absorption should not be very rapid. And the miserable device which comes to us as a suggestion by a promi- nent English microscopist, that the fat finds its way to the central lacteal by passing between these cells, cannot be entertained for a single moment even ; since this would pass it Zawilski, Ludwig's Arbeiten, 1876, p. 147. EAPID ABSORPTION INEVITABLE. 219 through the long line of cement binding these minnte organs together, and should undermine the very foundations of this beautiful structure ; while it would leave unexplained the rapid absorption of fat by the blood vessels, together with the entire anatomy in the gut as means to ends. What ! The chief force-producer burrowing under the foundations in order to get into the building ? Nein ! Niclit zu glauben I 2s ever under the canopy of heaven but by the public way through the open front-door — i. e., the sieve-like openings in the epithelium — with the force in the muscles, the fine and coarse adjustments for assisting the passage. The one explains everything ; the other explains nothing, which at once exposes it. Besides, we positively know the fat enters the cells very rapidly, so that they soon become twice the size in the empty condition, and the fat is easily detectable in the milky appearance it imparts to the cells. For increas- ing the action we have only to. increase pressure in the cavity by contracting the muscular walls of the gut, at the same time increasing the action in the villi, the whole per- forming as a single organ only for pumping the fluids into the vessels. Hence the slow and sustained contraction which fol- lows peristalsis. And with the anatomical dispositions which obtain in the organs and the mechanical principle which applies for increasing circulation, nu reason presents why digestion and absorption should not be made commensurate with the physiological requirements. This explains every- thing ; whereas the old method explains little or nothing — nay, is pitiful in its utter helplessness and power to help itself ; vainly groping in the tissues with the rnicroscoTje in search of the key to the vexed problem, not to be found with the microscope, but in the organic law itself underlying animal structure. And from this stand-point the whole mechanics in the animal circulation is at once made intelligible, from the cell itself to the cell-empire, the multitudinous arrangements in the structures falling readily into line in regular order and succession. But in the absence of this law of pressure and fluid equilibrium, which is being thus incessantly invoked in the measure of the physiological requirements, all are inex- plicable, all is chaos. CHAPTER X. KESPIRATION AND THE PORTAL CIRCULATION Circulation in the Liver Dependent upon Respiration — Mechanics in the Diaphragm and Walls of the Abdomen Respecting it — The Mesentery a Soft, Elastic Cushion for Effecting Gentle Compression of the Liver-Substance, under the Action in the Dia- phragm and Walls of the Abdomen during Inspiration for Increasing its Circulation — Mode of Demonstrating this Circumstance — Effect upon the Portal Vessels and Lower Cava-System — Absence of Valves in the Veins within the Abdomen, save in the Pelvic Viscera Only — Explanation for the Latter Circumstance — Physiological Anatomy of the Liver, with Reference to Circulation — Why the Hepatic Veins are Incorporated with the Liver-Substance — Relations of the Portal System to the Hepatic Viens — Why Rhythmical Compression of the Liver-Substance during Res- piration should Increase Circulation in the Inter- and Intra-Lobular Vessels Corre spondingly — Automatic Action in the Portal Vessels Synchronous with Respiration for further Increasing it — Mechanics for Circulating Bile — The Action in the Gall- Bladder an.l Bile-Ducts — The Action in the Duodenum, in Connection with the Biliary and Pancreatic Secretions — Adjustments in the Viscera Necessitated by the Action in the Diaphragm — Mechanics Connected with the Openings in the Dia- phragm— (Esophagus Constricted during Inspiration, while the Vena-Cava Lumen is thrown Widely Open ; as also the Aortic — Elongation and Contraction of CEsophagus with Inspiration and Expiration — Ditto Venae Cava? — Ditto Portal Vessels and Renal Veins — Similarity in the Anatomical Dispositions of the Muscles in these Organs. Before taking up the nervous apparatus to the intestines, it will be necessary to make a rapid survey of the glandular ap- pendages and the incidental adjustments rendered necessary by the action in the diaphragm ; since the nervous apparatus effects coordination, to the end that the whole should work together harmoniously, without let or hinderance, within cer- tain prescribed limits, that automatism may be maintained in the organs and structures, which is necessary to the existence of the organism. It is very comprehensive. But it is equally manifest that all of it is based upon pressure, and the power of producing rapid rhythmical changes in pressure for in- creasing circulation and compelling this to be in correspond- ence with the physiological requirements, which, of course, would include the secretions in the glands, with the arrange- THE ABDOMEN A VENTRICLE. 221 ments for compelling them into the cavity of the intestine. For example, we can readily understand why the liver- substance is spread out, so to speak, upon the incurvated surface of the diaphragm, to which it is fastened by the overlying peri- toneum (Fig. 25, L), and why it is itself excavated for receiving the abdominal viscera which rest against its surface, since this. would favor the rhythmical compression of the organ during; respiration for increasing circulation in it ; at the same time promoting the secretory functions and metabolic processes in the organ, which are very extensive. There is a reason for all the arrangements that obtain In short, the organ is sand- wiched, so to speak, between two opposing forces, notably the diaphragm and muscles in the abdomen ; while the intestines serve as a soft, elastic cushion for effecting the rhythmical compression under the force in the muscles during respiration, transmitting this upon it, and which, of course, increases its circulation correspondingly. And not this only, but all the other actions as well, inclusive of the intestines and the lymphatics or lacteal system and terminal duct. It also ad- mits of easy demonstration. For this purpose a dog was chosen, and several hours after the animal had been fed it was dis- patched, and the abdomen separated from the chest by division effected above the insertions of the diaphragm in the ribs, and was completed by severing the spine between the last dorsal and first lumbar vertebra, ligating the vena cava, oesophagus and thoracic duct for preventing escape of the contents. As will be seen, the abdomen separated from the chest forms an egg-shaped organ (Fig. 8b), the large end of the ovoid looking anteriorly, or toward the chest ; the small ending posteriorly in the pelvic basin in which it terminates ; the differentiation of this bony compartment having reference to the crural sup- ports for sustaining the posterior end of the trunk during locomotion, and of the body itself in the erect position, as in. man. The cava (B), oesophagus (C), and aorta, with the accom- panying duct (D), occupy the mid-region upon a line extend- ding from the sternum to the spine, with the cava a little to the right (left in the picture). And everything being ready, the stump of the cava was then snipped with a sharp pair of' scissors. The blood spurted with great force out of the vessel,, 222 THE FOECE TO THE PORTAL CIRCULATION. leaping ten feet, and as though shot out of a syringe, under the force in the abdomen ; but was not sustained, falling down immediately upon the diaphragm in a running stream. I then placed my open hand upon the convexity of the diaphragm, pushing it downward in imitation of inspiration, when the jet was renewed instantaneously, rising and falling with the increase and diminution of the pressure ; hence, there could be no doubt on earth that inspiration rushes the venous blood in the abdomen toward the lungs. Of course, a great deal of the blood had come from the lower cava system, rushing out of Fig. 83. — Transverse Section of the Trunk through the Inferior Margin of the Chest around the Circle of the Diaphragm, showing the form of the abdomen, which is egg-shaped, the large end of the ovoid presenting in the chest-excavation, the small in the pelvic basin, which forms the posterior end of the cavity. A, diaphragm ; 2?, stump of lower cava, ligatured ; C, oesophagus, ligatured ; D, thoracic aorta and thoracic duct, ligatured ; E, first lumbar vertebra ; F, lumbar muscles (quadra tus lumborum, etc.). both under the action of the elastic air-cushion, while the force transmitted from the containing walls, in imitation of the action in inspiration, increases it. In the first instance, the intra-abdominal pressure of itself was sufficient for producing the jet, showing it to be considerable. It should be mentioned here that the valves in the femoral veins obviate reflux in the lower extremities, so that the systole in the abdomen produced by inspiration should act as a lifting force upon the blood in the venous system, as well as the portal blood, the two being affected simultaneously. (We may remark, en passant, that THE FOKCE TO THE HEPATIC CIKCl LATIOJN-. 223 the presence of valves in the veins of the pelvic viscera has its explanation in connection with the special functions in these organs for obviating reflux during expulsive efforts which will come up further on.) In this manner, then, the abdo- men functions as a great ventricle upon the venous blood for forcing it toward the lungs during inspiration. That there might be no mistake, however, about the portal blood and the blood in the liver, I introduced my hand through an opening in the linea alba and compressed, first one, then another portion of the liver ; and every time I did this, and the moment I did it, the blood spurted out of the caval opening, showing conclu- sively, and beyond the shadow of a doubt, that inspiration increases circulation in the liver. Now, then, we can .readily understand why the hepatic veins are fastened to the liver- substance, being incorporated with it for maintaining patency in the canals, as this would favor venous efflux during, inspi- ration, the blood rushing out of every portion of the liver directly into the vena cava, in place of converging in a common trunk, as in the usual way ; the right, left and central por- tions emptying their blood immediately into the venous sys- tem. It is very pretty. Concerning the Relations which the Portal Vessels Sustain to the Hepatic Veins for Producing Correspondence and an Uninterrupted Flow of Blood through the Liver. Briefly, the portal vein is intercalated between two exten- sive capillary systems — one in the mucous membrane of the intestines, the other in the liver-substance ; consequently, the force in the arterial system can have but little effect upon cir- culation in the liver, which must have other force applied to it for making it commensurate with the physiological require- ments, and for maintaining correspondence with the absorptive processes in the intestines ; otherwise impossible. This, as we see, is made dependent upon respiration for producing rhyth- mical compression of the liver, and which is supplemented by the action in the portal vein itself, which is very muscular, and connected with respiration by means of the rich, nervous plex- uses embossing the vessels the same as the arteries, and, like them also, enabling an increase and decrease in the local "22± THE FORCE '10 THE HEPATIC CIRCULATION. actions by expanding and contracting the lumen, the portal vein dividing up in the liver exactly like an artery ; more- over, are free to move by reason of Glisson's capsule, and not fastened to the liver-substance like the hepatic veins. In short, they possess automatism, and being intimately con- nected with the solar plexus and pneumogastric nerves, should greatly expedite circulation in the organ during respiration, at the same time it constitutes the fine adjustment in this mechanics in correspondence with the universal rule ; other- wise, the local actions could not be carried on. In other words, the vessels have a separate sheath of their own in the liver, with the nerves extending over the vessels the same as in the cavity of the abdomen, and which certainly jus- tifies this conclusion. Furthermore, we have seen that dur- ing inspiration a wave of contraction pervades, first the arterial, then the capillary, then the venous systems, which, of course, would include the portal vessels, no reason pre- senting why it should not do so, but every reason for it, bringing it in correspondence with the systemic current, which the scheme calls for. And since respiration is all-per- vading, it is hardly to be doubted that such is the case. But this dependence of the portal circulation upon respiration calls for its check and balance also, in order to preserve equilibrium, which is furnished in the nervous plexuses that embrace the vessels, the strain to these, which is occa- sioned by over-distention, producing the reflex action for relieving it, and known as "sighing," which is simply an effort to relieve an overcharged portal system ; in this manner exciting the reflex actions in the medulla oblongata, or the same as regulates the actions in the lungs and in the heart, the whole connecting through and through ; otherwise, correspond- ence could not be produced for maintaining a balance in the circulation for conserving the functions. Its connection with mental causes is due to the fact that profound mental disturb- ance diverts nervous force from respiration for protracted periods, the blood in consequence accumulating in the portal vessels, till finally comes the deep and noisy inspiration for relieving it, which would also include the venous stasis in the systemic capillaries, as this, too, is dependent upon res- THE F0ECE TO THE HEPATIC CIECULATIOlSr. 225 piration. But any circumstance that should embarrass res- piration, mental or mechanical, would soon produce over-dis- tension of the portal vessels, and invoke this eff ort for relieving it. Hence, full diet, with sedentary habits, or tight corsage, as in the case of females, who are notorious for these sounds, preventing free action in the diaphragm, consequently pro- ducing engorgement, while free exercise and loose corsage are effectual remedies. It is very disagreeable, the more so be- cause deceptive, since it suggests pain when none exists, and if the ladies should release the abdomen and burn up the internal bandages, or put them on occasionally when they go from home, taking more exercise, too, we would hear no more from them in this direction. The whole trouble is in the abdomen, and freer respiration is needed for relieving it. But man has no monopoly of this action, since the very fishes, after remaining stationary for long periods, are seen to make this deep inspiratory effort, which compresses the viscera and flares open the opercula and branchiae at one and the same time, for relieving venous stasis, the principle in the mechanics being fundamentally the same as in the higher animals, due allowance being made for the stage in development. The connection of the muscles in the abdomen with the lower jaw causes it and the opercula to fly widely open at one and the same time, when the abdomen contracts for increasing pressure, thereby increasing the action in the branchiae, all the parts being fully coordinated in the medulla oblongata. The horse and ox, standing quietly in full digestion, are seen every now and then to take one of these deep inspiratory efforts, rocking forward so suddenly upon their feet as to rouse them from the doze. Anything which should hasten respiration, therefore, such as singing, laughing, talking or bodily exercise, would greatly expedite the portal circulation. Hence the trite saying ' ' Laugh and grow fat " is a truism in physiology, since the effect of the former is to pump the portal blood and lymph into the systemic current and produce fullness in the vessels, which favors the nutritive processes and the formation of fat. It was a sharp, true saying. The effect of the rapid pumping action in the abdomen in reducing the volume of the portal blood has forcible illustration in the 226 PHYSIOLOGICAL ANATOMY vocalist, who complains of "• a feeling of emptiness in the stomach," and rushes to the restaurant to till himself full again, eating ravenously to appease the appetite. The deep and long inspiratory efforts, followed by the long forced expi- rations, had literally emptied the portal circulation, as it were, also the viscera of the force-producing elements. In fine, for increasing the portal circulation it calls for rhythmical com- pression of the liver and portal vessels synchronous with respi- ration. The following beautiful cuts (Figs. 84, 85) show the mode of termination of the portal vessels in the inter-lobular veins, and Fig. 84. — Rabbit's Liver Injected, showing a portal branch, the vence inter-lobitlares, the capillary network, and a vena intra-lobularis in the centre of a lobule. — Frey. these again in the intra-lobular (Fig. 85, 3, 2, 1), or radicals of the open hepatic veins ; so that one. can readily understand why rhythmical compression of the liver should increase cir- culation in the venous channels, while fhe speed of the cur- rent thus produced would depend upon the energy in the respiratory rhythms. Of course, the action in the portal vessels should be considered as in connection with this, while the increase of pressure in the parenchymatous tissue promotes absorption, but increase in arterial pressure exerts no influence upon it (■ enersich) ;* hence, rhythmical com- * Ludwig's Arbeiten, 1871, p. 53. PH SIOLOGICAL A1STAT0MY. 227 pression of the liver during respiration is essential for expedit- ing absorption in the liver for maintaining this in corre- spondence with the absorptive processes in the intestines ; otherwise impossible. In this manner, then, the portal circu- lation is maintained in correspondence with the absorptive processes in the intestines and liver, the pressure produced by the gases, together with the respiratory rhythms, acting upon both alike for compelling this circumstance. In other words, the fluids in the parenchyma are pumped into their respective channels simultaneously with the fluids in the intestines. Pig. 85. — Transverse Section of a Single Hepatic Lobule. — Sappey. 1 , Intra-lobular vein, cut across ; 2, 2, 2, 2, afferent branches of the intra-lobular vein ; 3, 3, 3, 3, 3, 3, 3, 3, 3, inter-lobular branches of the portal vein, with its capillary branches, forming the lobular plexus, extending to the radicles of the intra-lobular vein. Finally, to this mechanics must be added the action in the heart, the diastoles in the right side serving to aspirate the hepatic veins, at one and the same time that they aspirate the venous system, the vessels also debouching in the cava close to the heart, whereby an uninterrupted flow is maintained in the organ, the same as in the lungs, but is not sufficient to make it uniform, the blood tending to accumulate during expiration ; and which affords opportunity for effecting metamorphosis, an amount of time being required for this purpose, which is also in correspondence with the action in the lungs — indeed, in every organ. 228 MUSCULAR FORCE FOR THE BILE. Concerning the Action in Bile. — Of course, the same mechan- ics apply for compelling the bile through the gall ducts as the blood through the hepatic veins, the force in respiration affect- ing both alike and simultaneously. But here also a special force applies for increasing the actions, ard interesting ana- tomical dispositions obtain for separating the bile fiom the blood, which it would be as well to mention in this connection. According to Professor Hering, the gall capillaries or intra- lobular gall ducts do not run along the boundary walls of the liver cells, but are incorporated with them, blending with the walls in which they lose themselves, as it were ; thus bringing them into intimate relations with the cell contents. Further- more, that the blood capillaries occupy the spaces between the cells upon the opposite side, the cell-substance intervening between them, the effect of the arrangement being to isolate the gall capillaries, separating them completely from the blood capillaries ; so that, when pressure is made upon the liver dur- ing inspiration, the blood passes in one direction, the bile in quite another, or opposite direction. It is very pretty. Now, then, to this must be added the special adjustments in the ducts for compelling movement in the bile, which in- volves automatic action in this tubular system, the same as the portal vessels and hepatic artery, with which they are inclosed inGrlisson's capsule, since they also require independ- ent movement in connection with their special functions, or the power to expand and contract upon the contents, which, of course, is intiuenced by nervous force propagated from the intestinal mucous surface during digestion, for compelling the secretions into the duodenum, at once the purpose of this arrangement. But as the biliary secretion is going on all the while, we have a special arrangement in the gall-bladder for storing the bile in the interim of digestion ; and this mechan- ics also contains several very interesting features. Thus, the gall-bladder occupies an elevated position against the liver- substance, to which it is fastened by an overlying layer of peritoneum and connective tissue fibres, while its neck is occupied by a spiral valve (Fig. 8 ), the whole whipped off to one side of the main hepatic duct. Hence, when the orifice of the duct closes during the interim of diges- MUSCULAR FORCE FOR THE BILE. 229 tion the effect would be to cause reflux of the bile up the cystic duct, the force in the diaphragm compelling this circumstance. Muscles and nerves to the gall-bladder also. Why % As we have already said, muscles and nerves are the provision for producing force ; hence, they must relate to the Fig. 86. — Longitudinal Section of Duodenum, showing tne crescentic folds of the valvulae conniventes, pancreatic, hepatic and cystic ducts, together with the spiral valve at the neck of the gall-bladder. — Gray. bile, for compelling it into the cavity during the interim of digestion, and for compelling it into the intestines in corre- spondence with the functions in the latter, muscular and nervous force being applied all along the line for increasing the actions and producing correspondence ; otherwise, this also 230 AUTOMATISM IN THE G ALL-DUCTS. would be meaningless. According to Iltnle, the coats of the gall-bladder are formed of layers of connected tissue, alternating with lamina? of unstriped muscles, the fibres crossing each other in all directions, the nerves for the most part springing from the solar plexus. It results from this arrangement in the parts that the gall-bladder, inclusive of the ducts, must be in- fluenced by resrjiration and the local actions, being under con- trol of the central nervous system and the local ganglia. And by looking closely into the mechanics, it is also easy to per- ceive how the action in the diaphragm should materially assist the ascent of the bile up the duct into the bladder. Notably, the gall-bladder is fastened to the liver while the terminal end of the common duct is inclosed in the walls of the duodenum, which is firmly secured to the spine by connective tissue, and the overlying peritoneum (for it would not do to have it sag- ging by the ducts) ; hence, the to-and-fro movements in the diaphragm with the mouth of the duct closed must produce reflux of the bile into the gall-bladder, the spiral valve serv- ing to assist the action, at the same time that it functions as the floor of support. It follows, however, that the ducts must contract and elongate with inspiration and expiration in order to obviate strain, otherwise inevitable, since the diaphragm oscillates as much as two inches, and which could not other- wise than affect the movement of the bile. At the same time, we must remember that there is automatic action in connec- tion with the flow, since the functions in the gut call for this, the sensory impressions produced in the mucous membrane by the food being transmitted to the special local ganglia for the purpose. It is all connected by nervous force for effecting coordination and producing correspondence in the local actions. The bile, then, flows down the ducts into the gut during digestion, responsive to the calls made upon it ; while during the interim it flows up the cystic duct, while the bladder ex- pands pari passu with the afflux, the same as the urinary bladder, or from sensory impressions in the mucous membrane produced by the bile. Hence, it is easy to perceive how it should become enormously distended with the bile when greatly in excess of the wants in the digestive processes ; not that it is forcibly distended by the action in the diaphragm and gall- RHYTHMICAL COMPRESSION OF THE PANCREAS. 231 ducts, any more than the urinary bladder is distended by the action in the ureters and kidneys, which cannot be thought of ; but that the organ expands till it can expand no more, and pain is produced by the traction upon the nervous fila- ments. We might mention here the existence of the close capillary plexuses in the mucous membrane of the gall-blad- der, which would effect rapid absorption, so that the bile soon becomes thick and viscid ; hence, cannot be retained long at a time without danger of becoming inspissated, producing gall- stones. Concerning the Action in the Pancreas. — Taking up the circumstances in anatomy as we go along, the pancreas comes next in order, its duct emptying into the bile duct (sometimes opening independently in the gut), the separate secretions thus intermingling in the common duct previous to debouching in the duodenum (Fig. 86). Why the two fluids should be thus intimately admixed, bringing them together as speedily as possible before undergoing admixture with the chyme, must have reference to interchanges between them, whereby they gain in effectiveness, which would be the natural explanation ; but what they are, chemical or otherwise, 1 am not prepared to say, only throwing out the suggestion that the circumstance gives rise to. The organ is conical in shape, the broad end or base, known as the "head," abutting against the gut, which bends around it, above and below, embracing it (Fig. b7), while the long, tapering body extends across the crura of the dia- phragm behind the stomach to the spleen attached to the great end or cut de sac of the stomach, where it terminates in the tail. It results from this arrangement in the parts that the organ is rhythmically compressed during respiration, the same as the liver, both simultaneously, which should cause the secretions to flow out at one and the same time with the bile, and, like it, also flowing from high to low pressure, since the churning action in the duodenum connected with its func- tions must inevitably determine low pressure around the ter- minal duct with every expansion in the gut. Then, again, the churning action in the stomach itself should effect changes of pressure in the gland for promoting the discharge of the secre- tions. 232 AUTOMATISM IN THE PANCREAS. Finally, we have to mention the automatism in the gland cells and discharging ducts, without which nothing could be accomplished in the secretory processes ; while this in turn is connected with the action in the gut by means of the special nerves and ganglia for unifying and coordinating the movements, the same as the liver and bile ducts, whereby uniformity is produced throughout, otherwise impossible ; the pancreatic secretions being controlled by sensory impressions in the mucous membrane, produced by the food, the same as Fig. 87.— Pancreas and its Relations.— Gray. the hepatic, and salivary glands with which it is homologous, the structure being the same or racemose. All of which is plain enough. Concerning the Action in the Spleen. — That the spleen pos- sesses certain powers of expanding and contracting in connec- tion with the functions in the organ, there is small room for doubt, for the following reasons — namely: 1. The investing capsule forming the framework of the oraan (giving off the cords or trabecular, in which the parenchyma or splenic pulp is situated — being traversed and inclosed by the trabecular — and PHYSIOLOGICAL ANATOMY OF THE SPLEEN. 233 passing in at the hilus with the vein and artery, incloses them also) is homologous with arterial structure, being composed of fibro-elastic tissue and muscles. Elastic tissue fibres are abundantly intermixed with connective tissue fibres in the outer or external portions of the capsule, while the deeper or internal portions are rich in unstriped muscle fibres, which are interspersed with the cords or trabecule through the parenchyma, and being inserted into the walls of the veins with which the trabeculse are incorporated, it is manifest that contraction of those fibres would have the effect of flaring open the veins, and expansion the oppposite effect ; while contrac- tion of the envelope itself should condense the spleen and drive out the blood in the veins, expansion would have the opposite effect. But with the actions coordinated would make it still more effective for compelling the venous blood in and out of the organ; and the terminal ends of the veins being open, the whole cell- structure, the lymphoid follicles, and Malpighian corpuscles are thus bathed in the portal blood brought into them by this action in the gland. In short, there must be some reason for the presence of elastic-tissue fibres and muscles in the gland, and the special relations they sustain to the veins. 2. The walls of the veins, where they enter the hilus, and for some distance in, are very thick and dense, by reason of being incorporated with the trabeculse, blending together ; while in the case of the artery and its branches, the walls are not joined to the trabeculse, but the vessels are contained in a loose sheath of areolar tissue, thus allowing free action in them, ' which is essential to the life in the cell-broods of the lymphoid follicles and Malpighian corpuscles, enabling them to increase or diminish the supply of arterial blood for maintaining the life that is in them, and fulfilling their proper functions ; in- creasing or diminishing the actions upon occasion in response to nervous stimulus, in correspondence with the universal method. In short, there must be some special reason for the anatomical dispositions that obtain in the arteries as well as in the veins, for they cannot be purposeless. 3. The great relative size of the veins, which is greatly in excess of the arteries, the same applying for the trunks of the 234 PHYSIOLOGICAL ANATOMY OF THE SPLEEN. vessels, the splenic vein being a number of times larger than the artery ; there must be some reason for this also, for it neither can be purposeless. And there can be but little doubt that the organ functions as a reservoir for relieving an over- distended portal system, expanding during this time under special stimulus, and thus diverting the blood from the liver, and so relieving it. It would account for the elastic tissue fibres and the muscles in the spleen, together with the special arrange- ments in the walls of the veins in the spleen Furthermore, we know the organ does rayjidly increase in size in acute febrile disorders, from the congestions they produce in the Fig. 88. — Transverse Section of the Human Spleen, showing the distribution of the splenic artery and its branches. — Gray. liver and portal system ; nor is it possible for this condi- tion to be produced by the action in the vein simply, the organ absolutely inhibiting it ; the walls of the vein yield- ing long before the dense structures in the spleen. Besides, it would involve the whole portal system. It cannot be thought of. The sharp pain in the left side, induced by running, has its explanation in an over-distended spleen, the organ rapidly expanding for relieving a surcharged liver and portal system, thereby pulling upon the nervous filaments and producing pain, just as an over-distended bladder pioduces pain, only the one is more rapidly produced than the other, and the pain sharper. Finally, the simple experiment of MUSCULAR FOECE FOE THE SPLEEN. 235 dipping the spleen into warm water condenses the organ ; the galvanic current also ; though by reason of the density of the structure the action is necessarily slight ; hence, there can be no doubt that it also expands. Moreover, the vessels are em- bossed by a dense plexus of nerves connecting with the solar plexus, which at once shows that there must be great activity in the organ ; otherwise, it were all meaningless. The special anatomy is deeply interesting, but it is difficult to produce Fig. 89.— Oae of the Splenic Corpuscles, showing its relations with the blood vessels. — G-ray. a, Arterial twig, embracing a Malpighian corpuscle. The terminal branches of the splenic vein are seen losing themselves in the corpuscle, in which they open a mental picture of it ; indeed, altogether impossible, though some general idea may be formed. The lymph follicles, cells and Malpighian corpuscles are in close and intimate relations with the arterial vessels, as a matter of course, the arterial capillaries surrounding them (Fig. 88). The manner in which the veins lose themselves in the Malpighian corpuscles, and the intimate relations they sustain to the arterial feeder, are very forcibly shown in the following beautiful cut (Fig. 89, a). 236 ABSENCE OF VALVES IN THE PORTAL SYSTEM. For the rest, the reader is referred to the literature of the sub- ject and works on histology. The portal system is brought into prominence in the follow- ing beautiful cut (Fig. (J0) for impressing the special anatomy upon the mind. It would seem a bold thing to disconnect the viscera from the containing walls in order to increase the action in them, and to send the vessels and nerves to the organs over floating ligaments ; but a bolder one to break up the portal veins into a second capillary system in the liver, threading it in every direction and supplying every cell with the fluid, and as though the vein were itself an artery with the force of the heart at its root, as in the aorta, whereas the heart is far removed, the vessels floating in a ligament and a capillary barrier between, to be re-collected through the radi- cals of the hepatic veins that debouch in the lower cava, and to send the vast bulk of the alimental fluids over such a route, the organism itself depending upon it : there is a problem for you, but all worked out and open for inspection. But the solution is only possible upon the basis of the fundamental law underlying the organism and autonomy in the structures, the local actions intimately blending with the systemic mechanics, by means of the nerves leading out of the solar plexus, in which the visceral nerves converge (Fig. 108, 5, 2, 1 ), this connecting with the respiratory and vaso-motor centres through the pneumogastric (Fig. 109, 2) and great splanchnic nerves (3, 3), together with the pumping actions in the lungs, heart, arteries and capillaries, inclusive of the force in the ven- ous system ; the whole coordinated through the medulla oblon- gata, whirls it over the road-bed in the vascular lines with such expedition as to make the journey within a minute from the cavity of the stomach. But all plain enough in the light of the law that applies and automatism in the tissues, the muscular and nervous forces swelling at the difficult points for compelling the passage and completing the circuit ; otherwise is utterly inexplicable. There is more ! In all the expanse of venous territory in the portal system, not a valve presents. Why ( The answer is not far to seek. The presence of a valve in the portal vein would prevent reflux, so that congestion of the liver could ABSENCE OF VALVES IN THE POKTaL SYSTEM. 237 not find relief in copious transudations in the intestiual canal, producing diarrhoea, thereby conserving liver-structure, which, is the object of this arrangement, and would inevitably end in disaster. Indeed, we have example of this in the partial constrictions which occur in the liver from hyper- Fig. 90. — Portal System in Diagram. — Gray. The transverse colon is removed, the- duodenum divided near the pyloric orifice and the stomach pulled aside, in order to expose the vena portse, with the mesenteric arteries omitted, for better definition of the mesenteric veins. plasia of connective tissue produced by alcohol, interfering with the course of the blood through the liver, tending to dam it back in the portal system, leading to diarrhoea and. effusions in the cavity of the abdomen, producing the drunk- ard's dropsy. But with valves in the veins, this reflux could- not occur, and life would have a speedy termination, clos- 238 ABSENCE OF VALVES IN THE PORTA L SYSTEM. ing upon it, sharp and terrible as the jaws of a mastodon. It is well, then, for the drunkard that there are not valves in the portal vein; while temporary congestions of the liver are passed over and never known, finding prompt relief in copious evacuations through the bowels. And it is no wonder that purgatives are so much lauded, since overfeeding is extremely- liable to overload the portal system, while purgatives effect rapid depletion, thereby restoring the balance, and everything runs on as before. JSrot at all strange. But it would be far better to stop short of gluttony, and not overrun the capacity in the mechanics. Abernethy was very close to the mark : "Half of the diseases come from fretting, the other half from stuffing."' The fir.-t we can readily understand, from the effects it must inevitably exert upon the local and systemic actions, from the diversion of nervous force it must inevitably produce, tending to engorgements and disaster ; the second has already been considered. In conclusion : The soft, compressible portal veins spread out in the viscera could not otherwise than undergo rhyth- mical compression during respiration, which should tend to force the blood along the channels in the liver with corre- sponding energy ; this, together with the actions in the ves- sels in connection with respiration and the functions in the liver, constitutes a dual foive for speeding the blood through the liver, comprising the coarse and fine adjustments in this mechanics in correspondence with the universal rule, muscu- lar and nervous force applying everywhere for speeding it through the channels. And with this arrangement in the parts, we can readily understand the rapidity in the absorptive processes in the stomach ;* otherwise is utterly inexplicable. The force in the stomach for compelling it in the vessels, the force in the walls of the abdomen and portal vein for com- pelling it through the liver, and, finally, the force in the pump- * Thus, in a case of extra version of the bladder observed by Professor Erich- sen (Medical Gazette, Vol. XXVI., p. 363), in which the urine could be col- lected immediately, it was found that when a solution of ferrocyanide of potassium was taken into the stomach, the salt was detected in the urine in one instance within one minute, and in three other instances within two and a half minutes. .A), so that during inspiration this is pulled away from the aorta at the same time that it compresses the oesophagus upon the left in the upper arc. It results from this arrangement, therefore, that the aorta is relieved from pressure during inspiration, while there is progressive increase of press- ure upon the oesophagus, the necessity for which has already been given. Finally, looking from the aortic to the vena caval opening, we find that the same principle in mechanics is maintained here also. For example, this opening occurs at the point of junc- ture of the middle and right leaflets in the central tendon, while the muscular layers that have insertion in the right aor- tic arc have their points of origin upon the left of the vena cava opening (Fig. 92) ; hence, when these muscles contract during inspiration, they must inevitably pull upon the left side of this 1 nin en and flare it open, at the same time relieving the aorta by pulling upon the lower arc. Then, again, upon the right or external side of the vena cava opening, we have the hori- zontal muscular fibres connected with the inferior ribs (JS ), for pulling upon this edge of the lumen simultaneously during inspiration, and throwing the flood-gate wide open for afford- ing ready egress to the large amount of blood flowing into the lungs during this time, the muscular layer (o) upon the left of the middle leaflet pulls also upon the caval opening. In the band of fibrous tissue which skirts the opening anteriorly {F, N), we have a needed brace for obviating strain from the too energetic action of the powerful muscular bundles, especially from the one to the right of the oesophagus, which would tend to pull upon this portion unduly, and twist it upon itself, and so disarrange the parts during inspiration ; hence this strong brace of fibrous tissue. Nothing could be more beautiful than these dispositions of force, with the systematic arrangements in the structures for accomplishing the important ends in view. It is comprehensive and superb mechanics. The ligamentous arcs, formed over the psose and quadrati lum- borum muscles, are constructed upon the same principle, so as not to interfere with their functions or the splanchnic nerves. The ligamentum arcuatum internum, which is thrown PHYSIOLOGICAL ANATOMY IX VEINS. 243 across the upper part of the psoas maguus muscle on either side, is connected by one end to the outer side of the body of the first (occasionally of the second) lumbar vertebra, and by the other to the front of the transverse process of the second lum- bar vertebra ; while the ligamentum arcuatum externum, thrown across the quadratus lumborum, is attached by one extremity to the apex and lower margin of the last rib, and by the other to the transverse process of the second lumbar vercebra, with which the ligament for forming the opening for the splanchnic nerves also connects. It is all very prettily arranged. Adjustments in the Lower Cava. — We now have to note the adjustments in the walls of the lower cava with the action in the diaphragm. We have seen that during deep inspira- tion the diaphragm descends as much as two inches ; hence, did not some adjustment obtain in the walls of the cava, the canal would be bent upon itself during this time and obstruct the blood, when the purpose is to expedite the flow of venous blood to the lungs, thereby bringing all the arrangements in the diaphragm to naught. On the other hand, during forced expiration, and the elevation of the diaphragm in the chest cavity which this produces, it must inevitably subject the lower cava to a degree of traction terrible even to contemplate. Besides it should greatly reduce the lumen, thereby obstruct- ing the flow of blood were the vessel capable of enduring such rude mechanics, which cannot be thought of for a moment even. Now, then, for obviating these circumstances, we have the great- increase which occurs in the longitudinal muscles in the walls of the lower cava, adjacent to the diaphragm, together with the nerves for connecting it with the solar plexus, pneumogastric and phrenic nerves for coordinating it with the action in the diaphragm and respiration, so that it contracts the longi- tudinal axis during inspiration, at the same time the lumen is thrown more widely open, both within and below the dia- phragm, by expansion of the transverse muscles, the mus- cles in the diaphragm contracting ; and vice versa during ex- piration, the vessel elongating pari passu with expansion in the diaphragm, thereby obviating traction ; hence, these muscles and nerves to the lower cava for coordinating it with 244 PHYSIOLOGICAL ANATOMY IN VI INS. respiration and the action in the diaphragm. But in the portion of the cava above the diaphragm, adjacent to the heart, the muscles are absent for two reasons : For the reason that the lungs and heart move downward during inspira- tion, and upward during expiration, moving together and simultaneously ; which compels the upper cava and primitive branches to elongate and contract in similar manner with the oesophagus and lower cava, only the action alternates in the two localities, those above the diaphragm elongating as those below it are contracting, and nice versa ; and the anatomical disposi- tions for effecting the actions are perfect, for the upper cava and primitive branches are similarly endowed with the oesophagus and lower cava system, possessing both longitudinal and circular muscles. 2. For the reason that strain tends to fall in this local- ity, produced by reflux in the right ventricle during the systole, and the weight of the fluid from above meeting the force in the diaphragm from below, making this the point of resist- ance, subjects the vessel to unusual pressure, especially dur- ing expiration, when the blood tends to dam at the right side of the heart; hence the dense fibrous tissue in this portion of the lower cava for resisting strain. But we may remark, en passant, that the absence of the muscles does not neces- sarily imply a totally passive condition, since the same deduc- tion would have to be made for the entire venous and arterial systems, by reason of the intima, or elastic inner coat, and the fibrous and elastic ti sues in the outer coat, only that muscles are essential for increasing force and producing energetic action. Finally, this disposition of the muscles in the walls of the lower cava, as the necessary physiological adjustments with the action in the diaphragm, would account for a similar arrangement of the muscles in the renal veins, since the kid- neys, by reason of their lying against the diaphragm, are also made to oscillate with respiration, moving to and fro upon the soft cushions of fat in the long axis of the body ; and did not a similar arrangement obtain in the renal veins, these also must inevitably be seriously affected by the to-and-fro movements ; hence the numbers of the longitudinal muscles and nerves in the walls of the renal veins, together with the nerves for connecting them with the solar plexus and pneu- ELONGATION AND CONTRACTION IN VESSELS. 245 mogastric nerves, for coordinating them with respiration, with which the renal functions are also necessarily connected ; and looking thence to the vena porta and its tributaries (since a.11 the viscera with which they connect oscillate in similar manner with respiration), we see that this anatomical arrangement is maintained throughout, the whole being rich in longitudinal muscles. But perhaps one of the most striking illustrations of this function in the vessels occurs in connection with the splenic vein, which has adjustment with the functions in the stomach. For example, the spleen is attached to the great €ul de sac upon the left, with the vena portse at the liver (Fig. 87); consequently when the stomach is distended with ingesta, the splenic vein is fully twice the length it has in the interim of digestion — is not pulled into extension by the dilat- ing stomach, but elongates pari passu with it ; otherwise, there would be prodigious strain, ending in inevitable disaster. Accordingly, we find the splenic vein exceedingly rich in longitudinal muscles ; whereas, the splenic artery adjacent is nearly destitute, the muscles being nearly all circular. In consequence, during the interim of digestion, when the splenic vein is little more than half its length when the stomach is full, the artery is thrown into serpentine folds, or the form it presents in the dead body ; the vein measuring upon an aver- age less than five inches, while the artery approximates nine inches. But when the stomach is full they are both of the same length ; hence, there can be no doubt that the great elongation and contraction in the vein is due to the number of the longitudinal muscles, which corresponds with the ac- tion in the leech, with which it is homologous. In the case of the renal artery, however, the matter is again different ; here we have longitudinal fibres in abundance, in correspond- ence with what occurs in the renal vein, to enable the lateral movements in respiration, while its powers of elongating and contracting are readily inferred from what occurs in the arteria dor sails penis during states of erection and quiescence ; since the arrangement of the muscles is fundamentally the same in both, the vessel elongating and contracting with the penis by means of the longitudinal muscles. Thus, it is perceived that adaptation of means to ends pro- 240 ELONGATION AND CONTRACTION IN VESSELS. duces correspondence in the structures, whether it relate to respiration or the action in the penis ; but remote as these functions would appear to be from each other, they both sus- tain the same relation to the organic laws, compelling similar arrangements in the structures, in order to produce the actions, as must appear obvious. And it is the same in every stage in development and every organ in the body, contrasting structure with structure, and function with function ; as also in widely separated organs and functions where similar ac- tions are called for, the same laws applying universally, and adaptation of means to ends must be in correspondence, in the very nature of things. CHAPTER XI. AUTOMATISM IN THE LYMPHATICS AND THE MECHANICS FOB CIRCULATING LYMPH. The Lymphatic System Intercalated between the Arterial and Venous Systems, Arising in the Tissues and Debouching in the Veins at the Root oi the Neck — The Dual Functions in these Organs Concerned in Drainage and Hsematosis — The Vessels Connecting with Respiratory Movement in the Tissues, Expanding and Contracting with the Blood-Capillaries by Means of the Nervous Connections Subsisting between Them — The Action in the Larger Vessels and Gland -Structures — Muscles and Nerves to the Organs for Producmg the Actions — The Action in the Lacteal System and the Manner in which it is Affected by the Action in the Gut for Compelling Rapid Movement of the Fluids in the Vessels — The Relations which this Sustains to Inspiration and the Action in the Venous System — Physiological Experiment Proving that Inspiration Pumps the Lymph into the Venous System simultaneously with the Portal and Hepatic Blood — Proof of Automatism in the Vessels. The lymphatic system is intercalated between the arterial and venous systems, taking its rise in the tissue spaces and interstices and emptying into the venous system at the root of the neck, at the junction of the subclavian and jugular veins (Fig. J 00). The left trunk, much larger than the right, and known as "the thoracic duct," receives the chyle and the lymph from the lower portions of the trunk and inferior extremities, inclusive of the left upper half of the body ; the right, known as "the right lymphatic duct," a small trunk of about an inch in length, receives the lymph from the right side of the head, right arm, right side of the body, inclusive of the con- vexity of the liver, right lung and right side of the heart, the orifice guarded by two semilunar valves fur preventing ingress of the venous blood ; the left is similarly guarded. According to Recklinhausen, the lymphatics function as a drainage system for the tissues, the particles too large to pass the stomata in the capillaries making their way through the open ends of the lymph-channels with which the tissue-spaces communicate, the tissue-spaces being as so many lymph- 248 RHYTHMIC MOVEMENT IN LYMPHATICS. lacunae. It seems 'reasonable only that the drainage is unduly interrupted by the numerous glands thrown across the chan- nels in which circulation is extremely difficult, the dense structure inhibiting rapid movement. Then, too, there are the thymus and thyroid glands, supra-renal capsules, and spleen of similar nature to be accounted for, which are inexplicable by this theory. Let it be, however, for Ma- ture is utilitarian to the last degree, and may combine two schemes — blood-making with tissue drainage — in this man- ner working the old products for a new role in the organ- ism, in the genesis of white corpuscles for tissue-structure and other purposes ; the matrix in the gland-structures, the slow circulation and rich materials conducing to the nutritive processes, thus serving as the womb of the tissues, so to speak, life springing out of the ashes, and ready to commence again the labor of living. Mirabile ! Without entering into the mooted question of the mode of origin of the lymphatics, whether by a closed network of capillaries (larger than blood-capillaries), or in the hue wall-less spaces in the tissue interstices traversed by the fluids to and from the cell-brood and blood-capillaries, matters not in the argument. What immediately concerns us is the force of this circulation for compelling the lymph through the channels in the measure of the physiological requirements in the tissues and lymphatic glands, which it has to traverse on its way to the venous system, together with the manner of coordinating the vessels with the blood-vascular system, for producing con- tinuity in force and a continuous current with the blood- stream, which the scheme calls for •; at the same time, main- taining automatism in the vessels and glands, which must not be lost sight of for a single moment, all the others depending upon it. The mechanics is easily understood. Thus, when the blood-capillaries expand for reducing pressure within themselves and increasing it in the tissue interstices (pp. i7o- 178), in order to compel the fluids into themselves, the lymph- vessels also expand simultaneously, the same nerves and nerve- ganglia acting upon all alike, so that they get their share of the tissue fluids. But, being larger than blood-capillaries, the action is necessarily slower and more difficult, but is sufficient KHYTHMIC MOVEMENT IN LYMPHATICS. 249 to determine the coarser particles, which were too large to pass the stomata in the more energetic blood-capillaries, into them- selves, floated into them upon waters, the medinm of transpor- tation ; passing in through the open lumen in the tissue-spaces or th^ larger stomata in the capillary walls, in the absence of these open ends to the lymph-vessels ; while during the sub- sequent contraction the valves obviate reflux, so that suction- force is made effective upon the fluids in the tissue interstices, and no reason presents why it should not. .\nd the vessels being composed of the same material as the blood- capillarieSj namely, protoplasmic substance, and connected with them by nerves, the respiratory movement in the tissues should affect both alike ; hence, it should have the effect of pumping the lymph into the lymph-channels simultaneously with the fluids in the blood-capillaries, the same law applying to both. In this manner, then, the lymph passes into the lymph-channels during expansion in the vessels, and the high pressure this produces in the tissue interstices, inclusive, of course, of the action in the blood- capillaries, the fluids flowing from high to low pressure ; while during the subsequent contraction the valves would obviate reflux, at the same time pushing the fluid up the channel toward the glands intercalated in the vessels by a series of rhythmical expansions and contractions similar to what occurs in the gullet, with which the vessels are homol- ogous, due allowance being made for the special adaptations with the functions in the organs. Moreover, Heller * has seen the lymph-vessels in the mesentery of the guinea-pig ex- ' pand and contract regularly and rhythmically. Then, again, the veins contract for pushing the blood toward the heart and lungs, and no reason presents why the lymphatics may not do likewise ; seeing, also, that they connect with the vaso-motor and respiratory centres, the same as the blood vascular system. Finally, the great difficulty in circulating lymph, by reason of the glands intercepting the stream, would account for the strength of the vessels, or the number of mus- cles, elastic and fibrous tissue in the walls of the vessels. Just here it were well to give some idea of the anatomy in the * CM. Med. Wiss.. 1869. p. 545. 250 PHYSIOLOGICAL ANATOMY. glands to show the difficulties which beset the way, and the necessity for this increase of force for compelling circulation in the measure of the requirements. In the first place, the glands are composed of a congeries of lymph-nodes communi- cating with afferent and efferent vessels (Fig. 93,/,/, h). 'J he i— \ Fig. 93.— Section of a Small Lymphatic Gland, half diagrammatically given, with the course of the lymph, a, The envelope ; b, septa between the follicles or alveoli of the cortical portion ; c, system of septa of the medullary portion, down to the hilus of the organ ; e, lymph-tubes of the medullary mass ; /, different lymphatic streams which surround the follicles, and flow through the interstices of the medullary por- tion ; g, confluence of these passing through the efferent vessel ; h, at the hilus of the organ — Frey . Fig. 94. — Follicle from the Lymphatic Gland of a Dog in Vertical Section, a, Reticular sustentacular substance of the more external portion ; b, of the more internal, and c, of the most external and finely webbed part on the surface of the follicle ; d, origin of a thick lymph-tube ; e, the same of a thinner one ; /, capsule ; g, septa ; k, division of one of the latter ; i, investing space of the follicle with its retinacula ; h, vas afferens ; I, I, attachment of the lymph-tubes to the septa — Frey. PHYSIOLOGICAL ANATOMY. 251 internal arrangements, as far as made out, are substantially as follows : From the investing capsule, composed of fibrous con- nective-tissue intermixed with numerous smooth muscular fibres, septa (5, c) corresponding with the number of the lymph- nodes are given off, composed of the same materials as the capsule, and pass through the gland (c) to the hilus, investing each of the nodes and forming a similar capsule around them also (Fig. 94,/, g), while in the nodes themselves the numerous minute individual follicles of which they are composed are surrounded by reticular tissue (Fig. 94, a, 5, c), which serves the purpose of a capsule to them also (/), the whole thus connect- ing through and through, since the reticular tissue of the fol- licles connects with the septa {i, i) forming the sustentacular tissue, the lymph-tubes also connecting with the septa (Z, I). •'But no follicle is completely ensheathed at its under surface in this system of septa. On the contrary, either one or several gaps, or even wide deficiencies, are left, through which the follicular tissue comes into immediate contact with the medul- lary substance. In the same way, the partitions passing in- ward between adjacent follicles may be interrupted by massive bridges, as it were, of lymphoid tissue, by which these are con- nected one with another, the muscular fibres being present in large numbers" (Frey).* Then we have the lymph-tube, with its complicated system of vessels (Fig. 95, a),f traversing the reticular spaces beticeen the follicles and the investing reticular septa (d, d), so that a continuous passage is effected by the lymph at the same time that it is brought into intimate relations with the follicles, for effecting interchanges between them. Finally, we have a system of arterial and venous capillaries setting in and out of the gland in such manner as to bring the blood into iniimate relation with the follicles and gland- tubes (Figs. 96, 95), the gland-tube itself possessing its own system of blood-capillaries, so that blood circulates freely through the gland, and in the measure of the physiological requirements, so that every cell can get its due supply of arterial blood, as in every other organ. Now, then, what can be the purpose of all this capsular investment, with the mus- cular fibres richly interspersed, other than to effect rhythmical * Histology and Histochemistry of Man, p. 408. f Ibid., Fig. 404. 252 PHYSIOLOGICAL ANATOMY. changes of pressure in the follicles and lymph-channels for expediting circulation in connection with the special functions in the gland, seeing that muscular structure is for producing force, here as elsewhere ? According to /Schwartz, the muscles of the capsule at the Fig. 95.— From the Medullary Substaa jo of the Inguinal Gland of the Ox (after His) . a. Lymph-tube with its' complicated system of vessels ; c, portion of another : d, septa ; b, retinacula stretched between the tube and the septa. ^,JU> Fig. 96. — Transverse Section through the Equator of three Peyer's Patches of the same Animal, a, The capillary network ; b, of the larger circular vessels.— Frey. Ml'SCLES.TO LYMPH-GLANDS AND TESSELS. 253' line of junction of the medullary and cortical portions have a principally radiating arrangement, which is precisely what is needed for constringing the gland by producing contraction in. the muscles, and. vice versa, during expansion ; while the septar passing inward between the nodes with the broad bases at the capsule (Fig. 88, 5), and splitting up into numerous septa and coming together again for embracing the follicles for applying a special force to them, which the functions call for, consti- tutes the fine adjustment in this mechanics, in correspondence with the universal rule, the difference being only in adap- tive changes with the functions in the gland, which follows as a matter of course. This, together with the force in the af- ferent and efferent vessels, is sufficient to produce circulatiou through the glands, the force in the chest and arterial system also applying ; but is not the force in this circulation, being too far removed for overcoming the difficulties in the glandu- lar circulation, the force being upon the ground where the work is done in the gland-structures and intercommunicating vessels. Moreover, the vessels themselves bear testimony to this circumstance in the number of the valves they contain, which are strung like beads (Fig. 9?) along the vessels, and the number of muscles and nerves to them for producing action upon the lymph by means of the rhythmical expan- sions and contractions taking place in them, and acting in this respect as so many hearts upon the stream, each one representing a little ventricle or cardiac chamber for the pur- pose ; else this also would be meaningless. Moreover, Heller has observed such movements in the lymphatics of the mesen- tery, as has already been observed. Turn we now to the lacteal system and the lymph-channels of the mesentery for further corroborative evidence of the principle which applies, here as elsewhere in the organism,, individualism pervading the whole of it, and must do so in the very nature of things, in order that the vessels and glands may perform their functions and maintain existence, while force is added in the measure of the physiological require- ments. For example, contrast the action in the villus with the special anatomy in the lymph-channels in order to see' adaptations of means to ends beautiful to look upon. ln_ the: 254 MUSCLES -AND YALYES TO LYMPH-VESSELS. first place, we have the central lymph-channel (Fig. 9 ', I) in- closed in muscular walls (m), running the entire length of the channel, forming the sides over which the pavement epithe- lium is spread, the muscles extending from the muscularis mucosa? at the base of the villus. ^ow, then, when the muscles contract, the effect is to drive the lymph into the lymph-channels under the muscularis mucosa? {rete amplum) (Fig. 99, &), the force in the muscles compelling it. On the Fig. 97. — Showing the Number of the Lymph- Valves, with the Local Dilatations in the Yessels in the Warm-Blded Animals. — Sappey. other hand, when the muscles expand, the low pressure this produces in the channel aspirates the lymph ; then another contraction followed by another expansion, and so the little mechanism runs like a heart for pumping the lymph into the lymph-channels below. But to this we must add the force in the muscular walls of the gut for compelling the fluids into the columnar epithelial cells through the sieve-like open- ings upon the free surface ; thence through the memorana propria (e, e, e' ) into the interior of the villus, the high pres- sure it produces in the intestine, together with the actions in the villus and the epithelia (for they are all connected by nervous MUSCLES TO LACTEALS. 255 force) compelling this circumstance. No wonder, then, that fat or anything else absorbable should be rapidly absorbed. And there is no necessity for endowing any portion of the mechanism with extraordinary powers in order to account for the circumstance, such as that the epithelial cells act like #■ Tiff i Fig. 98. — Diagrammatic Section of a Villus. — Watney. ep, Epithelium only partially shaded in ; I, central chyle-vessel — the cells forming the vessel have been less shaded to distinguish them from the cells of the parenchyma of the villus ; m, muscle fibres running up by the side of the chyle- vessel. It will be noticed that each muscle fibre is surrounded by the reticulum, and by this reticulum the muscles are attached to the cells forming the membrana propria, as at e', or to the reticulum of the villus. Ic, Lymph corpuscles, marked by a spherical nucleus and a clear zone of protoplasm ; I', upper limit of the chyle-vessel ; e, e, e', cells forming the membrana propria. It will be seen that there is hardly any difference between the cells of the parenchyma, the endothelium of the upper part of the chyle-vessel, and the cells of the membrana propria, v, Blood-vessels ; z, dark hue at the base of the epithelium formed by the reticulum. It will be seen that the reticulum penetrates between all the other ele- ments of the villus. The reticulum contains thickenings or "nodal points." The diagram shows that the cells of the upper part of the villus are larger and contain a larger zone of protoplasm than those of the lower part. The cells of the upper part of the chyle-vessel differ somewhat from those of the lower part, in that they more nearly resemble the cells of the parenchyma. 256 MUSCLES TO LACTEALS. amoeba) and eat the fat.* But in my heart of hearts I thank the distinguished author for the large individualism in the cells and tissues it shadows forth, and he, of all men, is closest to the mechanics in the animal organism. But the amoeba must yield up some of its license in the compound organism for the common weal, and must take a subordinate position in blending with the common functions with which their actions are coordinated. And in the case before us, it is not compelled to extend branched processes into the canal for embracing the food, but only to expand the oral orifices or sieve-like openings, while the food is pushed into them under the force in the gut, the body of the cell expanding in order to receive it ; in consequence, the epithelia rapidly become double their size, and of a milky appearance from the amount of fat and other aliment they contain. And if Professor Foster meant this, we are in full accord; but I do not think he included the pressure in the gut for assisting the action. We have but to follow the lymph to the channels be- neath the muscu1 arts mucosa to see how the force in the gut applies to this also, together with the force in the numerous muscles forming the walls of the lymph-vessels, by means of which the local action is increased and the stream regulated with the capacity in the mesenteric glands, with which, of course, it must have adjustment ; otherwise, choking and engorgement would follow as an inevitable sequence of excess- ive action in the lymph-vessels. The following beautiful illustration, f from Teichmann, on the lymphatic system, will serve for impressing the matter. For example, the lymph- channel (there are several given here) in the villus debouch into the close-meshed lymph-vessels {rete cuu/ustum) be- neath the muscularis mucosce (not given in the picture) at the base of the villi (a, b), which rapidly expand into great lymph- chambers (c), in contact with the muscular cylinder (g, h), through which the efferent vessels (d, d) pass to get beneath the peritoneal layer of the gut in order to reach the mesen- teric glands, situated in the folds of the mesenteric ligament. * A Text-Book of Physiology, p. 819. M. Foster, M. A., M. D., F. R. S., Prae- lector in Physiology and Fellow of Trinity College. Cambridge, f Ludwig Teichmann, " Das Saugader System." Leipzig. 1861. MUSCULAR FORCE FOR THE LYMPH. 257 Finally, that the lymph-vessels and chambers are muscu- lar organs provided with valves for obviating reflux, and furnished with nerves from the adjacent ganglionic layers (Meissner's and Auerbach's, which we will come to presently) for producing the rhythmical expansions and contractions which occur in them, and which also connect with the great pumping movement in the muscular cylinder itself, the nerves Fig. 99. — Perpendicular Section through one of Peyer's Patches in the lower part of the Ileum of the Sheep. — Teichniann. a, a, Lacteal vessels in the villi ; 6, 6, superficial layer of the lacteal vessels (rete angustum) ; c, c, deep layer of the lacteals (rete amplum) ; d, d, efferent vessels provided with valves ; e, LieberMihn's erlands ; /, Peyer's glands ; g, circular muscular layer of the wall of intestine ; h, longitudinal laver ; i, peritoneal layer. connecting through and through, the same as in the case of the villus, gland-structures and blood-vessels for produc- ing simultaneous action throughout, the principle being the same. Bur once within this system of reservoirs, it is easy to perceive that the force in the gut is available for compelling the lymph through the channels, and no power can prevent it but paralysis in the gut itself, as must appear obvious. In other words, every contraction of the muscular cylinder by 258 MUSCULAR FOKCE FOR THE LYMPH. compressing the air and aliment firmly against the mucous membrane and submucosa, in which the lymph-vessels and reservoirs are situated, thence against the resistent muscular cylinder, whence there is no escape, should have the effect of constringing the organs, closing upon them like the hand for the purpose . Please look at the anatomy well. No mechanics in the body exceeds it for simplicity and effectiveness. It is a work of the gods. By the action in the gut, then, and the action in the lymph-vessels and reservoirs, which are coordinated with the muscular cylinder, it is passed by the efferent vessels (d, d) through the gut, thence through the vessels to the glands in the mesentery, by means of rhythmical expansions and contrac- tions in the vessels, the same as in the systemic lymph-vessels, and which would' include the action in the glands, and there- fore need not detain us. Finally, to this we must add the force in the walls of the abdomen and the pumping action in respi- ration, the same as in the venous system, into which it empties, for producing simultaneous action and correspondence in the currents, which the scheme calls for, the same mechanics apply- ing to both alike. In order to definitely ascertain this circum- stance, also, I performed the same experiment as in the case of the portal blood and liver circulation, taking the body apart in the same way, carefully ligating the vessels before dividing them ; also the vena cava and oesophagus. And everything being ready, the thoracic duct was snipped, when the lymph spurted out with force to some feet distant ; and not waiting for the vessels to empty themselves ; I bore down upon the diaphragm with my open hand in imitation of inspiration, and every time I did this, the stream rose instantaneously into a jet the same as the venous blood had done. So, then, there can be no earthly doubt that inspiration pumps the lymph and venous blood simultaneously into the chest-cavity and lungs, the amount being determined by the energy and depth of inspiration and the fullness of the vessels. The following beautiful diagram of the lymphatic system (Fig. 100), by Pro- fessor Dal ton, will serve for impressing the matter. The lacteal system, spread out in the vast mucous surface, acted upon by the muscular cylinder and the muscles in the lymph- channels, this supplemented by the force in the walls of the THE FORCE IIST THE ABDOMEN. 259 abdomenfor compressingthegut, mesenteric vessels, and glands during inspiration, lifts the lymph to the lungs the same as the portal and hepatic blood and the blood in the lower cava sys- tem, and simultaneous with them. Please look at it. I do Pig. 100. — Diagrammatic Representation of the Lymphatic System. — Dalton. not see necessity for adding another word, the matter being so very obvious. In conclusion : That there is automatism in the lymph ves- sels is not only logically true, but the fact is scientifically ascertained. Notably, in batrachia four lymph-hearts pre- sent, one behind each femoral joint, for pumping the lymph 260 PROOF OF AUTOMATISM. coming from the hinder portions of the body into the ischiadic veins, and one in front of each scapula for pumping the lymph from the anterior portions into the jugular veins, the organs expanding and contracting regularly and rhythmically from fifty to sixty times per minute. Moreover, they are not syn- chronous with the action in the heart or with respiration, or even with one another, possessing independent action. ' k In the large ceratoplirys cornuta two pairs of ischiadic lymph-hearts have been found. In the tortoise the pelvic lymph-hearts are two, of a more circumscribed, rounded form, situated on each side of the bodies of the vertebrae, between the femoral joints and the hind-border of the carapace ; the valves at the inlets and outlets of the lymph-conduits, impressing the course of motion of the fluid, are here readily seen." ' ' In Lizards and Crocodiles the pelvic lymph-hearts are situ- ated near or upon the diapophyses of the first caudal vertebra. In Pseudopus P alias ii they lie between the muscles ivpon the sacral diapophyses, receiving the lymph each by a single con- duit from the great abdominal sinus, and transmitting it to the umbilical veins ; they pulsate about fifty times in tlie minute. In true serpents (Python, e. r/.)the lymph-hearts are elongate, and situated behind the last pair of ribs and upon the rib-like diapophyses of the anterior caudal vertebrae ; they receive the lymph by three orifices at one end, and transmit it by two opposite orifices to conduits communicating with the caudal vein. The three tunics of these hearts, of which the middle one is muscular, with the inferent and afferent valvular -v' ' ruetures, are well displayed in python" (Owen).* Italics are added. The following from Hermann possesses renewed interest : "In amphibia and certain birds (ratitse), the movement of the lymph is assisted by the rhythmical pulsation of lymph-hearts, of which four exist in the frog, two in other amphibia, and one in the ostrich. The central nervous organ connected with this rhythmical motion is said by some to be in the spinal cord, and by others in the hearts themselves. In guinea-pigs a rhythmical contraction has recently been observed (A. Hel- * Comparative Anatomy and Physiology of Vertebrates, vol. I., pp. 459-460. PEOOF OF AUTOMATISM. 26 J ler) in the lymphatics of the mesentery. As this proceeds along those portions of the vessel between the valves with a regular progression toward the larger trunks, it must be re- garded as a species of cardiac mechanism. "In the frog, the rhythmical movement of the lymph-heart seems to be dependent upon the integrity of spinal centres (Volkmann), one situated opposite the third vertebra for the anterior pair, and one opposite the sixth vertebra for the pos- terior pair. It is, however, affirmed (Eckhard, Schiif, Goltz, "Waldeyer) that the power of regular movement may some- times be recovered after it has been abolished by dividing the spinal nerves, supplying the hearts, or by destroying the spinal cord. " The lymph-hearts are. further, constantly inhibited from the optic lobes (Suslowa), this inhibition being controlled by centripetal stimuli, proceeding from skin or intestines (Goltz) " The following is from Gegenbaur :* " The lynrphatic trunks of birds have the same characters, but in them both the large trunk in front of the aorta (thoracic duct) and the small vessels are more independent. As in the reptilia, the thoracic duct opens into the superior vense cavae (vense brachiocephalicse). At the commencement of the tail the lymphatic system is also connected with the ischiadic veins, or with the afferent renals, in which point they resemble the amphibia and reptilia. In the mammalia, the walls of the lymphatic system are still more differentiated, although it often happens that in them also the sheath of the arteries bounds the course of part of the lymphatic current. Where they do not accompany the blood-vessels, they form frequent anastamoses, or wide-meshed plexuses, and are distinguished by valves, as are the same parts in birds. The lymphatic vessels of the hinder extremities, as well as the chyle-ducts, unite into a chief trunk in the abdomen, which is rarely paired, and the origin of which is frequently distinguished by a considerable enlargement (cisterna chyli). Thence they are continued into a thoracic duct, which opens into the commencement of the left brachio-cephalic vein ; the trunks * Elements of Comparative Anatomy, p. 595. 262 PROOF OF AUTOMATISM. of the lymphatics of the anterior parts of the body (of the head and anterior extremities), and of the wall of the thorax, open into and on either side of the same vein." Italics are added. Thus, with progress in development the lymph-hearts disappear, but in lieu of them we have increasing differentiation in this system of vessels, which become more and more muscu- lar ; and in place of the local dilatations forming the so-called lymph-hearts, which contain three coats, the middle one muscular, in the warm-blooded animals the muscular coat extends over the entire walls of the vessels, the same as in the veins with which they are homologous, only that the valves are greatly increased in number and the external fibrous tunic is thicker and firmer, which more than compensates for the k' hearts" by greatly increasing the force in the vessels which it effects. At the same time, it is seen that automatism is maintained, and must be so in the very nature of things. CHAPTER XII. NERVES TO THE VISCERA IN THE ABDOMEN, AID MODE OF CONNECTING THEM WITH THE CEREBRO-SPIiNAL AXIS. The Double Ganglionic Dorsal Chain in Vertebrates the Analogue of the Double Ganglionic Chain in the "Worms — Nerves of Meissner — Nerves of Auerbach — Mode of Connecting them with the Solar Plexus and Central Nervous System — Relations of the Nerves of Meissner and Auerbach with the Intestinal Mucous Membrane and Epithelium — Mode of Controlling the Blood-Supply from the Aorta-Trunk by Means of the Coeliac Axis, Superior and Inferior Mesenteric Arteries and then' Branches, so that Every Organ and Fractional Portion of the same can Regulate their own Sup- plies in the Measure of the Functional Activities — Connection of the Pneuniogastric Nerves with the Solar Plexus — Mode of Connecting the Solar Plexus and Spinal Ganglia with the Dorsal Nerves and Spinal Medulla, the Nerves of the Ganglionic Chain running up Both Roots of the Spinal Nerves to reach the Spinal Medulla — Every Nervous Ganglion a Centre of Nervous Force, Possessing both Sets of Fibres, or Dilator and Contractor Nerves — The Manner Reflex Action is Produced in the Spinal Cord and Medulla Oblongata through Sensory Impressions in the Mucous Membrane and Cutaneous Surface, for Expanding and Contracting the Vessels and Maintaining a Balance in the Circulation — Relative Amount of Nervous Force sent to the Viscera through the Pneumogastric and Splanchnic Nerves, Illus- trated by a Case of Fracture of the Fourth and Fifth Cervical Vertebras, Producing Displacement, with Laceration and Compression of the Spinal Cord — Effects from. Division of the Pneumogastric Nerves in the Neck, upon the Lungs, Stomach and Intestines — Death by Thirst and Starvation, Precipitated by Pulmonary Congestion from Paresis in the Capillary Network — The Action in the Kidneys, and the Rela- tions they Sustain to the Solar Plexus and Spinal Axis through Intercom muni eating Nerves — Ditto Ureters and Urinary Bladder. It will now be necessary to briefly refer to the nervons ap- paratus for producing the movements in the intestines, and for coordinating them with respiration, which, of course, would include the glandular appendages with the portal and lacteal systems for producing correspondence throughout, which the scheme calls for. Separate action in the alimentary canal is well enough for maintaining automatism in connec- tion with the special functions in the organs ; but since the whole relates to the cell-brood in the tissues, it is manifest that this involves correlation of the nervous forces with the federal centre for the organism for compelling response to the 264 CORRELATION OF NERVOUS FORCE. wants in the cell-brood, which is effected by means of the double rows of spinal ganglia and pneumogastric nerves which converge in the solar plexus, the common nervous centre for the viscera, so that the whole performs as but a single organ, only, under the action of the nervous forces radiating from the medulla oblongata and respiratory centre, in harmonious con- cert with the action in the lungs, with which everything is co- ordinated, to the end that a balance may be maintained in the organism; otherwise impossible. Now, then, with reference to this double ganglionic chain extending the length of the spinal column, the analogue of the double ganglionic chain in the worms, as it were, a remnant of this, which the principle in the mechanics compels to be retained, the structures in the gut be- ing fundamentally the same as in the worms, as before re- marked. And the gut being folded upon itself in the central portions, in form of the mesentery, which the shortness of the animal compels, the ganglionic chain necessarily undergoes a similar folding, whereby the solar plexus is formed ; while con- tinuity with the basal cerebral ganglia is maintained in the man- ner as stated, or by means of the trisplanchnic and pneumogas- tric nerves ; the former being thickened and elongated links, re- sulting from the folding up of the chain, the latter an adap- tation to the changes in the intestines which are now detached from the muscular envelope, compelling this mode of nerve- distribution for effecting coordination with the containing wails, as has already been fully set forth. In this manner, then, we have the massing of the ganglia in the solar plexus readily accounted for, and which would include all the other arrangements that obtain respecting it, as we shall see further on. The spinal axis is an outgrowth of the basal cerebral gan- glia, and possessing separate reflex nervous centres connecting with the viscera, vascular system, and the voluntary motor apparatus, represented by the gray central portions, subserves important functions in the mechanics for maintaining the local actions and enabling ready coordination with the federal centre in the medulla oblongata. Commencing with the mucous surface, we have, then, the following separate lines of nervous ganglia, with the interven- ing nerves, for producing the local actions in the intestines CORRELATION OF NERVOUS FORCE. 265 and for connecting them with the central nervous system, namely : 1. The thick ganglionic layer of nervous ganglia in the sub mucosa, or nerves of Meissner (Fig. 107, 1), with the nerves running thence into the villi to connect with the epithe- lium (2), which includes the whole mucous surface, at the same time supplying the capillaries and muscularis mucosae. 2. Next to this ganglionic layer, or between the circular and longitudinal muscles, is the thick ganglionic layer of Auerbach (Fig. 107, 4), for supplying the muscular cylinder, at the same time giving off inter- communicating nerves (3) to the gan- glionic layer of Meissner, which also gives off inter-communi- cating nerves, whereby the muscular cylinder and the mucous membrane are fully coordinated, so that it all works together harmoniously — vascular apparatus, glandular apparatus and muscular cylinder, inclusive of the muscularis mucosse, and which includes the stomach as well, since the nervous arrange- ments are fundamentally the same in it. 3. Next to this ganglionic layer, but outside the gut and removed to a distance from it, we have the federal centre for the intestines in the great solar plexus (Fig. 109), with the nerves extending thence over the superior mesenteric artery (Fig. 108, 1, 2) to the intestines to connect with the other two layers (Fig. 107, 5, 5), whereby the whole intestinal apparatus, inclusive of the glandular appendages, is coordinated and force is increased in the gut ; the same remark applying to the stomach, the nerves extending to it and the glandular ap- pendages over the branches of the cceliac axis (Fig. 109, 4). 4. Finally, we have the solar plexus connected with the ' central nervous system by means of the sj)lanchnic and pneu- mogastric nerves (Fig. 109, 2, 3), as before remarked. In this manner, then, the whole is connected through and through with the cerebro-spinal axis for coordinating the viscera with respiration, and for increasing nervous force as occasion may require. It is comprehensive, but the continuity of relation effected by means of the nerves for producing the actions with respiration is easily seen and readily understood. In order to perfect the mental picture of the nervous appa- ratus, however, it will be necessary to enter a little more into the minutiae. While the two ganglionic layers in the walls of 266 NERVES TO THE COLUMNAR EPITHELIUM. the intestines are plain enough, and minutely described, unfor- tunately this cannot be said of the nerves to the villi and columnar epithelium, which are not yet definitely ascertained ; and we are compelled to have recourse to analogous structures •, notably, the columnar cells of the salivary glands, in order to fully complete the nervous connections that obtain in the intestines. According to the exhaustive researches of Pniiger, the columnar cells sustain the most intimate relations to the nerves, which blend with them and form, so to speak, the footstalk of the cells (Figs. 101, 102), the nuclei of the columnar cells being evolved, as it were, in the terminal extremity of the nerves (Fig. 103). The following extensive excerpt* will place the matter fully before the reader : ' ' When we see the axis cylinder and its fibrils to be directly continuous with the fibrils of the columnar cells, without any difference being perceptible between the axis cylinder and the fibrils of these cells, we may legitimately describe the nerve as extending to the point where it joins the substance of the body of the cell. That is the most natural explanation that can be given. This explanation, however, possesses the greatest sig- nificance in regard to the mode of development of the glandular epithelium, because it directly follows that the young nuclei originate in the axis cylinders, and that the gland cells, which at a later period seem to constitute a thickening of the axis cylinder, bud forth, as it were, from the nerves. This expla- nation renders it intelligible why the nuclei of the columnar cells are so indifferent during the multiplication of the epithe- lium. In opposition to this view, which I regard as the most probable, it may be urged that, in consequence of the intimate fusion of nerve substance and epithelium at the periphery, no sharp limit can be drawn, showing where the one ceases and the other begins ; and that, moreover, it is probable that imperceptibly fine processes are given off by the nucleus of the columnar epithelial cells, which become detached at an early period by fission. That the nuclei of the salivary cells have processes cannot, however, be regarded as forming a valid objection to my view, since the young nuclei may really be thickenings of the axis cylinder fibrils. The Salivary Glands. Strieker's Manual of Histology, p. 314. NERVES TO THE COLUMNAR EPITHELIUM. 267 "I may further adduce, as a weighty argument in favor of my view, that the fibrils of the axis cylinder do not terminate at the surface of the fully developed salivary cells, but, as in the case of the ganglion cells, may be traced into their very substance. "Now, since the finest axis cylinders and fibrils extend to the columnar epithelial cells, and are connected with the processes Pig. 101.— Termination of Medullated Fibres Treated with Perosmic Acid in Isolated Salivary Cells. A, thick branched fibres distributed to large salivary cells ; B, fine nerves distributed to smaller salivary cells. From the submaxillary gland of the Rabbit. Magnified 590 diameters. — Pfiiiger. Fig. 102.— A, B, multipolar cells in connection with salivary cells. Magnified, A 480, B 500 diameters. C, peculiar cells with round thick processes, and containing refractile fat particles. Magnified 590 diameters.— Pfiiiger. that are in course of development, and since portions of these processes subsequently become large salivary cells, connected with thick medullated nerve fibres, it follows that the nerves must increase coincidently with the young epithelium to which they belong. Among these metamorphoses there also occurs a mode of termination of the medullated nerves, to which I some time ago called attention, and which consists in the nerve 268 NEKVES TO THE COLUMNAR EPITHELIUM. suddenly undergoing frequent division, then enlarging, and containing finely granular protoplasm, with many nuclei of various sizes. I have named this mode of nerve termination, that by a 'protoplasmic foot.' If, as I have sometimes ob- served, many of the nuclei appear to be provided with fibres, which can be followed into the interior of the nerve fibres, it is highly suggestive of the development of the gland cells from the nerves. "In regard to every explanation, it must be observed that transitional forms may occur, respecting which it is impossible to say whether they are epithelial or nervous. The continu- ous and luxuriant neoplastic formation taking place in the substance of the salivary ducts presupposes their regenera- tion, respecting which I have formed my own opinion, but have arrived at no definite conclusion. In like manner the persistent neoplastic formation of the alveoli in adult animals determines an atrophic detachment of those already present In moles I have sometimes found the alveoli with pale off- shoots of various forms, and pale finely granular contents, which may be such atrophied and separated alveolar seg- ments. " I first comprehended the complexity of all forms of salivary glands when I recognized the constant production and disinte- gration taking place in them, which is referable to the nerve substance." This genesis of the columnar cells in nerve- extremities may be seen in the different stages of cell growth in the follow- ing cut (Fig. 103, a, b, c, d, e), beginning with the nuclei and progressing till the cell is perfected {E) Accordingly, I have ventured to connect the columnar cells of the villi with the nerves proceeding from the ganglionic layer of Meissner (Fig. 107, 1) to the villi (2) This portion of the picture, there- fore, is ideal. But considering the energy in the absorptive processes and the rapidity with which the cells expand, and especially the quick response to stimulus I deemed myself justified in doing so. Not that a nerve fibre proceeds to each individual cell in the manner as given, for several may connect with a nerve (Fig. 103, M), but that they promptly propagate sensory impressions produced by the food, for setting up the SERVES TO THE COLUMNAR EPITHELIUM. 269 reflex actions in the ganglia for producing the movements in the muscular cylinder, inclusive, of course, of the blood-capillaries. For example, as soon as food is introduced into the stomach Fig. 103. — A, B, C, D, E, isolated cylindrical cells with processes containing nuclei ; A, B, D, E, magnified 590 diameters ; C, magnified 1,200 diameters ; F, G, H, cylindrical cells with processes, which are evidently young cells, and form atffa beautiful mosaic. Magnified 1,100 diameters. — Pfluger. Fig. 104. — A Gland from the Submucosa of the Small Intestine of a Suckling, ten days old. a, Ganglion ; b, nervous twigs given off by the latter ; c, injected capillary network. This preparation had been macerated for a very long period in pyrolig- neous acid. — Frey. or mechanical irritation applied to the mucous membrane — e. g., touching with a glass rod — the capillaries expand and the movements in the walls begin, which would seem to show intimate nervous connections subsisting between the epithelium. 270 NERVES TO THE INTESTINES. and the ganglionic layers, the same applying, of course, for the whole of the alimentary canal, while the investigations of Pfluger would show a reason for it. The following illus- tration (Fig. 104) exhibits the appearance of a ganglion (a) from the submucosa or Meissner's layer, with the nerves radiating from it (&). The following illustration (Fig. 105) is a section of the ganglionic layer between the circular and longi- tudinal muscles, by Auerbach, and named after him. Fig. 106 is a similar section by Klein,* in which the nerves are differ- ently treated and more highly magnified. Then, again, looking to the blood vessels and nerves, with reference to the local actions, wTe can readily understand how the vascular supply may be increased or diminished in a given viscus, or in a portion of the same, without interfering with neighboring organs or adjacent parts, and so as to limit the action to the special work in hand, in the measure of the re- quirements, which division in labor necessarily involves, as the whole is founded in individualism or automatism in the organs, as before remarked. Thus, in the case of the stomach (Fig. 110), the blood is supplied from the coeliac axis, which is embraced by the solar plexus (Fig. 109) ; hence the sensory impressions in the gastric mucous membrane produced by the food are reflected to the appellate ganglionic centres over the vessels when these are expanded correspondingly, the pressure in the arterial system causing them to be filled instantaneously. And any portion of the stomachal mucous surface may be flushed in order to increase the action in the part, whether in the car- diac or pyloric end of the organ, by expanding the local feeder, which is readily done. It is very pretty. The vessel to the great cut de sac, which gives off the feeder to the spleen, the separate ones to the mid-regions or central por- tions and pyloric end of the organ (Fig. 110) and the hepatic, all springing out of the coeliac axis with the great semilunar ganglia of the solar plexus at its root for compelling response to local demands, with the separate ganglia along the indi- vidual vessels for reporting the demands and enlarging the lumen of the vessel. The great anastomosis of the vessels * Hand-Book for the Physiological Laboratory.— Burdon-Sanderson. NEBVES TO THE INTESTINES. 271 Fig. 105. -From the Small Intestine of a Guinea-Pig. — Auerbach. a, Nervous inter- lacement : 6, ganglia ; c, lymphatic vessels ; d, lymphatics. Fig. 106. — Auerbach's Plexus of Small Intestine of Human Foetus, colored with gold. The plexus consists of fibrillated substance, and is made up of trabecular of various thicknesses, which unite in large placoids. Nucleus-like elements (unformed gan- glion cells) and ganglion cells are embedded in the plexus, the whole of which is inclosed in a nucleated sheath. (Oc, 2 ; obj., 7.) — Klein. 272 NEBVJiS TO THE INTESTINES. A r $ Fig. 107.— Nerves to the Intestines— partly ideal. 1, Ganglionic layer of Meissner ; 3, nerves from the same to the villi and columnar epithelium ; 3, nerves connecting same with the ganglionic layer of Auerbach ; 4, ganglionic layer of Auerbach ; 5, 5, 5, nerves connecting the intestinal apparatus with the solar plexus. A, A, villi ; B, summit of a lymphoid follicle ; d, muscularis mucosae ; E, circular muscles ; /, longi- tudinal muscles ; g, peritoneum ; v, v, arterial capillaries; h, submucosa. NERVES TO THE INTESTIXES. ^73 along the greater curvature provides against obstruction, should this occur in either the hepatic or splenic branches, so that compensation is readily effected by commensurate expansion in the other. In this manner, then, afflux of arte- Pig. 108. — Nerves of the Mesentery (reduced). — Bougery, etc. 1, Root of superior mesenteric artery and nervous plexus (a portion of the transverse colon is excised, in order to show this circumstance) ; 2, superior mesenteric plexus ; 5, 5, continua- tion of same over the walls of the vessels to the intestines ; A, intestines ; B, caecum ; C, appendix vermiformis ; D, ascending colon ; E, transverse colon ; F, descending colon. 274 NEliVES TO THE INTESTINES. Fig. 109. — Solar Plexus (reduced). — Bougery, etc. The letters of reference added. A, great right semilunar ganglion ; B, left ditto ; C, D, gaDglia connecting right pneu- mogastric nerve (2) and great splanchnic (3) nerve with the ganglion of the superior mesenteric plexus (E. 5) ; F, ganglion connecting right pneumogastric and great splanchnic nerves (2. 3) with the renal (G) and aortic ganglia (H) ; 4, coeliac axis, showing intimate blending of the right pneumogastric nerve ; 5, superior mesenteric artery and plexus ; 6, 7, 8, lesser splanchnic nerve, terminating in renal plexus : 9, renal artery and plexus ; 10, diaphragmatic plexus and artery ; 11, spermatic artery and plexus ; 12, tendon of small psoas muscle ; 13, eleventh rib ; 15, eleventh dorsal vertebra ; 16, crura of diaphragm ; 17, ligamentum arcuatum internum, the fibres irregularly divided. ARTERIAL FEEDERS TO THE STOMACH. 275 rial blood is compelled to be in correspondence with, the local actions in digestion. And looking from this to the small and large intestines, in which the action begins later on, it is readily perceived that there is extension of the Pig. 110. — The Cceliac Axis and its Branches, the Stomach having been raised, and the Transverse Mesocolon Removed. — Gray. same principle in mechanics to them also. For example, the small intestines are supplied by the superior mesenteric artery (Pig. Ill), which functions as the feeder to these por- tions, the vessel giving off lateral branches to feed the vari- ous portions, the vessels being given off at regular intervals, 276 ARTERIAL Fl.EDERS TO SMALL INTESTINES. commencing with the duodenum. The transverse and ascend- ing portions of the colon and ccecum are supplied by the colica media (11), colica dextra (14), and ilio-colica (15), given off from the opposite side of the vessel ; while the descending colon and rectum are supplied by the inferior mesenteric artery (Fig. 112, 9), the superior hemorrhoidal ( 1 3) descending as low as the middle of the sacrum, where it divides into two Fig. 111. — Course and Distribution of the Superior Mesenteric Artery. — Wilson and Bu- chanan. 1, Descending portion of the duodenum; 2, transverse portion; 3, pancreas; 4, jejunum ; 5, ileum ; 6, caecum and appendix vermif ormis ; 7, ascending colon ; 8, transverse colon ; 9, descending colon ; 10, superior mesenteric artery ; 11, colica media ; 19, the branch which inosculates with the colica sinistra ; 13, pancreatico- duodenalis inferior ; 14, colica dextra ; 15, ileo-colica ; 16, 16, vasa intestini tenuis. branches, which continue along the sides of the rectum, divid- ing up into still smaller branches, to be distributed between the mucous membrane and the muscles, nearly to the anus, anas- tomosing with the middle and inferior hemorrhoidal branches of the internal iliac and internal pudic arteries. By means of this arrangement, then, together with the local ganglia and nerves for operating them, the vessels are readily expanded and contracted for regulating the blood-supply. One other ARTERIAL FEEDERS TO LAHGE INTESTINES. 277 thing ! Bear in mind that every nervous ganglion is a dilator and contractor centre for the vessels ; hence, it is readily per- ceived that the actions can be carried on in the several portions independently, and without involving other portions. For example, expansion in the lateral branches to the ascending and Pig. 112. — Branches of the Inferior Mesenteric Artery. — Wilson and Buchanan. 1, 1, The superior mesenteric, and small intestines turned over to the right side ; 2, caecum and appendix caeci ; 3, ascending colon ; 4, transverse colon raised upwards ; 5, descending colon , 6, sigmoid flexure ; 7, rectum ; 8, aorta ; 9, inferior mesenteric artery ; 10, colica sinistra, inosculating with, 11, colica media ; 12, 12, sigmoid branches ; 13, superior hemorrhoidal artery ; 14, pancreas ; 15, descending portion of the duodenum. transverse colon (Fig. Ill, 12, 14, 15) should not affect the vas- cular supply to the small intestines, the vessels remaining at a given calibre, since pressure in the arterial system would compel them all to be filled simultaneously But, since the actions alternate, it is easy to perceive how one set of vessels may contract their calibre as others expand; which 278 VASO-DILA'IOR AND CONTKACTOR NERVES. must be done in order to obviate too great depletion of the arterial system ; otherwise inevitable. So that this also has its metes and bounds for maintaining a balance in the organ- ism. During full digestion a vast amount of arterial blood is thus poured into the organs ; so that the arterial system is com- pelled to condense itself in order to maintain pressure, tending to produce brain-ansemia ; hence the heavy sleep of the glutton, which is especially well marked in cases in which a degree of anaemia exists — e. g., convalescence from essential fevers and wasting diseases. For this reason, also, it acts beneficially in cases of cerebral irritation by calling off the blood, thereby inducing sleep. In the lower animals, in which arterial pres- sure is low, it induces a semi-comatose condition for many days together, since digestion is slow iu them. But in the warm-blooded animals provision is made for digestion during the maintenance of the activities, but which requires that arterial pressure should be maintained, since it is by means of this that the local actions are increased, while resented in the figure) connect with the solar plexus by means of the splanchnic nerves (extended links indicating where the gang- lia belong in the chain in the respective sides) ; below, they connect with the aorta and lower cava, following the branches into the viscera, increasing in numbers as we approach the pelvic viscera, the occasion for which will appear later on ; above, with the viscera and vessels in the chest, and blending with the pneumogastric and phrenic nerves in the solar plexus. In this manner, then, the whole is consolidated, and the action in the viscera is unified with the central nervous system, so that a balance is readily maintained in the circulation during respiration and the voluntary movements, etc. In other words, the parts are unified through the nervous apparatus. The question as to which of the two lines of nerv- ous force from the central nervous system to the stomach and intestines — this by way of the pneumogastric nerves or that of the splanchnics — is the more important, would seem to be in favor of the former, judging from the evidence before us and our own observations ; though, perhaps, a true comparison cannot be made for the reason that the two sets of fibres, or dilators and contractors, are not equally distributed between them, the pneumogastrics containing more of the former, the splanchnics more of the latter fibres ; while the one relates more particularly to the action in the muscular cylinder, the other the vascular apparatus ; while neither are exclusive in their functions. But strong currents of nervous force set in and out of the viscera to and from the central nervous system through the pneumo- gastric nerves, for producing correspondence between them and the containing walls, at the same time increasing the actions in the muscular cylinder and vascular apparatus, ex- panding the network of capillaries and producing peristalsis ; since stimulation of the pneumogastric nerves produces these effects, while stimnlntion of the splanchnic nerves produces ACTION IN 'IHE J'NJiUMOGASTKlCS. 237 contraction of the capillary network, though it also produces peristalsis ; but they cannot effect the actions in the stomach nor set up the movements in the medulla oblongata during ingestion for bringing the containing walls into correspondence with the exrjansile action in the siomach for producing the requisite room for the food and maintaining a balance in pressure, otherwise impossible ; at the same time expanding the capillary network in the gastric mucous membrane for increasing the digestive and absorptive processes in the organ. It comes to this in the main : that the pneumogastric nerves produce expansile action in the viscera, while the splanchnics have the opposite effect— producing contraction, especially in the vessels. And when the pneumogastrics are divided in the neck, the stomach and abdomen can no longer be expanded nor any food be taken, the animals dying from thirst and starvation, precipitated by pulmonary congestions from two to five days, the nerves not uniting, which has occasionally hap- pened ; while the respiratory rhythms fall from twenty-five to thirty per minute in the dog to seven and eight, sometimes as low as two per minute. But important corroborative evi- dence is obtained also at the bedside in cases of spinal injury, in which the nervous currents through the spinal cord are cut off, thus throwing the burden of effecting coordination in the stom- ach upon the pneumogastrics, and showing the great role they perform in the mechanics in the abdomen, as well as in the chest, in connection with respiration and circulation, which has already been fully considered. Thus, in a case of spinal injury which came within my own knowledge, in which the fourth and fifth cervical vertebrae were fractured and displaced so as to crush the cord, producing complete paralysis, with anaesthesia from the clavicles down, a little sensation only being perceptible about the clavicles, not knowing, indeed, "which portion of the body was in contact with the bed but by actual sight," as he said, commenting upon it, and deeming it very curious, the patient living, however, over twenty days, the following facts were ascertained ; notably : 1 . Respiration was diaphragmatic and labored, shallow, and from 25 to 30 per minute ; pulse, 120 to 130 per minute ; polyuria, with complete paralysis of the bladder, the urine having to be drawn every 283 NERVES TO VESSELS AND VISCEBA IN ABDOMEN. /hur T.'DtrjalNenit Tha Z'.'E'iinlAttur /ToatSf'IltrinlM pom I'/Sntm/Mnir Jl-Mm Z7*Saertithh-ur rnnrt^Sarml Af/rv, fres>S$£nriH. It-em (oectjfftft Yrm Oii^glnvftAaGinUiAiTehtU Fig. 116.— The Abdominal Sympathetic Nerves in Diagram.— Flower. EXTENSIVE DISTRIBUTION OF THE PNEUMOGASTRICS. 239 three or four hours, the patient being made aware of the pass- ing of the instrument by sight only ; tendency to diarrhoea, but no sensation about the anus, the patient cognizant, how- ever, when an action of the bowels was expected, directing the attendant to the circumstance ; and when the bed-pan was placed under him, presently there would be an action. Occa- sionally he relished food ; there was considerable venous stasis in the systemic capillaries, with tendency to serous effusions in the connective tissue, the result rather of defective absorption. He lingered twenty-one days, and the post-mortem examination showed the nature of the injury to the spinal cord, which was crushed and completely disorganized at the seat of injury. JN'ow, then, attention is specially directed to the interesting oircumstances italicized in the notes — namely, the polyuria and the sensory impressions transmitted from the colon during a faecal action. Of course, the polyuria, with the tendency to diarrhoea, should be explicable, since they flow out of the mechanics as a result of the lesion in the spinal cord, and are easily explained. The spinal cord being crushed, this cuts off the nervous force from above through the splanchnic nerves, so that the cervical chain and cardiac plexus must be the route of the nervous supply ; this, together with the contractor fibres in the pneumogastric nerves, which is not sufficient for maintaining the lumen and tonus in the vessels ; in consequence, an amount of dilatation results, producing unusual fullness in the vessels and hy- peremia in the organs ; hence, the polyuria and the tendency to diarrhoea. Then, again, the embarrassed respiration also t^nds to produce fullness in the portal vessels and lower cava system, which should increase the secretory actions, so that it is not at all difficult to account for the polyuria and tendency to diarrhoea, under the circumstances. The consciousness of the faecal action is undoubtedly produced through the pneu- mogastric nerves. The contiguity of the transverse colon to the stomach suggests direct extension of the nerves to the colon, the left pneumogastric nerve especially, which is dis- tributed principally over the anterior poriions of the stomach ; but in order to do this, the nerves would have to penetrate both layers of peritoneum, gastric and colonic ; besides, it 290 EXTENSIVE DISTRIJHTION OF THK PNEUMOGASTRICS. ' would interfere with the free action of the organs. The nerv- ous force, then, passes through the solar plexus, thence up the colonic ligament, colica-media, colica-dextra, colica-sini tra, and inferior mesenteric arteries to the colon ; showing, also, that the current is not broken at the ganglia, but passes to and fro between the viscera and central nervous system without let or hindrance. The pain in colic from over-distension of the colon by the gases, and the traction upon the nervous filaments which this produces, has similar explanation ; the sensory im- pressions being propagated over the pneumogastric nerves, and so promptly reaching the brain And the lungs become filled up and carnified after division of the pneumogastric nerves, for the reason that the fibres from the posterior pulmonic and cardiac plexuses are not sufficient for maintaining the normal lumen in the capillary network in the alveoli with the pneu- mogastric fibres divided, the vessels consequently become en- gorged, leading to effusions and haemorrhage ; hence this cir- cumstance. According to Latschenberger and Deahna,* the vagus (pneumogastric) contains both pressor and depressor (vaso-contractor and vaso-dilator) fibres ; consequently, we should have congestions in the vessels of the chest and abdo- men after division in the neck ; and the pulmonic congestions should therefore have this explanation : the flood-gates thrown open, we must have inundations in the lungs as well as in the abdomen flowing out of this circumstance, to the contrary, notwithstanding. At any rate, it would explain the pulmonic congestions and the other wrould not, which places it under a cloud. The thick bundles of nerve fibres, continued from the pneumogastric nerves to the central ganglia of the solar plexus (Fig. 109, 2, (7, D, E), are reflected thence over the cceliac axis (4, 4) to the stomach, liver, spleen and pancreas ; and over the mesenteric artery (5) to the small and large in- testines, the cffical and sigmoid portions, by way of the inferior mesenteric artery ; while that by the splanchnic nerves (3, H) passes by way of the semilunar (A, B) and central ganglia Concerning the Action in the Kidneys. — Now, then, let us * Latschenberger u. Deahna, PfliXgefs Arehiv, vol. xiii., p. 22. PHYSIOLOGICAL ANATOMY OF THE KIDNEYS. 291 look from the mechanics in the intestines to the action in the kidneys for interpreting the special phenomena, anatomical and physiological, appertaining to them also. Briefly, the renal artery (which is a very large vessel), previous to entering the kidney, divides np into four or five branches that pass into the organ at the hilus — the vein in front, the ureter behind ; and after dividing and subdividing to form the arterioles rectce between the tubili recti, send off lateral branches (Fig. 117, ai, va), which terminate in the capillary tufts inclosed in the expanded ends of the convoluted tubes known as corpora Malpighiana {gl) ; and from which proceeds an efferent vessel (?>c), which also breaks up into a capillary network around the convoluted tube (c), and medullary substance, or very much as the portal vein in the liver, and winch again converge in a com- mon vein (v, z) that discharges into the interlobular vein, or vena recta, side by side with the arteriola recta (m). The convoluted tubes are composed of two layers, the mem- br ana propria and an epithelium, consisting of a single layer of polygonal nucleated cells, in which metamorphosis is effected. The epithelium occupies about two-thirds the diam- eter of the tube, the remainder representing the lumen ; but that within the glomerulus itself is thinner. Finally, these convo- luted tubes lying in the cortical portion are gathered up into the straight bundles that form the conical masses known as the pyramids of Malpighi (Fig. 118, 3), coalescing and joining at acute angles at the bases and within the pyramids to bring about this result, each one containing from two to five hundred tubes, which open upon the apices (4) of the pyramids (from eight to fifteen in number), that project into the calices and pelvis of the kidney. Now, then, the effect of this arrangement is, when the lumen of the renal artery is enlarged for increasing the action in the organ, it first flushes the capillary tufts in the glomeruli (Fig. 117, va, gl), extending thence to the vascular plexuses of the convoluted tubes (ve, c) ; but as the tufts are the proximal portions, of course arterial pressure should be more effective here, tending to strain out the substances that pass easily through the animal membranes, passing out with the stream of water in which they are suspended, or down the tubes, washing 292 PHYSIOLOGICAL ANATOMY OF TIIK KIDNEYS. out the secretions as it goes along; while the remainder, which is under reduced pressure by reason of this depletion, passes out through the efferent vessel to the capillary network of Fig. 117.— Course of the Blood-Vessels within the Cortex Proper (diagrammatic), m, The space occupied by the medullary radius ; b, that occupied by the convoluted canals ; ai, arteria inter-lobularis ; vi, vena iuter-lobularis ; va, vas afferens glome- ruli ; ve, vas efferens glomeruli ; gl, glomerulus ; vz, venous twig of the inter-lobular vein. — Ludwig. Fig. 118.— Section of the Kidney, surmounted by the Supra-Renal Capsule.— Wilson. 1, Supra -renal capsule : 2. vascular portion of the kidney ; 3, 3, tubular portion, con- sisting of cones ; 4, 4, papilla projecting in the caliches ; 5, 5, 5, infundibula ; 6, pelvis ; 7, ureter. the tubes, the slower circulation in them affording opportu- nity for effecting metamorphosis in the epithelium, as in the case of the portal circulation, to which it sustains close resem- THE ACTION IJST THE UEETEBS AND BLADDER. 293 hlance in more respects than one, since the rhythmical com- pression of the liver-substance during respiration for increas- ing the venous circulation in the liver, should have the same effect upon the venous circulation in the kidneys, for the principle is precisely the same The gentle and uniform com- pression of the kidneys during inspiration must certainly compel the blood into the renal veins, while the suction force in the chest should pull it toward the lungs — the same as the portal blood, and the blood in the hepatic veins. Of course, the same mechanics also applies for the secretions, tending to force them out into the pelvis of the kidney (Fig. 118, 6). But here we have to note a special arrangement that obtains for increasing the action, constituting the fine adjustment in this mechanics ; notably, the action in the pelvis and ureter. The ureter, which is expanded at the kidney to form the pelvis and infundibula (6, 5), is a muscular organ richly supplied with nerves from the renal plexus (Fig. 1(.;9, 9), while the special ganglion or mind-centre {G) directs the reflex actions ; and there is but little reason to doubt that by means of this systematic arrangement there is a pumping action going on in the pelvis of the kidney, much in the same manner as takes place in the expanded buccal cavity of the leech during imbi- bition for aspirating the blood in the capillaries, or the still more striking example furnished in the nursing infant aspi- rating the milk through the lacteal tubes, the papilla of the mammary gland bearing close resemblance to the renal papillae which project into the cavity of the pelvis for the purpose. So that, while the infant is aspirating the mammary gland, the ureters at the same time are aspirating the kid- neys. Is it fanciful % Answer this question, then : What is this mind-centre doing here, and what are muscles and nerves doing in the ureter, since they cannot be purposeless % Can it be doubted for a single moment, even, that they relate to the functions in the kidneys, designed to expedite them ? I think not. And wherever found, muscles and nerves perform .work in correspondence with the special physiological require- ments for which they are the relative adjustments, here as elsewhere. What matters it where they are located ? Work is their office, and work they do. Then, too, look at the shape 294 THE ACTION IN THE ETKETER8 AND BLADDKK. of the expanded portion of the ureter (Fig. 118, C), and com- pare the muscles with the muscles in the leech and oesophagus ; notably, the internal layer of circular and the external layer of longitudinal muscles, layer for layer, in them all, while each is operated by nerves from a special ganglionic nervous cen- tre, for producing and coordinating the actions, or the same as the pneumogastric nerves and ganglia in the case of the oesophagus, the special arrangements which obtain in them being adaptive changes to meet the requirements in the case. Keeping in mind, also, that the kidney, with the afferent and efferent vessels and discharging duct is an entity, or inde- pendent organ, therefore endowed with automatic action, which is essential for maintaining the life that is in it and carrying on its functions, otherwise impossible. And it is well to look over the organs in this way, for pressure is the basis of all of them, and must be so, in the very nature of things. Well, what does it all mean, if not to act alike in pumping the fluids into themselves in connection with the special functions, pressure applying to all alike % Nay, there is other evidence proving they mitst act alike ; otherwise, it would be utterly impossible to carry on the functions in the kidneys, since the uriniferous tubes would be choked from the accumulations in the pelvis from inability to effect expansion in the urinary bladder at the distal end of the ureters, which must expand in similar manner under the stimulus of the urine for receiving it. Thus the waves of expansion and contraction, passing along the ureters to the bladder, causes the bladder to expand, the waves losing them- selves in the general expansion which results in the bladder, or the same as in the stomach, when ingesta passes into it from the oesophagus, finally the same as in the worms, notably the leech (Fig. 16, 1, 2, 3), the structures being also homologous, the principle the same ; otherwise, it would be utterly impos- sible to introduce the urine into the bladder. Besides, the urinary bladder is rich in all the elements in arterial tissue ; namely, unstriped muscles, elastic and connective tissue fibres, the bundles running in every direction, and when contracted, as in the empty condition, the structure is very dense. And to think of straining it open, as when fully distended with Urine, by the THE ACTION IN THE URETERS AND BLADDEE. 295 action in the ureters and kidneys, thereby producing strain to the delicate tubuli recti and convoluted tubes extending back to the glomeruli, or through and through the organ from hilus to cortex, is nothing short of madness. The force is not there for expanding the bladder, "but upon the ground, where the work is done in the walls of the viscus itself, otherwise it were utterly impossible to introduce the urine into the bladder, or operate the kidneys. The strong muscular walls of the viscus are not forced into extension by the ureters and kidneys. Aeh Gott ! Never in tliat way, under the canopy of heaven ! Impossible ! Then, if you would not have the urine damming back upon the delicate renal structures, thereby arresting the functions in these organs, the ureters in common with the bladder must respond to the stimulus of the urine ; the same as the oesophagus and stomach, the cystic ducts and gall-bladder, under the action of the special stimulus in the organs, the structures being fundamentally the same, and pressure apply- ing alike to all of them. Then, again, as the bladder fills and expands with the urine, it rises into the cavity of the abdomen ; and when the con- tents are being discharged, it sinks again to the bottom of the pelvic basin. Accordingly, we have the longitudinal mus- cles increased in the ureters as the bladder is approached, and the addition of an internal layer, so that the tubes may readily elongate and contract under the action of the special nerves in the parts, which extend over and coordinate them so that correspondence is readily effected with the changing volume of the viscus ; otherwise, the ureters should be bent upon themselves during the filling, thereby interrupting the flow, while during expulsion they would be subject to terrific strain, painful even to contemplation. Finally, the to-and-fro movements in the kidneys themselves during respiration, from the action in the diaphragm, would also call for the longitudinal muscles in the ureters, the same as in the oesopha- gus, vena cava, etc. Hence these muscles. Displacement of the kidneys is obviated by the layer of peritoneum that covers and holds them against the pos- terior wall of the abdomen ; though occasionally we have "a 296 TIIE ACTION IN THK KIDNEYS. floating kidney," the organ seeming to slip about too freely in the general cavity, not being securely held by the overlying peritoneum and connective tissue, forming a kind- of mesenteric ligament to the organ, which also shows the necessity for the special anatomical dispositions in the artery, vein and ureter for effecting elongation and contraction during respira- tion, so as not to interrupt the functions in the organ. And looking at all these beautiful adjustments for special work, can it be doubted for a single moment that the arrangements which obtain in the pelvis of the kidney should not expedite the functions in these organs, whereby the whole is brought in correspondence ? Thus, in the expanded portion forming the buccal projection of the pelvis (Fig. 118, 6), the muscles are thick, but thin in the calices, and cease altogether at the papillae ; it follows that expansion in the muscles must inevi- tably exert a suction force upon the contents in the papillae and uriniferous tubes. It is all very wonderful ; but what more wonderful than Life itself ? And when undifferentiated proto- plasm locomotes from place to place — moreover, is highty sen- sitive— it looks still more wonderful. And if the ureters should do nothing more than elongate and shorten with respiration, and with the filling and. the emptying of the bladder, this of itself would exert a suction force upon the renal secretions ; but there is every reason for believing in a special action in the pelvis of the kidney. In order to account for the rapid appearance of substances in the urine, the old authors conceived that a short route ex- isted from the stomach to the kidneys. Well, there is a short and direct route — as direct as it can be made — but it is through the nervous channels that the thing is effected — namely, by the renal ganglion (Fig 10y, G), and the nerves and ganglia of the solar plexus, reflected thence over the coeliac axis (G. F, 4 ; G, C, 4) ; and since sensory impressions made upon the gastric mucous membrane would tend to enlarge the lumen of the renal arteries by reflex action, and thereby flush the glomeruli and increase the secretions in the organs correspondingly, we can readily understand the rapid reap- pearance of the substances in the urine, especially when we remember the mechanics in the stomach for compelling absorp- THE ACTION IIST THE KIDNEYS. 297 tion, and that the entire circuit of the blood is made within a minute. In this manner, then, we can readily understand the specific action of diuretics, which, by acting upon the nerves and ganglion of the renal plexus, expands the lumen of the arteries and increase the blood supply to the organs corre- spondingly. The rich nervous connections subsisting between the renal plexus and the splanchnic nerves (Fig. J 09, 9 ; G, A, b), the third splanchnic terminating in the plexus (7, S), will give some idea of the importance of the renal functions for main- taining a balance in the organism, since it is through these nerves that the lumen of the artery is regulated ; also, why ap- plications made to the skin surface in the lower dorsal and upper lumbar regions should be reflected thence upon the renal arteries for contracting the lumen in cases of engorgement or inflammatory processes in the organs. Look at it, please ; it is of great importance. The sensory impressions in the skin, where the applications are made, are transmitted over the rela- tive intercostals to the appellate reflex centre in the spinal cord, thence through the third splanchnic nerve (7, 8) to the renal plexus. Of course, force is also transmitted through the other splanchnic nerves, but the relations of the third splanchnic would indicate it to be the main channel. It is needless to extend the matter. CHAPTER XIII. ADJUSTMENTS IX THE WALLS OF THE ABDOMEN WITH RESPI- RATION AND THE FUNCTIONS IN THE PELVIC YISCEKA. Action in the Mesentery — Ad justments with Respiration and the Functions in the Pelvic Viscera— Adjustments -with Gravitation and the Erect Position— Formation of the Sacral Promontory in Man — Adjustments in the External Oblique Muscles — Ex- ternal Oblique Muscles and Diaphragm Antagonizing each other in Respiration — The Respiratory Plane upon which the Viscera Move in Respiration — Action in the Trausversalis — Action in the Internal Oblique ; the Relations it Sustains to the Pelvic Viscera — Mode of Coordinating the Muscles in the Abdomen with the Pelvic Viscera — How the Diaphragm Assists the Action— Os Sacrum and Sacro-Ischiadic Ligaments, the Floor of Support to the Pelvic Viscera, as also the Point of Resist- ance to the Detrusor Force in the Abdomen — Functions of the Levator Ani — Me- chanics in Eniesis — The Stomach Energetically Compressed by the Simultaneous Contraction of the Diaphragm and Muscles in the Abdomen, Compelling Rapid Re- gurgitation. Frequent reference has been made to the action of the mass of intestines known as kt the mesentery " (Fig. 119), in connec- tion with respiration and circulation ; transmitting the force in the walls of the abdomen upon the stomach, liver, portal and lower cava systems, spleen, pancreas, thoracic duct, and the glands of the mesentery for increasing the action in them all, and compelling the venous blood and lymph within the abdomen to flow into the chest-cavity simultaneously during inspiration, as has already been fully set forth ; and it remains to show the relations it also sustains to the viscera in the pel- vis for increasing the action in them, in the bladder daring urination, and in the colon and rectum during defecation, since the action in the walls of the abdomen is in concert with the action in the pelvic viscera ; for the parts are fully coordinated by means of the nerves extending into them from the cerebro-spinal axis, and it all performs as but a single organ only for expelling the waste products, while the reflex actions for producing it are propagated from sensory impres- sions in the mucous surface of the special viscus ; the same THE MESEXTERY. 299 mechanics also applying for the contents in the womb. This mass of intestines, occupying the mid -abdominal regions, is in a manner isolated by the ligament (Fig. 119, 3), the only points of connection being the duodenum above, where the je- junum (i) terminates, and the csecal pouch below, where the ileum ( . ) ends ; and by simply dividing the intestines at these two points, and the ligament (3) connecting it with the lumbar vertebrae, the mass is readily removed from the abdomen ; Eig 119.— The Mesentery. 1, 1, 1, Coils of jejunum : 8, 2, coils of ileum ; 3, ligament of mesentery. while the ligament itself may be spanned by the hand ; this, notwithstanding 15 to 20 feet of intestines in the man, 40 to 50 in the horse, and 5>U to 60 in the ox, are thus embraced by the ligament. Mlrdbile ! "Well, by reason of gravitation, the ligament in the quadruped (Fig. 25, If) is perpendicular, while in the erect position of the trunk, as in man (Fig. 120), the vis- cera gravitate against the lower abdominal walls (/, E) and the widely-expanded ilia, carrying the ligament with them, so that it now occupies an oblique position in the abdomen {M,E), gravi- tation compelling this circumstance. Of course, the weight in the colon (c), stomach (s), spleen, and liver (L) is also sustained bv BOO POSITION" OF 'I HE VISCERA IN THE ABDOMEN. the mesentery, but transmitted of necessity to the walls of the abdomen and pelvis as the common floor of support, since it would not do to have them sagging to the diaphragm or any strain to the ligaments ; otherwise inevitable. But one thing calls for another. Thus, for obviating the pressure in the pelvic Fig. 120. — Longitudinal Section of the Abdomen, showing position of the mesentery with the body erect, gravitating downward against the lower abdominal walls and false pelvis. M, center of mesentery ; J, /, cods of small intestine ; E, anterior wall of the abdomen ; B, bladder ; R, rectum ; C, colon ; S, stomach ; L, liver ; D, diaphragm ; P, pancreas ; Q, duodenum. viscera produced by the weight of the viscera, the pelvis is tilted backicard in man, so as to throw the mesentery against the lower abdominal walls (J/, E) and the expanded ilia, a few loose coils only lightly resting against the pelvic viscera {.R, B), whereby impact from the diaphragm during inspiration and from locomotion, otherwise inevitable, which would tend to force out the contents in the organs, subjecting them to FORMATION" OF THE SACEAL PROMONTORY. 301 strain as well, is avoided. It is simply wonderful. But there is an obvious reason for every one of the adjustments that obtain in man. Please think over it carefully. I can do no more to make it plainer. But to me, however, it seems suf- ficiently obvious. This backward tilting of the pelvis, produc- ing the sacral promontory in man, is the result of the erect position of the trunk and the reactionary forces in locomo- tion— gravitation, the propelling force for driving the body forward, together with impact in the acetabula transmitted, through the crural bones, making them the points of resist- ance, tending to carry the pelvis backward ; hence, the sacral promontory in man. It is deeply interesting, containing a number of features connected with the bones. It is needless to add that the great development of the pelvic bones in man has similar explanation, strain tending to fall here during locomo- tion from the weight in the body and viscera. * Before proceed- ing to the adjustments with the pelvic viscera, however, it will be necessary to first consider the adjustments with respiration, since this is fundamental in the organism ; when it will be in order to regard the pelvic arrangements, making it logical and. scientific, at the same time omitting nothing which a physio- logical treatise should do, taking in all the relative anatomy by showing the adaptations of means to ends, since the whole relates to special work for which they are the relative adjust- ments. Action in the External Obiiqui. — The external oblique muscles (one for either side), obliquus externus abdominis, is so called from the obliquity of the fibres which bisect the longitudinal axis in the body at an acute angle (Fig 121). It springs by eight fleshy digitations from the external surface of the eight inferior ribs, and sweeping boldly downward and inward embraces the entire abdomen in front and upon the sides, the dense fibrous leaflet, in which the muscular bundles terminate, sweeping over the powerful rectus abdominis (Fig. 121), indicated by the band of dark fibres (linese transversa) to inosculate with the fibres from the opposite side in the linea alba, whereby the anterior portions of the abdomen, where For full particulars, see work on "' Gravitation and Development." 302 ACTION IX TIIK I.XTEEXAL OBLIQL'E MUSCLES. strain tends to fall from the weight in the viscera, is greatly strengthened ; at the same time, this aponeurosis subserves important purposes in conjunction with the aponeuroses from the other muscles, in maintaining the rectus abdominis in posi- tion, forming a strong sheath for the powerful cable-like mus- Fig. 121. — Showing direction of the fibres of the external oblique muscle. — Gray. The letter A is added. cle extending from sternum to pubes, that it may not slip out of position in the rude experiences to which the animal is sub- ject ; also, tending to fly up from its bed with every contrac- tion in the muscle, especially when energetic, as when the body is being flexed. Below, the fibres are inserted into the anterior portion 01 the crest of the ilium and pubes, which assist the recti abdominis and internal obliqui in flexing the trunk at the ] umbar vertebrse in bending over or stooping. Now, TJ1E RESPIRATORY PLANE. 303 then, why should the fibres in the external muscular layer of the abdomen have this oblique direction, downward and inward, embracing the abdomen, since the matter has relation to special work which these muscles perform and are the relative adaptations? It is readily answered. When they contract, they pull the viscera upward and backward, the direction of the force being upon a plane extending from the umbilicus (a)* to the upper dorsal curvature (A), which is the respiratory plane, all the fibres running in this direction. Look at it well, please ; it will pay you, for the gods have left their mark. Well, when these muscles pull the mesentery with the adjacent viscera toward the deeper portions of the chest dur- ing expiration, the diaphragm expands, in order to admit of the movement, which produces high pressure in the lungs, while the insertions into the lower ribs have the effect of pulling them downward, whereby the action in the lungs is greatly increased, causing the air and blood to rush out of the alveoli with corre- sponding energy But when the action is reversed, this lets down the viscera again, since they must follow the floor of support, while the action in the diaphragm, by reason of the insertions into the ends of the seven lower ribs (Fig. 26) and lumbar vertebrae, and the manner it is ballooned in the chest-exca- vation, throws the viscera forward and downward (downward and backward in the horizontal position), pressing them against the anterior abdominal walls, while the ribs are thrown upward, flaring them open upon the sides, caused by the muscular fibres in the diaphragm (Fig. 27, F, F) pulling upon the cartilaginous ends of the ribs in the long axis (pp. 89-91) ; hence this circum- stance. This action produces low pressure in the chest, the lungs at the same time expanding for confining it to the alveoli ; whereby the air and blood are compelled into the chambers simultaneously. And by this alternating action in the diaphragm and muscles in the abdomen we have the pump- ing movements produced in respiration, the lungs, of course, acting in concert. In this manner, then, the respiratory plane obviates impact in the pelvic viscera during inspiration ; other- wise inevitable, as must appear obvious. * The terminal letter of " linea." 304 THE RESPIRATORY PLATSTE. The wide fibrous aponeurosis, spreading out like a sheet over the anterior portions of the abdomen, distributes force evenly over the viscera, so that undue pressure cannot fall upon any one of the organs, each one sustaining its relative amount of pressure according to extent of surface. And the great role the muscles perform in respiration has forcible illus- tration by simply placing the open hand upon the sides of the abdomen when talking, whistling or singing, the faintest vocal resonance being promptly reported by the movements in these muscles, while the action swells with the volume of the sound. There is no mistaking it. And there is nothing more perfect than the arrangements that obtain in this respect. The rounded lower border of the aponeurosis, known as Poupart's ligament, inserted into the spinous processes of the ilium and pubis, spans the femoral artery, vein, crural nerve, flexor muscles of the thigh (psoas and iliacus internus), like a ligamentum arcuatum in the diaphragm, while the powerful deep fascia of the thigh {fascia lata) inserted into it hold it iirmly, so that during contraction of the muscle strain cannot fall here. At the same time it gives protection to the vessels. Very pretty — all of it. We now pass to the transfer salts, the auxiliary muscles for increasing the action in the obliqui, which includes the internal as well as the external obliqui, the action in both sets of muscles receiving important aid from the pair of muscles we shall now bring before you. TJie Action in tlie Transfer salts (lumbo-abdomhialis). — The transversalis (Fig. 12:2) is the innermost of the three muscular layers to the abdomen, the peritoneum covering it, and the viscera lying against it. As the name indicates, the fibres run transversely ; the muscular fibres spring from the internal sur- face of the cartilages of the six inferior ribs, lumbar fascia, crest of ilium, and Poupart's ligament ; while the fibrous aponuerosis in which the muscle-fibres terminate inosculates with that from the opposite muscle in the linea alba, passing under the rec- tus abdominis, forming the inner layer of its sheath, save at the lower portion, where the fibres pass in front of it, blending with the fibrous layer from the internal oblique muscle (Fig. 1 22), the rectus muscle having three layers of fibrous aponeurosis at this point for supporting the muscle, strain tending to fall in THE ACTION IN THE TKAXSVKKSALES. 305 this locality (Fig. 120, E), from the weight in the viscera ; hence this circumstance. And for giving the transverse mus- cles a firm point from which to contract upon the abdominal viscera, the posterior aponeurosis forming the lumber fascia {Fig. 122) is divided up into three broad leaflets, the anterior Fig. 122.— Showing direction of the fibres of the transversalis muscle.— Gray. and middle being inserted into the base and apex of the trans- verse processes of the lumbar vertebrse, and the posterior into the powerful aponeurosis of the latissimus dorsi, so that force with security are insured. Now, then, contraction in the transversales must inevitably diminish the transverse axis in the abdomen ; and should this occur simultaneously with con- traction in the external obliqui (which is the case), it is easily perceived that it would assist the action in these muscles cor- 306 THE ACTION IN THE INTERNAL OBLIQUE MUSCLES. respondingly. It could not do otherwise, in the very nature of things. In short, the whole anterior walls of the abdomen from sternum to pubes are pulled backward by contraction in these muscles, thereby increasing pressure in the abdomen cor- respondingly for compelling the viscera toward the chest during expiration, while the extensive insertions into the ribs should keep them down for increasing pressure in the lungs ; in this way also aiding the external obliqui. Finally, the two pairs of muscles act together and simultaneously, the action alter- nating with the action in the diaphragm ; and by aid of these muscles the mesentery is moved to and fro in a muscular casket, as it were, the great pendulum in the clock-work, by the force in the medulla oblongata. That will answer for res- piration. Now, then, in regard to the action in the pelvic viscera and the mode of concentrating force in the pelvis in connection with the special functions in the viscera. Here comes in the great role in the internal oblique muscles, to which the other two pairs, the transversales especially, are auxiliary ; as also the diaphragm, the whole being available for concentrating force in the pelvis. Concerning the Mechanics for Expelling Waste Prod- ucts in the Pelvic Viscera and the Contents in the Womb. The disposition of force in the walls of the abdomen for compelling out the contents in the pelvic viscera, which func- tion as receptacles for waste products, notably the bladder and rectum, inclusive of the contents in the womb, is also very per- fect. By reason of density in the fsecal matter from absorp- tion of the aqueous portions in the colon, much force is needed for effecting expulsion, which is also available for increasing the action in the bladder and womb during urination and parturition, the parts being fully coordinated with the viscus, by means of the nerves running into them from the spinal axis, as before remarked Now, then, for producing this force we have the following arrangement in the muscles, notably : 1. The powerful internal oblique muscles, or obliqui internus abdominis ascendens (Fig. 126), springing from the middle of the crest of the ilium for two- thirds its length, outer half of Poupart's ligament and lumbar fascia, whence the fibres THE ACTION IN THE INTERNAL OBIIQUE MUSCLES. 307 proceed upward and inward, to be inserted into the lower border of the four inferior ribs, and the whole of the linea alba from the ensiform cartilage to the pnbes by means of the broad aponeurosis, where the fibres inosculate with those from the opposite side Along the border of the upper three- Vortjoincit Tent/on CREMA5TER- Fig. 123.— Showing direction of the fibres of the internal oblique muscle.— Gray. fourths of the rectus abdominis the aponeurosis splits into two layers for embracing the muscle, forming the middle layer of its sheath, but at the lower portion it again comes in front of the muscle, following the course of the transversalis (Fig. 122), and for the same reason; near Poupart's ligament the fibres come downward over the spermatic cord to be inserted 308 THE ACTION IN THE INTEFrXAL OBLIQUE MUSCLES. into the pubes. That will serve the purpose of description. Now, then, what can be the purpose of this arrangement in the fibres of the internal oblique muscle, if it be not for increasing pressure in the pelvis in connection with the special functions in these organs % At the same time, they also assist in flexing the trunk at the lumbar vertebrae, as well as the expiratory effort by pulling the ribs down- ward during this time, and when the action is energetic they pull vigorously npon them. But the major number of the fibres extend out over the walls of the abdomen, and by means of the dense aponeuroses the whole mesentery is em- braced, and when contracting vigorously, as in passing the faecal contents, this is pulled into the excavation, pressed, piston-like, down upon the pelvic viscera for compelling out the contents in the rectum or bladder, as the case may be. First, the body is flexed or bent upon itself (Fig. 124), for shortening the longitudinal axis in the abdomen, which is accomplished by the action of these muscles and the recti abdominis, at the same time the thighs are flexed by the action of the psora and iliaci interni, which brings the long axis in the pelvis in correspondence with the long axis in the abdomen, whereby the force in the diaphragm is brought to bear upon the pelvic viscera. Everything being ready, the diaphragm contracts by inspiratory effort for increasing pressure in the abdomen ; finally, the internal obliqui are put into action, which force the mesentery duwnioard into the excavation (Fie;. 124, 31), the loose coils of intestine glid- ing readily over one another under the force in the abdomen, downward and backward against the rectum (i?), which can- not escape and must endure the pressure, at the same time contracting energetically for assisting the action, while the sphincters expand simultaneously for reducing resistance, as also for obviating strain and rude friction in the parts, otherwise inevitable. It is simply perfect. As will be seen, the ligament is carried downward, and is no longer upon the plane it occu- pies in the erect position or toward the anterior abdominal walls (Fig. 120, 31, E). And by thus pulling the mesenteric piston with great force down upon the bladder and rectum, together with the action in the viscus, the contents are ex- CONCENTRATING FORCE IN THE PELVIC VISCERA. 309 pelled. In short, nothing could be more admirable than the arrangements which obtain for increasing pressure in the pelvic excavation commensurate with the functions in these organs, the same remark applying for every stage in develop- ment. Thus in the quadruped the lumbar vertebrae are flexed Fig. 134.— Longitudinal Section of the Abdomen, showing position of the mesentery during expulsion of waste products. M, middle of mesentery ; I, I, coils of small intestine ; E, anterior abdominal wall ; B, bladder ; R, rectum ; C, colon ; S, stomach ; L, liver ; D, diaphragm ; Q, duodenum ; P, pancreas. by incurvating them upward, which is done by contracting the recti and obliqui, as in man, the muscles upon the dorsal surface at the same time expanding or elongating pari passu with this movement. Then the diaphragm is contracted for shortening the longitudinal axis ; finally, the transversales and internal oblique muscles are energetically contracted for :*10 CONCENTRATING FOllCE IN THE PELVIC VISOKRA. shortening the transverse axis and compelling the mesenteric pi stun into the pelvic excavation. The action is studied to great advantage in the dog and cat, in which the excrement is hard, and Unusual force is needed for expelling it. It goes hard with them, and they work away vigorously in performing it, concentrating their force in the pelvic viscera, the rectum especially, greatly arching the spine upward and bringing the force in the diaphragm and abdominal muscles to bear upon the rectum transmitted through the mesenteric piston. This condition of the rectal contents would explain the great development of the muscles in this locality, which are much more numerous than in any other portion of the canal. In the bladder, on the contrary, the contents are liquid ; hence, not so much force is needed for expelling them, unless, forsooth, there is obstruction to the natural now — e. g., stric- ture— when the walls are hypertrophied, becoming extremely thick in course of time. When the animal desires to pass urine, he puts himself into a proper position, when the me- chanics is set in motion for effecting expulsion, all the parts being coordinated by the central nervous system, so that the whole performs as but a single organ only, as in the case of the rectum. In the parturient woman, this reflex action, which is propa- gated from the viscus through the spinal cord, is forcibly illustrated by simply drawing upon the perineum by means of the index and middle fingers inserted between the labia, when a tremendous expulsive effort at once sets in, the patient contracting the diaphragm and holding her breath, then power- fully contracting the internal oblique and transversales, the womb at the same time contracting, all the parts acting in concert, as in the other cases, the cervix at the same time ex- panding. In the case of birds the legs are brought further under the body, which is tilted a little up anteriorly and lowered pos- teriorly (which favors gravitation) ; at the same time, the abdo- men and cloaca are contracted for expelling the contents, faecal matter or ovum, as the case may be the principle being the same. For expelling the ovum great force is needed, while time is OS SACEUM THE TEUE FLOOR OF THE PELVIS. 311 required for effecting the requisite expansion in the sphincters. The event is announced with great joy. In all the mechanics it is fundamentally the same, requiring the action in the mesen- tery and the muscles in the abdomen, in connection with the action in the special viscus for effecting expulsion of the con- tents. Finally, we have to note several adjustments for conserving structure and increasing function, charming to look upon ; nota- bly : a. The incurvation of the sacrum, which is bent in both the longitudinal and transverse axes, or dished, so to speak, in two directions, the rectum occupying the long diameter, and by means of the articulations with the ilia is inclined at an ob- lique angle with the spine ; in other words, tilted backward in the upper portions ; but being bent upon itself, the lower portion is again brought forward, across the longitudinal axis in the pelvis, and forming with the sacro-ischiadic liga- ments (Fig. 125, 10, 9) the true floor of the pelvis for sus- taining the weight in the viscera and the force in expulsion, the mesenteric piston being driven plump up against it with the rectum sandwiched between them (Fig. 1^4, M, i, R), thereby saving the perineum The rectum, thus lying in the hollow of the sacrum through its whole length, sweeps out over the end of the coccyx to reach the external surface to form the anal opening. It is easily retained in position by means of the overlying peritoneum and connective-tissue fibres, while the terminal end is supported by the broad muscular leaflets of the levator ani (Fig. 1 25, 7), proceeding from the sides of the rectum, to be extensively inserted into the adjacent sides of the pelvis, forming the portion of the floor corresponding with the perineum ; and supporting the bladder and vagina as well. It results, from this arrangement in the parts, that but little of the detrusor force in the abdomen falls directly upon the perineum, the sacrum sustaining it ; at the same time, it is made more effective upon the faecal matter, the rectum, of course, contracting simultaneously for increasing the action, while the levator ani are in concert so as to obviate strain to the perineum, the parts being fully coordinated. The manner Nature has solved this difficult problem in mechanics, which is truly wonderful, must be set down to 812 OFFICE (»F THE LEVATOKES ANT. necessity, and as a prerequisite to the erect position, gradually brought about in connection with the other changes in the pelvic framework. The following illustration (Fig. 126) will show the arrange- ment and distribution of the spinal nerves to the chest and walls of the abdomen. As will be seen, the nerves to the abdominal walls are nearly all intercostals, so called, save the ilio-hypogaster (1G) or first lumbar nerve, to the inguinal regions, but in the abdomen the intercostals are greatly enlarged in correspondence with the amount of muscles for evolving the force in the walls in connection with respira- Fig. 125. — Muscles of the Perineum. — Wilson and Buchanan. tion and the functions in the viscera. And one may readily perceive how the action in the abdomen may be made to alternate with the action in the diaphragm in respiration, since the phrenic nerves are correlated with them in the respiratory centre ; as also how the viscera are brought into correspondence with the walls through the reflex actions set up by means of the pneumogastric and splanchnic nerves, correlated with the intercostal and phrenic nerves. Finally, how sensory impressions in the pelvic viscera should con- centrate the force in the pelvic excavation, in connection with the special functions in these organs, while the enormous web of nerves and nervous ganglia in the hypogastric plexus (Fig. 116), together with the nerves running into it and the special viscera from the spinal axis, notably from the fifth lumbar and sacral nerves (Ibid), would make us readily under- NERVES OF THE ABDOMINAL WALL. 313 stand how the vise as itself should be influenced by the force from the central nervous system, at the same time it effects the actions in the abdominal walls, all the parts acting in concert to this end. It is complex, but readily understood. Fig. 126.— The Nerves of the Abdominal Wall (from Hirsehfeld and Leveille"). 1, Pec- toralis major (cut) ; 2, serratus magnus ; 3, latissimus dorsi ; 4, intercostal muscles ; 5, rectus abdominis ; 6, section of obliquus externus ; 7, obliquus internus ; 8, trans- versalis abdominis ; 9, 9, ninth dorsal nerve ; 10, 10, tenth dorsal nerve ; 11, 11, eleventh dorsal nerve ; 12, 12, twelfth dorsal nerve ; 13, lateral cutaneous branch of first lumbar (iho -hypogastric) ; 14, anterior cutaneous branch of i Ho -hypogastric ; 15, anterior cutaneous branch of ilio-inguinal ; 16, ilio-hypogastric and ilio-inguinal nerves ; 17, lateral cutaneous branch of second intercostal nerve ; 18, lateral cuta- neous branch of intercostal nerve. Concerning the Action in Enusis — The action in emesis is also easily understood. Thus, in place of alternating in their action, as in the usual way in respiration, the muscles in the 314 THE ACTION IN EMESIS. abdomen and diaphragm contract simultaneously and the stomach, caught between these two forces, as in the grip of a vis^\ is compelled to yield up its contents, which is by re- gurgitation ; for the enormous pressure within the abdomen precludes it in the other direction, flowing from high to low pressure, in conformity with organic law. This would ex- Fig. 127. Fig 128. Fig. 127. — Longitudinal Section of the Abdomen, showing position of the mesentery. Fig. 128. — Longitudinal Section of the Abdomen, showing position of the mesentery during vomiting. plain why emesis may be produced when a bladder containing water is substituted for the stomach by irritation propagated from the pharynx, which is obvious enough. But here, as elsewhere, the viscus acts in concert with the muscles in the abdomen, contracting vigorously upon the contents, as in the case of the rectum, bladder and womb, producing a reverse peristalsis, since this would assist the action ; for Nature con- centrates all her available force in expulsive efforts The short, loud inspiratory sound characteristic of vomiting is produced by energetic inspiration suddenly arrested by the stronger action in the abdominal muscles. The above illus- trations will serve for impressing the matter (Figs. 127, 128). TBE ACTION IN EMESIS. 315 Thus the mesentery is forcibly compressed against the stomach under the energetic action of the muscles in the abdomen, the contracted diaphragm being the point of re- sistance, since both act in concert ; while the correlation of the pneamogastric, phrenic, and intercostal nerves in the me- dulla oblongata enables this concert of action in the stomach, diaphragm, and the muscles in the abdomen to be produced. The irritation is propagated from sensory impressions in the gastric mucous membrane, which sets up the action in the me- Fig. 129. — Transverse Section of the Muscles in the Abdominal Walls. — Gray. dulla whence it is reflected over the structures. It is all very simple and easily understood. The extreme pressure upon the liver and gall-bladder would also account for the escape of the bile. The above instructive diagram (Fig. 129) will show the relative position of the muscles in the abdominal walls and the manner the recti abdominis are kept in position by the strong fibrous aponeuroses. In the quadruped the weight of the viscera is largely sustained by these powerful muscular "beams ; at the same time, their aid is readily invoked for assist- ing in flexing the spine at the lumbar vertebrae, for which there is frequent occasion in connection with the functions in the pelvic viscera, as before remarked. In man, still more fre- quently for effecting the bending and stooping posture. CHAPTER XIV. CIRCULATION IN THE EMBRYO, MECHANICAL PRINCIPLE IN. The Embryo, an Aquatic Animal, being Submerged in the Liquor Amnii, Deeply Buried in the Maternal Tissues, and Sustaining Itself the same as the Fishes, only that a Special Arrangement Obtains Respecting it, by Means of which it both Respires and Feeds at One and the Same Time in the Maternal Blood — Placental Souffle the Analogue of Respiration, the Rhythms being as One to Four of the Foetal Heart, or the Same as Obtains in the Lungs and Heart in the Air-Breather — Mode of Connect- ing the Maternal aud Foetal Circulations — The Pumping Action in the Placenta Aspirating the Nutritive and Force-Producing Elements in the Blood in the Sinuses and Expelling "Waste Products — Rhythmical Expansions and Contractions Taking Place in the Womb and Placenta, but which Alternate with Each Other, so that when the Placenta is Expanding, the "Womb is Contracting, and vice versa,' whereby the Blood in the Sinuses is Rapidly Renewed, and Absorption Increased Correspondingly — Nerves for Controlling the Arterial Feeders to the "Womb for Making Circulation in the Sinuses Commensurate with the Physiological Require- ments in the Embryo, and for Producing Correspondence throughout, so that the Pumping Action in the Uterus and its Contents is Made Universal, as in the Air- Breather— Rhythmic Centre for the Pumping Actions Located in the Lumbar En- largement of the Spinal Medulla — The Rhythmic Expansions and Contractions in the "Womb Contrasted with the Action in the Amnion of the " Chick," which is Rocked to and fro in the Egg-Shell by the Rhythmical Expansions and Contrac- tions in the Amnion for Effecting the Requisite Changes of Pressure in the Embryo and Allantois for Increasing Circulation, Making it Commensurate with the Physiological Requirements. This brings us to circulation in the embryo. We have seen that the animal organism is based upon pressure and the power of producing rapid rhythmical changes in pressure for increas- ing circulation commensurate with the physiological require- ments, otherwise impossible ; that respiration and circulation necessarily form a connected movement for producing an uninterrupted and continuous current of the fluids between the cell-brood and environment from which the supplies are obtained, and into which the waste products are returned for redistribution. We now follow this matter and take up circu- lation in the embryo, in order to give the true interpretation of the phenomena, anatomical and physiological, appertaining THE EMBRYO AN AQUATIC ANIMAL. 317 to it also. There is increasing complexity, but from the stand- point afforded by this law for the circulation it is readily explained, so that a mental picture may be formed by aid of illustrative diagrams and the special anatomy. But we must begin with the special environment and the mode of maintain- ing existence. After all, the mammilian is amphibious, the earlier portions of its life being passed under water, since the embryo (Fig. 130) is submerged in the liquor amnii and deeply buried in the maternal tissues, while the arrangements that Fig. 130. — Gravid Human Uterus and Contents, showing the relations of the cord, placenta, membranes, etc., about the end of the seventh month. — Dalton. 1, Decidua vera ; 2, decidua refiexa ; 3, chorion ; 4, amnion. obtain for producing growth and evolving force are funda- mentally the same as in the fishes, due allowance being made for the special environment ; the one feeding and resj)iring in the sea, the other in the maternal blood by means of a com- posite organ known as the placenta, feeding and respiring at the same time through the placental organ, which thus sub- serves a double function, like the intestine in the early stages in development, the animals feeding and respiring through it. And, indeed, a remnant of it is still seen in mammalia in the consumption of air and absorption of oxygen in the stomach when feeding. The physical conditions under which the embryo is evolved 318 THE EMBRYO AN -AQUATJC ANIMAL. determine the special vascular arrangements for effecting cir- culation, while the transformations which accompany this provide for the radical physical changes which are ushered in at the end of the term, when it becomes an air-breather, the fundamental circumstance underlying it all being art adjust- ment with pressure, and the power of effecting rapid rhyth- mical changes in pressure, for compelling circulation in the measure of the physiological requirements. For example, we have seen that the rhythmical expansions and contractions per- vading the body in the air-breather, and known as respiration, compel oxygen and aliment into the circulatory apparatus for evolving force and producing growth ; so, in like manner, a similar necessity exists in the embryo for compelling the nutritive and force-producing elements into its circulation for producing growth and evolving force, which is principally expended in elaborating its structures. But since the embryo feeds in the uterine sinuses from which the commerce is obtained, and into which the waste products are returned, this calls for the differentiation of the placenta organ, which answers to the more highly differentiated lungs and in- testinal canal which are to substitute it at the end of the intra-uterine term as the relative adjustments with the larger environment, lower pressure, and higher order and .amount of work which this involves. The placental souffle, then, which is distinctly heard through the maternal struc- tures, is the analogue of respiration in the air-breather, the relative ratio of the movements to the pulsations in the foetal heart being also the same, or as 1 to 4 of the latter, while the villi are the analogues of the villi in the intestinal canal, the one submerged in the sinuses, the other in the juices in the intestines. Since the pumping action in respiration is absolutely essential for compelling the commerce into the ves- sels, it follows that this circumstance should be represented in the embryo, as the maternal blood does not enter the embryo, the latter feeding out of the sinuses simply by means of the villi in the placenta and this pumping action spoken of ; for here, as elsewhere in the body, there are no means for increas- ing circulation but by rhythmical changes in pressure. The result must, then, be the action in the placenta simulating res- PLACENTAL SOI FFLE THE ANALOGUE OF EESPIEATIOJST. 319 piration. The relative frequency of this movement to the action taking place in the foetal heart is as 1 to 4, or the same as in respiration, as before remarked. Thus, in the case of the placental souffle it is 30 to 35, and in the foetal heart the pulsations are from 120 to 140 per minute ; while, in the case of the air-breather, the pumping action in the trunk or respiration is from 16 to 20, and in the heart from GO to J-0 per minute. Again, this action in the placenta serves not only to pump the fluids into and out of the sinuses, but at the same time it also aspirates the venous blood in the embryo for effecting oxygenation in it the same as obtains in the lungs ; the heart and vessels assisting in the one as well as in the other, since it all forms a connected movement. We now see that by reason of the great increase in pressure that obtains in the embryo, the action in the organs for changing pressure is materially assisted, since the fluids flow more readily in con- sequence. And here comes in the benefit of the amniotic fluid, which not only increases pressure in proportion, but at the same time it serves to transmit the force in the placenta and uterine walls upon the embryo for compelling the blood to and from the sinuses for respiratory purposes, by first increasing, then diminishing pressure in the embryo, which the actions in the womb and placenta must inevitably effect. Thus, when the placenta expands for aspirating the fluids in the uterine sinuses, the organ advances into the uterine cavity, it swells out and occupies more room, in consequence ; and, by thus encroaching upon the embryonic area, it produces corresponding increase in pressure upon the liquor amnii and embryo, with low pressure in itself, which fulfills the con- ditions for increasing circulation from the embryo to the placenta, at the same time that it should aspirate the fluids in the uterine sinuses. It could not do otherwise, in the very nature of things. But during contraction in the placenta, the opposite conditions should obtain, since this would determine high pressure in the latter with low pressure in the embryo, the blood in consequence flowing through the umbilical vein with augmented speed, for the reason that contraction should reduce the volume of the placenta, which would inevitably re- duce pressure in the embryo in proportion, the blood flowing 320 PLACENTAL SCUFFLE THE ANALOGTE OF EESPIRATION. from one into the other in conformity with organic law. To this, again, must be added the action in the foetal heart for aspirating the blood in the placenta. The amniotic media in which the animal lives obviates the necessity for the extensive arrangements for reducing pressure in the chest, which obtain in the lighter media of the atmosphere, the heart, together with the force in the placenta and umbilical vein, being suffi- cient for the purpose. A subaquatic existence calls for but slight reduction in pressure in order to compel circulation ; accordingly, we have the blood rushing into and out of the foetal heart as a result of the rhythmical expansions and contractions taking place in this organ, the same as in the fishes, the principle being the same in this organ ; but for increasing the action, the heart and vessels are more muscular. The right ventricle is thicker and stronger thanilie left, as the relative physiological adjustment with this mechanics, since the force in the diastole is increased correspondingly for aspirating the blood in the umbilical vein and venous system, while the force in the systoles should have similar increase for compelling the blood through the umbilical arteries to the placental tufts and sinuses, the womb and placenta at the same time assisting these actions in the manner as stated, the whole forming a connected movement the same as in respiration, since there can be no doubt that the principle is the same in both, the vascular apparatus and the heart being coordinated with the rjlacenta and womb, the same as in the lungs and muscular envelope in the air-breather, else the relative ratio of the movements would be meaningless. By means of this combined action in the womb and placenta, heart and vessels, together with the high pressure that obtains in the womb, a rapid circulation is readily effected in the embryo and sinuses ; but anything which should reduce pres- sure— e. g , escape of the amniotic fluid— would promptly destroy life. The lividity of the skin, which occurs in these cases, proves conclusively the existence of venous stasis in the systemic capillaries, and insufficiency of the heart's action to carry on circulation in the absence of the normal pressure upon the embryo. How otherwise account for this circum- stance, since the vascular connections are uninjured? More- PLACENTAL SOUFFLE THE ANALOG * E OF RESPIRATION. 321 over, trie same circumstance occurs to the air-breather when pressure is too greatly reduced, as when suddenly carried to too great an altitude in the balloon, the skin becoming livid from venous stasis in the systemic capillaries, producing in- sensibility and death, as occurred in the celebrated case at Paris, in wdiich the voyage was made by two persons, the one losing his life, the other unconscious when the balloon descended ; this notwithstanding the extensive arrangements for changing pressure in the chest, which exist in the latter ; and in persons ascending mountain ranges, respiration and circulation become more and more embarrassed as the journey is proceeded with, and • venous stasis more and more con- spicuous, till the limit of endurance is reached or life itself is terminated. In short, animal life has adjustment with press- ure, and whether in the air-breather or in the embryo, itself, the balance must not be too greatly disturbed, else life would have a speedy termination. Such, in brief, is the principle in the embryonic circulation ; but in order to make the matter fully intelligible and easily understood, it will now be necessary to go briefly over the for- mative changes till the animal is compelled into the great environment and becomes an air-breather, the same as the pa- rent. Commencing with the matrix or mucous membrane of the womb, we have, then, a dense mass of uterine follicles or tubu- lar glands (Fig. 131), packed closely together, the orifices opening upon the mucous surface (, left ovarium and Fallopian, tube ; E, trunk of left sper- matic vein and artery Fig. 140.— Ganglia and Nerves of the entnfflw feft^hvpoVastYicT ganglia, "and giving oft m -j ttj- , ,, -n, ■, c ,. hrMiiphps to the left pub-peritoneal ganglia; P. nsemorr- Gravid Uterus at the End of the hoWal nerves and art.rv r -e off to the sub-peritoneal plexuvte.i^some, nerves passing upward beneath th sub-peritoneal plexuses, and anastomoses treely wmi tnem , , left spermatic ganglion, in v-hich the nerves and artery from the hypogastric ganglion, ana me> branches of the left sub-peritoneal plexuses terminate ,and from wh' h The nerves of the ru°Q;'.° }"J {, are supplied ; X, left sub-peritoneal plexuses covering the body of the uterus; I.leftsu^b^eHtoneaL ganglion, with numerous branches of nerves extending between it and left lipoipstnc nene dnu ganglia ; Z, left common iliac artery cut across and turned aside to expose left hypogastr e nerve ami. ganglion. 334 THE ACTION IN THE MATEKNAL VESSELS. the womb, should also determine the blood in this direction, so that most ample arrangements exist for producing the freest circulation in the placental sinuses. 2. During diastole in the womb and its sinuses, for aspirat- ing the venous blood in the placental sinuses, the high pressure in the arterial system causes the arterial blood to flow into the uterine sinuses as rapidly as the blood coming from the placenta ; at the same time, the valves in the veins of the uterus obviate reflux in the venous system. And when the womb contracts for compelling the blood in the uterine sinuses into the placental sinuses and venous system, the pressure in the arterial system inhibits reflux in this direction. Thus the mechanics for increasing circulation in the uterine and placental sinuses is complete in every respect ; nor does it require extensive expansion and con- traction in the womb in order to effect increased circu- lation through the sinuses, but a moderate and limited amount, sufficient only for producing rhythmical changes in pressure upon the blood, as must appear obvious ; something similar to what takes place in the spongiae, which have muscles (Norway) for producing a more rapid circulation in and out of this canal system ; while in reference to the action in the vessels, their rhythmical expansions and contractions with the movements in the womb and placenta, this has its analogue in the mammalia, the maternal arterial system, which maintains a similar action synchronous with respiration, as has been fully shown ; and is it unreasonable to make similar deduction for the womb and embryo for increasing circulation in them as well, more especially when no other means exist for increasing circulation and for making it commensurate with the physio- logical requirements in the growing embryo ? I think not. This expansion of the womb and arterial feeders would ex- plain the sudden and enormous escape of arterial blood in post- partem haemorrhage, for the placenta being no longer attached, the flow of blood through the uterine sinuses must necessarily be purely arterial. In other words, when contraction ceases and the movement of expansion sets in, the flood-gates are thrown open to the arterial system, hence the rush of blood from it. 1HE KHYTHMIC CENTEE FOR THE WOMB. 335 Inreference to the nervous centre for this pumping action in tlie womb, which answers to respiration in the fcetus. There can be very little doubt but that the spinal cord functions as the common reflex centre of nervous force for producing the rhythmical expansions and contractions in the gravid womb simulating respiration, in short, that the lumbar enlarge- ment of the spinal medulla is in point of fact the respiratory centre for the foetus, regarding the pumping action in the womb and placenta as the respiratory movement, of which there can be but little doubt. And since the local nervous .ganglia control the local actions, maintaining them also in action as in the case of the locomotor apparatus, is it illogical to make the same deduction for the womb and the reflux cen- tre in the spinal cord ? I think not. In short, there must be a nervous centre for coordinating and unifying the movements in every organ, in the uterus as well as elsewhere, as must appear obvious. The following are the reasons for this allega- tion : 1. The very intimate connection subsisting between the womb and spinal cord by means of the hypogastric ganglia and sacral plexus with the intercommunicating nerves extending from the spinal medulla (Fig. 116). y. The fact that the lumbar portion of the spinal cord under- goes enlargement during gestation. 3. The fact that reflex action in the womb is readily pro- duced by applications to the slcin surface, a circumstance well known and practiced by the profession. All these facts, then, fall readily into line when viewed from this stand-point ; and, no scientific reason existing to the con- trary, we may conclude the fact as logically proven, while the vast number of the muscles and nerves in the womb make it absolutely certain there is such rhythmic movement going on. Indeed, the gist of the question is not whether there is a reflex centre in the spinal cord for the womb, but whether this centre produces the rhythmical expansions and contrac- tions in that organ, as alleged. A full and sufficient answer to which is furnished in the fact of the total absorption of the relative phenomena, anatomical and physiological, otherwise utterly inexplicable ; while underneath all which is the organic 330 THE RHYTHMIC CEWTEE FOR THE WOMB. law on which animal life itself is constructed, calling for rhyth- mical changes in pressure in the contents of the gravid womb and in the uterine sinuses for increasing circulation, and for making it commensurate with the physiological requirements in the embryo ; otherwise impossible. Nor is it reasonable that the enormous number of muscles and nerves in the womb are for compelling out the contents at the end of the term sim- ply ; but, on the contrary, tluit they perform an active and essential part in the worlc of construction which precedes ex- pulsion. Beyond a shadow of a doubt, they are not idle in all this while, especially when supreme necessity would have it otherwise ; on the contrary, they are evolved as force is needed for carrying on circulation, while at the end of the term they are available for assisting in expelling the embryo ; hence, per- form an active role from the beginning to the end of their ex- istence, as is ever the case with the muscles and nerves. One other circumstance in this connection, namely : the very tortuous course of the arteries in the womb (Fig. 139, u), which undoubtedly has reference to this action in the womb, permitting the rhythmical expansions and contractions to take place without involving strain to the vessels, other- wise inevitable. The veins, it will be perceived, take a straight course, while the arteries are serpentine or bent upon themselves. Ihis is due to the fact that the veins are more extensile, and possess greater powers of elongating and shortening than the arteries, the yellow elastic coat of the latter tending to limit their actions. It will be remem- bered that this circumstance has forcible illustration in the splenic artery and vein, the former being almos-t twice the length of the latter, to allow for expansion in the stomach when food is taken ; otherwise, this would involve rjrodigious strain to the vessels, with great reduction of the calibre. But the same remark will apply to the vessels of all the hollow viscera. Thus, everything is in correspondence. Of course, the movement in the womb and placenta is necessarily more limited than in the lungs, in which considerable space is re- quired for sucking in the air simultaneously with the venous blood, but which would not apply for the fcetal circulation, as the oxygen is furnished by arterial blood at one and the same EXPELLING THE UTERINE CONTENTS. 337 time with, the nutritive and force-producing elements, which the scheme calls for in order to generate force, since it is by a combination of the two that force is evolved, as before re- marked. In fine, differentiation in the organs cannot, for obvious reasons, work any change in the fundamental principle underlying the mechanics for increasing circulation, which is by rhythmical changes in pressure involving a pumping action for compelling the commerce in the blood-vessels and expelling waste products, while the speed of the currents thus produced is determined by the rapidity and energy of the rhythmical expansions and contractions pervading the organs, inclusive of the heart and vessels, since it all forms a connected movement for increasing circulation between the cell-brood and environ- ment, from which everything is obtained and into which, in due time, everything is returned for redistribution, in the embryo the same as in the maternal tissues, only the journey to and from the environment is by way of the maternal blood- vessels, inclusive of the uterine sinuses, the common ground where interchange is effected betwen the maternal and foetal blood. With the expiration of the intra-uterine term, expansion of the maternal passages sets in for reducing resistance to the egress of the embryo, and the womb and abdomen contracting simultaneously for increasing pressure in the womb, the con- tents are compelled into the environment. Here, as else- where, the law of pressure applies for compelling movement in the contents ofthehollow viscera, for which special adjust- ments obtain in the organs and organism, the underlying principle being ryhthmical changes in pressure. Pressure being invisible, it is difficult to realize the impor- tant relations it sustains to the mechanics and the enormous role it performs in the organism ; nevertheless, the fact is in- controvertible that from centre to circumference, and from surface to surface of the body, it is the fundamental and con- trolling circumstance, the foundation, so to speak, of the tem- ple, pervading the superstructure, and interwoven with all the phenomena, which spring out of it as waters from a fountain. It is passing strange the matter should have escaped atten- tion so long, especially in this age, when thought is reaching 338 CHANGES IN THE MECHANICS PRODUCED BY BIRTH. down into the organic basis of life. Indeed, one needs to go there if he would unravel the tangled skein in animal struc- ture and function, since the definite arrangements that obtain in the organs with every stage in development show unmis- takably a common relation to fundamental forces in Nature underlying it all, notably pressure and gravitation, while the arrangements which obtain in the structures represent the relative adjustments for special work, and in the mea ure of it. Respiration in the New-born : The Change in Mechanics which this Involves. — The first thing in the new-born is to start respiration for compelling in the commerce in the environ- ment in place of the uterine sinuses, and the action in the placenta for which this is the substitute, the oxygen pass- ing in by way of the lungs and the aliment through the intestinal canal. But it requires fresh adjustments in the mechanics of circulation to bring it in correspondence with this circumstance ; notably, circulation of the blood in the lungs, and the attaching of the intestinal apparatus to this movement by means of the nerves connecting in the medulla oblongata, a matter which has already been fully considered in the preceding pages. The first thing, therefore, is to start respiration, when it will be in order to consider how the me- chanics in circulation swings into this pendulum movement for compelling correspondence throughout, with the blood ever flowing from high to low pressure, in conformity with the or- ganic law underlying the organism itself. One end of the nervous system, so to speak, is spread out in the skin surface, the other through the organism, while the medulla oblongata functions as the common centre to it all ; any impression, therefore, made upon the skin surface is promptly reflected to the medulla oblongata, thence over all the structures for pro- ducing the reflex actions connected with respiration and circu- lation. The irritations attendant upon parturition from fric- tion against the maternal structures are calculated to produce these reflex actions ; but the contact of the sentient surface with the stimulus in the atmosphere itself would also excite it. And if the child should be injured by the rude experi- ences incidental to parturition, a yet more powerful means for CHANGES IN THE MECHANICS PRODUCED BY BIRTH. 339 exciting the reflex actions connected with respiration is fur- nished by the sudden application of cold to the surface, as in sprinkling cold water upon it,* or a sudden, sharp slap with the open hand may be substituted instead, as is com- monly practiced. Last, but not least, carbonic acid, as it ac- cumulates in the blood, acts as a special stimulus to respira- tion. It cries out in pain, and, presto ! the haemal mechanics is changed. The low pressure which is produced in the alveoli by expansion of the lungs during inspiration compels simul- taneous afflux of air and blood in the alveoli ; while the high pressure which is produced by the subsequent contraction during expiration causes simultaneous efflux in these fluids, which flow from high to low pressure in conformity with organic law — the one flowing out by reflux action through the route of ingress, the other passing into the left chambers of the heart and arterial system on its way to the cell-brood, as has already been described in the air-breather. This aban- donment of the old route for the new is readily explained, since it is in strict accordance with physical law, being in the direction of least resistance. For example, we begin the mechanics with high rjressure in the arterial system, since this extends through the ductus ar- teriosus to the semilunar valves of the pulmonary artery, the floor of support to the arterial column. Hence, when the alveoli expand during inspiration for sucking in air through the trachea, the high pressure in the pulmonary artery and ductus arteriosus compels this blood to flow straight on to the low-pressure areas in the alveoli simultaneously with the afflux of air, or in the direction of least resistance, in place of forcing its way into the arterial system against high pressure, which would be contrary to law. And the ductus arteriosus, though still filled with blood, as in the case of an artery, be- yond the ligature to where a collateral branch is given off, shrinks and contracts till it becomes a solid, impervioas cord. For closing the foramen ovale, the following mechanics * The intimate connection subsisting between the respiratory cpntre and the skin surface is of easy demonstration in the adult by the same means. For example, every impact of cold water against the skin products spasmodic inspiration or expansion in the lungs ; not deep, however, but very energetic. 340 CHANGES IN 'JHE MECHANICS PRODUCED BY BIRTH. apply : After birth, the inpour of blood in the left auricle by way of the pulmonary veins is as rapid as it is in the right auricle through the venae cavae, and with pressure at equilibrium in the two auricles, this at once suspends all tendency in the blood to pass from one side into the other during auricular diastole ; while during the auricular systole and the high pressure this produces in the auricles, causes the blood to flow into the expanding ventricles, where low pressure invites it, at the same time gravitation also should compel it in this direction, since the ventricles are under the auricles, the same applying for either auricle. Thus, a dual force applies (suction and gravitation) for compelling this blood into the ventricles during the auricular systole, and the foramen ovale, being thus abandoned, is closed and obliterated by membranous formation. But in intra-uterine life the matter is different ; here the wThole blood is poured into the right auricle, that from the upper cava passing at once into the right ventricle, while that in the lower cava (which includes the blood from the umbilical vein) passes through the right into the left auricle, with which it directly communicates, guided by the Eustachian valve, but also pushed over and deflected in this direction by the weight of the descending current from the npper cava ; but if the head be downward (which is generally the case), then by its own weight the blood would gravitate in this direction, the influx of blood from the upper cava also compelling it. And with the absence of blood as a counter-force in the left auricle, this blood is necessarily compelled into the latter, thence into the left ventricle and aorta, while that in the right ventricle passes into the arterial system at the aortic arch by way of the pulmo- nary artery and ductus arteriosus. After birth, however, the pumping action in the lungs reverses all this, in maimer as above described. The pulmonary artery in the embryo, in place of discharging through the lungs, left auricle and ven- tricle, empties its blood at once into the aorta as it passes under the arch, and which is also in the direction of least re- sistance, ^ince it is impossible for this blood to thread its way through the capillary meshes of the unexpanded alveoli ; a cir- cumstance which has forcible illustration in the air-breather, PHYSIOLOGY OF THE ALR-< HAMBER IN THE EGG. 341 and when the alveoli are filled with residual air, by simply inhibiting inspiration by closing the mouth and nose so as to prevent expansion in the lungs, the blood, in consequence, rapidly accumulating in the right side of the heart and venous system. In the space of a minute there is lividity of the lips and whole cutaneous surface from venous stasis in the sys- temic capillaries. If longer than this, an appalling venous suffusion pervades the surface ; in the face most, for this is the most vascular portion, with the large venous trunks in close proximity to the heart. Even the eyes are forced out- ward, becoming prominent from distension of the intra-orbital veins caused by obstruction in the cavernous and lateral sinuses But the instant the obstruction is removed and the lungs are permitted to expand, so as to reduce the intra- pulmonic pressure, the dammed-up blood surges into the alveoli, and all runs on as before. In other words, the heart and vessels are unable to carry on circulation in the absence of the pumping action in the lungs, for which afflux and efflux of air is essential ; all of which has been sufficiently explained in the preceding pages. Concerning Incubation and Circulation in the Egg. — Why should there be an air-chamber to the egg (Figs. 141 and 142) ? We are now prepared to furnish a scientific explanation to this physiological problem, otherwise inexplicable, viz. : the con- tents of the egg for developing the chick are inclosed by a firm, unyielding wall of living marble, and since the animal circula- tion is dependent upon rapid rhythmical changes in pressure, it follows that provision should be made within the shell for effecting this ; otherwise the actions in the heart and vessels could not take place. This air-chamber (a), together with the important relations it sustains to circulation and elaboration in the growing chick, organilogically, therefore, must be regarded as one of the most essential and important elements in egg- structure, the underlying principle to all the nutritive changes which are ushered in under the action of external tempera- ture. The accompanying illustration (Fig. 142) will serve for impressing the matter. The discipline in the nutritive processes requires the blood to be brought from the vitellus and aerated in the allantois, 342 PHYSIOLOGY OF THE AIR-CHAMBER IN THE EGG. thence to be dispatched through the body territories. Accord- ingly, two great venous trunks (omphalo-meseraic veins), one in each fold of the splanchnopleure, embracing the vitellus, are the first evolved, while at the terminal ends or confluence the heart is formed by the blending of the walls of these venous trunks. Fig. 141. — Anatomy of the Egg. — Jones, a, b. Air- vesicle ; 6, arrow indicating the position of the central axis of the egg ; c, the yolk ; /. Purkinjean vesicle ; g, cicatricula ; h, thickening of the vitelline membrane ; e, canal leading to d, the cen- tral chamber of the yolk. Fig. 142. — Egg of Fowl in Process of Development, showing area vasculosa, with vitelline circulation, terminal sinus, etc. — Dalton. According to His. the heart is developed by the coalescence of a layer of the splanchnopleure with a similar layer from the somatopleure, the hollow cavity formed by the union being in free communication with the adjacent omphalo-meseraic veins. According to Foster and Balfour, " the upper end of the heart is developed out of the mesoblast of the splanchnopleure," but "increases in length step by step at the expense of the con- PHYSIOLOGY OF THE CIKCULATIOX. B43 tinually coalescing omphalo-meseraic veins." Thus the fact is undeniable, that the heart is developed in the venous system in connection with the vitellus. The rhythmical expansions and contractions in this organ (the punctum saliens of early authors) serve to pump the vitelline fluids in the bulbus arteriosus and the two aortse which are developing at the other end of the heart. But for this air-cushion within the egg (Fig. 141, a, b), neither these rhythmical expansions in the heart nor the changes in pressure for compelling circulation in the vitelline fluids could take place, since the unyielding shell would inhibit these actions, as must appear obvious. Respiration is provided for in the following manner : The allantois (a diverticulum of the intestinal canal) is pushed out around the amnion which contains the embryo, and expanding its vast capillary network of vessels (whose footstalks spring from the two iliac arteries, as do the umbilical arteries in the mammalian embryo) against the shell-membrane or chorion, becomes the respiratory organ of the chick, by means of which the venous blood is constantly arterialized, the oxygen passing in and the carbonic acid passing out through the pores in the shell by the action of the polar forces. But "at the time the heart first begins to beat, the capillary system of the vascular and pellucid areas is not yet completed, and the fluid which is at first driven by the heart contains, according to most ob- servers, very few corpuscles The course of the blood then, during the latter half of the second day, may be described as follows : The blood brought by the omphalo- meseraic veins falls into the twisted cavity of the heart, and is driven thence through the bulbus arteriosus and aortic arches into the aortic trunk. From the aorta by far the greater part of the blood flows into the omphalo-meseraic arteries, only a small amount passing on into the caudal terminations. From the capillary network of the vascular and pellucid area into which the omphalo-meseraic arteries discharge their contents, part of the blood is gathered up at once into the lateral or direct trunks of the omphalo-meseraic veins. Part, however, goes into the middle region of each lateral half of the sinus terminalis, and there divides on each side into two streams. One stream and that the larger one, flows in a forward direc- 344 PHYSIOLOGY OF THE CIRCULATION. tion until it reaches the point opposite the head, thence it returns by the veins spoken ol above, straight to the omphalo- meseraic trunks. The other stream flows backward, and be- comes lost at the point opposite the tail."* The following from the same authors is deeply suggestive : " ISoon after its formation the heart begins to beat, at first slow and rare pulsations, beginning at the venous and passing on to the arterial end. It is of some interest to note that its func- tional activity commences long before the cells of which it is composed shoio any distinct differentiation into muscular or nervous elements." It would be difficult to overestimate this circumstance, since it establishes beyond peradventure the power in the higher as in lower animals to effect rhythmical expansions and contractions in the soft tissues in the absence of any muscle or nerve for producing them. But at present the significance of these rhythmical expansions and contractions taking place in the heart concerns us most, since the manifest purpose is to increase circulation ; and as this can only be done by pumping the blood of the omphalo-meseraic veins, it fol- lows that both expansion and contraction is necessary for accomplishing this — the one for aspirating, the other for pro- pelling it. This would explain why the action should begin at this end of the heart. Of course, as the area of circu- lation increases this would call for corresponding increase of force for effecting it. Accordingly, pressure is increased at the same time that additional force is placed upon it ; notably, by the amniotic fluid and by the action in the amnion, the muscles and nerves in the heart and vessels being in cor- respondence. The amnion closes around the embryo of the chick on the fourth day, and on the fifth fluid begins to collect in the sac, and by the seventh the embryo is submerged in a considerable quantity of water. "By the seventh day very obvious move- ments begin to appear in the amnion itself ; slow vermicular contractions creep rhythmically over it. The amnion, in fact, begins to pulsate slowly and rhythmically, and by its pulsa- tions the embryo is rocked to and fro in the egg. This pulsation * Foster and Balfour's "Embryology." PHYSIOLOGY OF THE CIRCULATION. 345 is due, probably, to the contraction of involuntary muscular fibres, which seem to be present in the attenuated portion of the mesoblast, forming part of the amniotic fold" (Foster and Balfour). The physiological significance Of this accumulation of amni- otic fluid, and the rhythmical contractions and expansions in the amnion, may not be doubted for a single moment, since the former would increase pressure, while the latter should produce the necessary changes in pressure in the embryo for compelling respiration and circulation to be in correspondence with the nutritive and functional processes in the growing chick, both of which are constantly extending their limits and requiring more and more force for effecting them. These slow pulsations in the amnion of the chick answer to the placental and uterine souffle in gestation, the principle being precisely the same. How otherwise explain this circumstance % But, as has already been remarked, all pulsations relate to changes in pressure, and these pulsations in the amnion, together with the amniotic fluid, relate to changes in pressure in the embryo for increasing circulation of the juices. The explanation of the mechanics is sufficiently easy ; nota- bly, there are two cardinal points from which to regard it — one in the allantois, the other in the embryo. They may be re- garded as the poles to this circulation, in which the action alternates for assisting the circulation by rhythmical changes in pressure, and following each other in regular order and suc- cession readily produce afflux and efflux of the fluids commen- surate with the physiological requirements. First, commencing with the movement of expansion in the allantois. The increase in pressure which this produces in the embryo through the amniotic fluid occupying more room, consequently encroaching upon the amniotic area, should cause a corresponding amount of the venous blood to flow with increased energy toward the allantois, the point of low pressure within the egg (the heart and vascular system, of course, assisting in this) ; and nice versa during contraction. The rhythmical contractions and expansions in the amnion have the effect of increasing and diminishing pressure in the embryo itself, and by relieving pressure in the allantois, enables this to expand pari passu 346 PHYSIOLOGY OF THE CIRCULATION". with, contraction in the amnion for aspirating the venous blood, at the same time that it aspirates the air through the outer membrane and pores of the shell. But when the move- ment is reversed by expansion of the amnion, the reduction in pressure which this effects in the embryo, together with the simultaneous increase of pressure it produces in the allan- tois by forcibly compressing this against the shell wall, causes the aerated blood in the latter to flow with augmented speed into the heart of the embryo, the allantois, itself, also partici- pating in this action, the fluid it contains enabling it to effect such rhythmical compression of the capillary plexuses (Fig. 14:5). The following forcible illustration (Fig. 144) by the dis- tinguished biologist at Jena will serve to impress the matter It represents early stage in development (third week in gesta- tion) in the human embryo, it will be seen that pressure is increased at the cardinal points, namely, vitellus (a), the body of the embryo (c), and placenta (5), which is fundamentally the same as the allantois, though the office of the latter is mainly respiratory. As the embryo and allantois are elabo- rated out of the material in the vitellus, this would explain the greater accumulation of fluid in this locality for com- pelling circulation toward those two points, while the rhyth- mical contractions of the yolk sac should greatly expedite it. For increasing circulation between the embryo and placenta (c, b), commensurate pressure is produced by accumulation of fluid in these two points or poles of this circulation. This, together with the action in the membranes themselves, and the heart and vessels, is sufficient for carrying on circulation in the initial stages of embryonic evolution ; but with the in- crease of growth comes increasing difficulty for effecting it : hence the pumping action which is set up in the placenta and womb, together with the accumulation of amniotic fluid for transmitting these actions upon the embryo, as described above. Thus, everything is in correspondence — the liquor amnii, the increasing growth of the placenta and the number of muscles and nerves in the walls of the womb — and so con- tinues till the close of pregnancy. In other words, it all forms a connected whole in the mechanics of the embryonic circu- lation. The absence of a shell wall permits expansion in the PHYSIOLOGY OF THE CIRCULATION. 347 chorion pari passu with the growth of the embryo, while the womb expands in concert with this action in the chorion and embryo. Pig. 143.— Diagram of Young Embryo (Chick) and its Vessels, showing circulation of umbilical vesicles, and also that of allantois, beginning to be formed. — Dalton. Pig. 144. — Human Embryo in the Third Week. — Haeckel. «, Large globular yolk sac ; b, allantois ; c, amnion ; d, tufted chorion. There are yet no limbs. In the case of the bird, the pumping action in the abdomen (the soft hinder parts of the bird) for pumping air and blood through the alveoli, is set up in the latter days of incubation, when rapid atrophic changes soon separate the umbilical ves- sels, and, breaking the now attenuated and fragile shell wall 348 PHYSIOLOGY OF TIIE CIRCULATION. with its beak, it finally makes its escape, leaving the allantoic and atrophied membranes behind. Fig. 145. — Ovum from the Mule. — l,eydig. u, Nucleus ; b, cell body ; c, thickened corpuscle traversed by pores. Fig. 146. — The Human Egg from the Ovary of the Female ; much enlarged. — Haeckel. The entire egg is a simple, globular cell. The greater part of the spherical egg-cell is formed by the egg-yolk, or the granular cell-substance (protoplasm), which is com- posed of innumerable delicate yolk granules, with a little intervening substance. The germ- vesicle, answering to the cell-kernel (nucleus) lies in the upper part of the yolk. It contains a dark nucleolus or germ spot. The globular mass of yolk is suiTOunded by a thick transparent egg membrane {znna jiellueida). This is penetrated by the pore- canals, in the form of very numerous hair-like Unes, which run rapidly toward the centre of the globe ; through these the thread-shaped, moving sperm-cells pass, in the process of impregnation, into the egg-yolk. The common relation which animal life sustains to the or- ganic laws has forcible illustration in the very ova, the struc- ture being fundamentally the same (Figs 145, 146). CHAPTER XV. ANIMAL TEMPERATURE AND THE NECESSITY FOR A THERMIC CENTRE IN THE MEDULLA OBLONGATA. Body-Temperature — Why the Thermic Centre Should be Correlated with the Respira- tory, Vaso-Motor and Voluntary-Motor Centres in the Medulla Oblongata — Relations which Respiration Sustains to Metabolism — Ditto, Metabolism to Body- Temperature — The Vaso-Motor Centre and the Vascular Arrangements in the Skin for Reducing Excessive Body-Temperature so as to Maintain a Balance in Temperature in the Organism — Mode of Imitating This in Febrile Conditions by Therapeutical Device as the Most Effective Means of Controlling Body-Temperature, Thereby Conserving Life and Expediting Recovery — Use of Respiratory Sedatives in Connection There- with, and Rationale of — Peculiarities that Obtain in Dogs and Birds for Facilitating Discharge of Body-Temperature when Excessive — Seat of Oxidation. Temperature is treated more advantageously in connection, with development, maintaining mobility among the molecules, for which a special physiological adjustment obtains in the organism, but which differs in the plants, as well as in the animals, though the oscillations from the norm in any one of them is very limited, and the sliding scale in the warm- blooded may be roughly estimated at from six to ten degrees only, either a fall or rise in body-temperature of several degrees speedily bringing life to an end. It will be neces- sary, however, to briefly refer to it here in order to show the relations which body-temperature sustains to respiration and circulation, whereby it is regulated so as to maintain a balance in the organism ; otherwise impossible. And here we have to mention that the thermic centre for the organism (which is now almost universally conceded the elaborate researches of Pfluger, making the argument unanswerable) is also correlated with the other nervous centres in the medulla oblongata, or respiratory, vaso-motor, voluntary-motor and thermic, making four in all, unless the trophic be also included, which would seem reasonable and natural, since nutrition necessarily de- pends upon temperature and circulation. 350 FOUR NE1IVOUS CENTRES IN THE MEDULLA OBLONGATA. The reasons upon which this opinion is based would seem to be incontrovertible. Briefly summarized, they are as fol- lows : First and foremost, the scheme calls for this in order to pro- duce continuity in force, otherwise impossible, and the me- dulla oblongata being the common centre of nervous force for the organism, it would naturally include the thermic centre. 2. Since heat is the product of metabolism or the nutritive and chemical changes going on in the body, but principally the latter, Tjroduced by the oxidizing processes generating carbonic acid, especially in the muscles during musculation, and the commerce is pumped through the tissues for the pur- pose by means of respiration and the pumping actions in the heart and vessels, as has been fully shown ; it follows that the thermic centre should be correlated with the respiratory and vaso -motor centres for compelling prompt response in order to evolve heat in the measure of the physiological requirements, furnishing the requisite fuel for the purpose, otherwise im- possible ; hence the correlation of the thermic with these other two centres. 3. Active musculation is the principal means for rapidly generating heat in the body ; but since the muscles can en- dure but a limited amount of heat above the norm, which is 93.5 degrees Fahr. for man, it follows that there must be some ready means for rapidly bringing the blood to the skin-surface when body-temperature is excessive, for effecting reduction in temper- ature by means of radiation and evaporation effected by means of sweat, which is poured out for the purpose, the vast capil- lary network in the skin being widely expanded for the pur- pose, producing the characteristic flushing of the skin during active exercise ; but in order to accomplish these results, the thermic centre would have to be correlated with the vaso- motor centre for compelling prompt response in the vessels in the measure of the requirements. In fine, respiration, circulation and temperature rise and fall together, rising and falling with the activities; while the vaso-motor centre, by being connected with the thermic centre, compels the local actions in the skin for maintaining a balance in tempera- ture ; otherwise, the muscles would be destroyed in their own THE AUTOMATIC FUEISTACE IN THE TISSUES. 351 heat, and the activities would be speedily fatal, as must ap- pear obvious. Hence, the correlation of the thermic centre with the respiratory, vaso-motor and voluntary-motor centres the whole being woven in and in, and must be so, in the very nature of things. Loss in body-temperature is announced by sensory impressions in the skin ; the animal shivers, the teeth chatter, and the furnace is set going again for raising temperature, the animal moving about restlessly for starting the action in the muscles, doing so unconsciously, hut forced to it by imperative demand in the organism. This hurries respiration and circulation for supplying the fuel, which soon puts up temperature to the norm again. At the same time the appetite is increased, while the digestive and assimi- lative processes are more active, and from these combined sources temperature soon rises with the swell in the activities, which puts up respiration and circulation correspondingly ; so that prompt help comes with the supply of food, while force and fnel are economized, if the animal be housed so as to diminish external cold, and especially if protected by suitable clothing for diminishing radiation and conduction, the heavy coat of hair which is developed with the accession of cold weather subserving this function in the animals, while man long since has learned the art to perfection by raiding them for their shaggy coats, at the same time aiding himself with fire or artificial heat. But the physiological fact to be kept uppermost in the mind is the correlation of the great nervous centres in the medulla oblongata, making respiration the basis of all the movements, while the exhalation of car- bonic acid from the lungs is, so to speak, the smoke of the automatic furnace, the principle being the same precisely as obtains in a grate and the burning of coal; only, that the tissues subserve the purpose of a grate, the fuel furnished by means of respiration and circulation, while the pumping actions invoke the law of pressure which applies for compel- ling supply to be equal to demand. All plain enough, and easily understood from the stand-point of the law underlying the organism and the action of the special forces which apply in the case. The increase in temperature when the bodily activities are 352 MAINTAINING A BALANCE IN TEMPERATURE. in abeyance, is produced by prolonged and excessive reflex irri- tation propagated from the mucous surface of some of the organs, or from the skin, or by blood-poison, as in traumatism and the essential fevers acting directly upon the nervous centres of res- piration and circulation, and in the fact of retrograde metamor- phosis from loss of vitality produced by the disturbed balance, the supply of oxygen brought into the tissues by the increased respiration and circulation being greatly in excess of the de- mands, consequently tending to excessive oxidation and retro- grade metamorphosis, whereby the tissues are consumed and rapid wasting and shrinkage result as an inevitable sequence, while the matter is due entirely to excessive stimulation of the respiratory and vaso-motor centres. Take the temperature and count the respirations and the rhythms in the heart and arteries, in proof of this statement. Yes, there is correspondence. Now, then, how account for this circumstance, but in the correla- lation of the three nervous centres, as alleged \ And if the respiratory and vaso-motor are in the medulla oblongata, it follows that the thermic centre is also there, for in no other way could continuity in force be produced for effecting this cycle of motion. Then, again, when temperature falls, as in the crisis, respiration and circulation are in corre- spondence, at the same time shifting the blood to the surface in order to cool it ; the skin is reeking with perspiration welling out of every pore for carrying off temperature, the same as in bodily exercise — an heroic effort of life to throw off the toils in which she is caught by the very nature of her framework, and the rude experiences to which the animal is exposed. It is thought by some* that the action in the vaso-motor centre would explain the phenomena, but the respiratory should be included as well, so as to diminish the supplies, while there must be a heat-centre, one exceedingly sensitive to heat, for due notification of local increase with the power of promptly compelling the requisite vascular changes in the skin and internal parts for rapidly expanding the external and con- tracting the internal vessels, at the same time producing copious perspiration ; otherwise life would suffer speedy ex- * Pfluger's Archiv., iii. (1870, 504 ; ibid., v. (1872). 77. Heidenhain. PHYSIOLOGY OF FEVFK. 853 tinction by the voluntary movements themselves, not to men- tion the reflex irritations and the action of blood-poison, as must appear obvious. It follows that the thermic centre must be correlated necessarily with the other centres in the medulla oblongata, the solar centre for the organism. Take a very simple, as also a very common case, notably, acute tonsillitis in the child. It is notorious that body-temperature rushes up with extraordinary rapidity in this condition. Why? The explanation is easy. Thus, the tonsils are in close proximity to the medulla oblongata, immediately adjacent — you might say right in front of it, so short the distance between them ; hence, reflex irritation falls at once, and with all of its force, upon the respiratory and vaso-motor cen- tres, and the increased rhythms which this produces by com- pelling excessive importations of the commerce into the organism and the tissues rush up the temperature corre- spondingly from the excessive oxidation it induces. In- deed, a fretful child may readily induce a febrile paroxysm at any time by a violent fit of crying, but the sleep which fol- lows close upon exhaustion, by slowing respiration and circu- lation, together with the copious diarjhoresis which accompa- nies it, soon reduces temperature to the norm again, so that everything runs on as before. The practical deduction to be drawn therefrom in the treatment of the essential fevers — to induce sleep artificially by means of chloral, etc., at the same time bathing the skin, or rather keeping the surface wet by means of cloths steeped in warm water — e. g., sponging the night-clothes with this so as to obviate shock or arouse the patient ; otherwise inevitable. More of this presently. In cases of extensive burns and scalds, which are always fol- lowed by increased respiration and circulation, producing fever, how explain this circumstance if not by reflex irritation in the respiratory and vaso-motor centres, thereby producing increased respiration and circulation, and making oxidation excessive in the tissues ? The very principle in the mechanism lays the whole thing bare. The office of therapeusis is, of course, to repress the irritation by appropriate local and con- stitutional remedies, or by soothing applications and excluding the air, at the same time administering the salts of morphia, 354 PHYSIOLOGY OF FEVER. etc., supporting the patient. In the case of blood-poisoning, permanent relief comes only by eliminating the materies morbi through the special emunctories ; Medicine, as it were, sitting by the tiller and guiding the life-boat so as to keep it off the rocks and dangerous shoals, clear of the breakers and in the deep water, by keeping down excessive temperature by respira- tory sedatives for reducing the rhythms in the lungs and circulatory apparatus, at the same time reducing temperature in the manner as stated, repeatedly applying the thermometer to learn the state of the temperature, saving the patient by constant vigilance. And Medicine is made a helpmate, not an executioner, for struggling life. The intimate relations which the skin sustains to the respiratory and vaso-motor centres, by reason of the sensory nerves, would account for fever induced by irritations of any kind, e. g., the exanthemata, which independent of the special action of the materies morbi upon the nervous centres, interfere with transpiration, consequently producing an accumulation of heat, as it were, damming it in the deap vessels, thereby preventing its due escape from the skin-surface. The high temperature in this class of cases is undoubtedly due to accelerated respiration from excessive stimulation of the respiratory centre from reflex actions in the skin, together with the suppression of the secretory functions in the skin for carrying off excessive temperature. The role in therapeusis, however, is clear — namely, repress excessive temperature in the manner as stated. Small-pox, so malig- nant in times past, when the patients were treated in close rooms, but now in open wards and tents, where freest ingress of air is insured, reduces body-temperature by conduction, with very little mortality. In all these cases there is rapid respiration, induced by excessive irritation in the skin, com- bined with the direct action of the materies morbi upon the respiratory and vaso-motor centres. In addition to frequent bathing of the skin, for supplementing perspiration, some respiratory sedative, so as to induce sleep, e. g., quinine, chloral, etc., should be administered in cases of alarming temperature, as where it exceeds 105° Fahr. In sleep, tem- perature falls because respiration falls in frequency. And convalescence in fever is ushered in by sleep; sleep and PHYSIOLOGY OF FEVEK. 355 diaphoresis, the slowing of respiration and the escape of heat by evaporation putting an end to the fever. The explanation of the fall in temperature produced by the slowing of the respiratory rhythms is obvious enough. Thus, taking the average in man, sixteen respiratory rhythms are sufficient for maintaining the body-temperature at 98. 5 degrees Fahr. , each volume of air inspired representing, of course, a given volume of oxygen, which is sufficient for maintain- ing the norm. In other words, sixteen pumps of the respi- ratory mechanism (which, of course, would include the ac- tions in the heart and blood-vessels, since it all forms a con- nected movement) are sufficient for maintaining the body-tem- perature at 98.5 degrees Fahr. Now, then, any circumstance which should increase the rhythms would produce corre- sponding elevation of the temperature, but for the compre- hensive arrangements that obtain for discharging heat from the body-surface for maintaining a balance, already referred to ; but in abnormal conditions this is more or less inter- rupted. And for that reason the public speaker "warms up" as he proceeds in his subject, speaking more and more rapidly, tem- perature rising correspondingly. It is the same in the vocalist, as i have proven over and over again, by taking the temperature before the commencement of the exercise, during it, and afterward, and while the tem- perature varied somewhat, always finding it higher than be- fore, from one to two degrees, according to the energy in the respiratory rhythms. When the temperature increases from one to two degrees, the balance is struck by reason of the action in the skin ; else he must stop, from exhaustion induced by the action of temperature upon the nervous apparatus, which is Nature' s method for putting an end to the exercise. But muscu- lar exertion of any kind produces increase in temperature ! Of course it does ; but is not respiration in correspondence? So, likewise, the action induced by cold, since this rapidly with- draws heat, and respiration must be hurried correspondingly for maintaining a balance ; otherwise impossible. And when the air is loaded with moisture which rapidly absorbs body- temperature, the individual exposed to it had better keep the 366 NECESSITY FOR A THEItMIC CENTRE. muscles in action for rapidly evolving heat, and he "sits" at his peril. For dismissing heat, the vessels in the skin are ex- panded, and the deep vessels contracted ; but for retain- ing it, the surface vessels are contracted, and those in the deep territories are expanded correspondingly, in order to shift the blood from one to the other part, at the same time increasing respiration for supplying the additional quantity of fuel and oxygen which are called for for evolving heat and maintaining a balance in the organism, otherwise impossible. Thus, we have not only the vaso-motor, but the respiratory centre included in the thermal mechanics for increasing oxida- tion. When the loss in heat is rapid, as when cold is ex- cessive, the appetite, digestive and assimilative processes are increased, as has already been remarked — the latter from the additional amount of blood which is sent to the organs from the external parts — so that the whole mechanics for producing temperature work together in perfect concord and unity. But for its accomplishment, there must be a ther- mic centre for receiving and transmitting the sensory im- pressions produced by heat and cold, and for compelling the requisite vascular and respiratory movements suitable to the occasion. In other words, a special sense necessitates 366 CARBONIC ACID A FOOD FOR THE TISSUES. nutrition ; the one tending to dispersion, the other to accre- tion, or growth ; therefore representing opposite conditions. The circumstance which gives the clue here is the fact that the tissues are composed of compounds of carbon, floral as well as the animal tissues. Now, then, put these two facts to- gether, placing them side by side, for they are complementary and belong together, animal resting upon floral life, morever, is composite, floral structure and the principle in floral life pervading it, namely : 1. Carbonic acid is the principal source of floral structure. 2. The most active nutrition in animal life is coincident with the greatest accumulation of carbonic add in the blood-juices and tissues. It follows that the nutritive processes are similar in both, and that carbonic acid is the principal agent for producing nutrition in animals. Fur- thermore, it is the most soluble of all the organic compounds of carbon, therefore more readily diffused through the tissues, while little force is needed for decomposing it in the metabolic processes concerned in nutrition, so that no reason presents why this so-called waste product should not perform an enormous role in the nutritive processes, or the same as in the plant, the excess passing out through the lungs and secretory functions for maintaining a balance simply ; since the evolu- tion of force in the organism by producing carbonic acid would naturally create an excess which must be disposed of. In this manner nature works up old, effete structures in elaborating new tissues, as we have seen her do in the case of the lymph in the lymph-glands. Why not? No reason on earth, that 1 am aware of. And, being utilitarian to the last degree, we must conclude she works it in this manner with car- bonic acid. Last, but not least, the deeply suggestive fact that all plant and animal tissues are compounds of carbon, and that the only soluble condition of carbon fit for as- similation and in universal distribution over the earth and in living organisms is carbonic acid gas. And why interdict in the formative processes in animals ? Do not seek to rob nature of her most available means, nor place too wide an interval between kindred processes in plants and animals, seeing that they are only grades in development and forms of the same thing. CARBONIC ACID A FOOD FOR THE TISSUES. 367 And bear in mind, also, the fact, which is undeniable, that increase in nutrition corresponds with a slow circulation and increase of carbonic acid in the blood and tissues. This cir- cumstance has forcible illustration in mania apotu, in which sleep has at last been induced by full doses of morphia or hydrate of chloral, and though the sleepless and terrified patient is thus crushed, so to speak, into sleep at the peril of his life, with respiration as low as seven and eight per minute, breathing stertorous, the skin livid from ve- nous stasis in the systemic capillaries (as I have seen in a number of cases), death seeming to be impending ; yet he comes out of this condition, after from twelve to eighteen hours' sleep, actually convalescent, the mind clear and appetite voracious. And I cannot but think that the slow respiration and circu- lation, together with the great accumulation of carbonic acid in the system which must inevitably result, are the chief elements in the rapid reparative processes in these cases. The slowing of the circulation favoring the crystallizations in the nutritive processes, which the carbonic acid tends to increase ; at the same time, force is economized, since carbonic acid is necessarily formed in maintaining temperature and producing the various movements, requiring only that special additions should be made to it — nitrogen, hydrogen, etc. To me it seems most reasonable. ' ' Eat and sleep' ' is the advice in the nursery, and the child most gifted in this respect is decidedly the finest. iStock fatteners limit exercise as much as possible, restricting the animals to the smallest space, with the object of making them eat and sleep. The one reduces respiration and circu- lation ; the other increases the nutritive processes. And as age creeps on, and the habits become more and more sedentary, diminishing respiration and circulation in propor- tion, for the same reason it tends to the accumulation of fat. Concerning Carbonic Acid as a Stimulus. — The burning sensation in the throat and the feeling of warmth it produces in the stomach is a proof that carbonic acid acts as a stimulus to the digestive functions, and being exceedingly palatable, is much sought after. And since there would seem to be enough and to spare generated in the system, the appetite for it is very probably due to its action in this way. In impaired di- 308 CARBONIC ACID A STIMULUS TO DIGESTION. gestion it is highly beneficial ; and irritable stomachs respond more quickly to its action than to any other remedy, espe- cially when given in the form of "mineral water" and cham- pagne. But perhaps the strongest evidence of its stimulating properties is furnished by its action upon respiration, being the opposite of that produced by oxygen, which acts as a sedative to the respiratory centre. For example, if pure oxy- gen be respired, it gradually slows respiration, till finally apncea is induced. But when the oxygen is discontinued and carbonic acid substituted, respiration sets in again at once, growing more and more frequent ; respiration jumps up in leaps, becoming very rapid until the very body palpitates, so there can be no doubt that it is a respiratory stimulant, sub- serving useful purpose in this respect for maintaing a balance in respiration. And oxygen being a respiratory sedative, the necessity for a special stimulus to action would at once appear obvious, while this increase of the respiratory rhythms, which it produces when in excess, soon restores the dis- turbed equilibrium, and all runs on as before. In similar manner it also affects the heart, which beats tumultuously in impending asphyxia, expanding to its utmost limits before the fatal issue, from the action of this stimulus upon the nervous centres of the heart intrinsic, as well as extrinsic, affecting all of them, and the dilator equally with the contractor nerves. Indeed, the vaso-motor centre itself is in- cluded, as is fully evidenced in the wide arc of movement described by the so-called Traube's Curves (Fig. 41), which is undoubtedly produced by the increasing venosus of the blood. There can be no doubt, then, that carbonic acid is a stimulus to the respiratory, circulatory and digestive functions, inclu- sive of all the secretory processes. One of the most difficult circumstances, however, to account for occurs in connection with sleep, when respiration and circu- lation are slower than at any other time — this notwithstanding the fact of an increase of carbonic acid in the blood. This, however, could be accounted for by the fact that there is similar obtundity in all of the nervous centres ; sight, hear- ing, smelling, tasting, feeling — all are obtunded ; so that PHYSIOLOGY OF SLEEP. 369 unusual force must be applied to either one of them in order to increase the action : not produced by brain anaemia, either, only, in one sense, that there is diminished flow of arterial blood in the brain, since the veins and capillaries are liter- ally distended with venous blood, and the brain larger in consequence, occupying more room than in the waking con- dition ; which undoubtedly favors the nutritive processes, having this as the end. But, then, what induces it? The necessity for repair ! The arteries contract and diminish the lumen in the vessels, while the slowing of respiration causes the venous blood to dam back in the sinuses and cerebral veins, and so producing it, that the nutritive processes may restore what is lost by attrition in evolving force or for pro- ducing the movements in animal life. Very well ; we must accept that ! Cause of causes ! — show us the rest of it ! Fall- ing back upon the inevitable metamorphosis of force, we find that the arterial blood ebbs and flows in the brain according to whether sleep or animation is desirable, nutrition or force most needed in the organ and organism ; but there we stop at the brink of the abyss in Force itself, involving the universe of matter, for matter and force are forms of the same thing, undoubtedly. Concerning the Functions of Nitrogen Gas in the Animal Organism. — Briefly, an amount of nitrogen disappears in res- piration to reappear in arterial blood, but again to disappear in the tissues, since the venous contains less than arterial blood, the relative proportion being 1.30 to 1.60 in the 100. But when we come to the gases contained in its several portions of the intestinal canal, this phenomenon has ready explanation, constituting a necessary part of the mechanics in the diges- tive and absorptive processes in the organs, or means to ends, the secretion of the gas being essential to the maintenance of a balance in pressure within the canal, which, of course, must have adjustment with the exigencies in the functions, and as a consequence must vary in the several portions. Thus, in a series of experiments instituted upon executed criminals, by Majendie and Chevreul, the following gases were found to be present in the stomach and intestines : 370 FUNCTIONS OF NITKOGFJ5T GAS. Gases contained in the Stomach. Oxygen 11.00 Carbonic acid 14.00 Pure hydrogen 3.55 Nitrogen 71.45 100.00 Thus, casting our eye over the chemical analyses, we find that oxygen in the proportion of 11 parts in the 100 presents for the first and last time in the stomach ; hence, is very probably carried in with the boluses and liquids, whence it is absorbed and carried to the liver, to be consumed in the metabolic pro- cesses ; a remnant, as it were, of the primitive mode of respi- ration. It would also account for a portion of the nitrogen and carbonic acid, but not all of them, leaving a large residuum still unaccounted for, save by the secretory function in the gastric capillaries. This circumstance is fully proven in the cases of the small and large intestines, notably : Oases contained in the Small Intestine. First Second criminal. criminal. Carbonicacid 24.39 40.00 Pure hydrogen 55.53 51.15 Nitrogen 20.08 8.85 100.00 Third criminal. 25.00 8.40 66.60 100.00 100.00 Gases contained in the Large Intestine. First Second criminal. criminal. Carbonic acid 43.50 70.00 Carbureted hydrogen and traces of sulphureted hydrogen 5.47 Pure hydrogen and carbureted hydrogen 11.60 Pure hydrogen Carbureted hydrogen .... Nitrogen : 51.03 18.40 Third criminal. Caecum. 12.50 Third criminal. Rectum. 42.86 7.50 12.50 67.50 11.18 45.96 100.00 100.00 100.00 100.00 It will be seen from the above exhibit that carbonic acid and nitrogen are the principal gases in the small and large in- testines, as well as in the stomach; in the third criminal the total amount aggregating as much as 91 and 88. ^2 respectively for the small and large intestines, the remainder being made up of the hydrogen gases, principally pure hydrogen. The large amount of this gas in the small intestines of the FUNCTIONS OF NITROGEN GiS. 371 first and second criminals is difficult of explanation ; but as hydrogen is evolved in the nutritive processes in the plant, we may infer that the epithelial cells are the principal source. But there can be no doubt respecting the source of the remarkable quantity of carbonic acid and nitrogen in the large intestine of all the criminals, being respectively 94.53. 88.40, 80 and 88.82 in the rectum of the third criminal ; the quantities of the two gases varying. All we seek to show by this circumstance is the power on the part of the blood-capillaries to secrete these gases out of the blood in the measure of the physiological requirements in the organs in the exigencies in the functions ; and since the whole matter relates to pressure, the relative amount, of course, would have to be determined by the quantities of the other gases already in the intestines or evolved by the chemical and secretory processes in the organs ; and as this must necessarily vary from time to time, it would imply a corresponding power of absorbing them when in excess of the demand ; hence the circumstance of the excess in expiration daring digestion, as has already been mentioned. Finally, the power on the part ol the intestines to secrete the gases is proven to demonstration by physiological experi- ment upon the gut (p. 203), while respiration itself is based upon this power in the blood-vessels to secrete and absorb the gases ; otherwise carbonic acid could not be excreted nor oxygen and nitrogen be absorbed. In Reference to the Odor of F&cal Matter. — In respect to the peculiar odor of faecal matter, the chemical experi- ments of Professor Liebig afford the clue. For example, he ascertained that if albuminous compounds are subjected to heat with solid hydrate of potash, and the heat be continued until the greater portion or the whole of the nitrogen is dis- sipated as ammonia, and free hydrogen begins to escape, the residue, when supersaturated with dilute sulphuric acid, and distilled, yields a liquid containing acetic and butyric acid, and possessing in a very intense degree the peculiar and char- acteristic odor of human fasces; the odor varying accord- ing to the substance used, in this way accounting for all varieties of faecal smell. Now, then, in view of the fact that 372 PHYSIOLOGY OF FJEOAL ODOR. the chemical reactions in living organisms without the agency of heat per se, but by the action of electrical force, aided by the mutual affinities in the molecules, and that oxygen and lrydrogen in the form of water have their bond of union Droken in this manner, notwithstanding the prodigious force it involves, the explanation of the chemical reactions detailed by Professor Liebigfor evolving fa9cal odor without involving any harm to the tissues, would appear natural enough, and not at all extraordinary. Concerning the Genesis and Functions of the Gases in the Air -Bladders of the Fishes. — This function in the blood- vessels for carrying the gases to and from the internal parts for subserving important mechanical uses in connection with the special functions in the organs has forcible illustration in the air-bladders of the fishes, in which it subserves a dual function, notably : 1. For buoying them in the media, thereby powerfully assisting the action of the fins, enabling the animal to ascend or descend with the utmost ease and celerity by simply expanding and contracting the air-bladders and body-walls, using the fins and tail, of course, for assisting the action 2. For transmitting sonorous vibrations through the body- walls upon the ossicles and otolites of the auditory apparatus (Fig. 147, o, m, I, d). As will be seen, the anterior portions of the bladder (p) fit accurately against the expanded base of the large ossicle (o), this against the ossicles m and I, whence the force is transmitted upon the delicate extremities of the acoustic nerve, which are expanded upon the chamber of the vestibule Id j means of the two subspherical "atria" on the body of the atlas, close to the foramen magnum, and the endolymph which fills both atria and the common sinus. The sonorous vibrations thus communicated to the suspended otolites (d) are made to beat upon the nervous filaments of the auditory nerve in the chamber of the vestibule containing the otolites upon the lining membrane of which the nerves are expanded. In the herring, the tubular prolongation of the fore part of the bladder (Fig. 148, Jc) advances to the basi-occipital and bifurcates ; each branch penetrates the side of the base of the skull, again bifurcates, and terminates in two blind sacs, which FUNCTIONS OF THE GASES IN FISH-BLADDEKS. 373 374 FUNCTIONS OF THE GASES IN FISH-BLADDERS. are in contact with similar csecal processes of the labyrinth (Owen). In this manner, then, the gases contained in the air-bladders of the fishes subserve two important functions : one for over- coming body-inertia, the other for transmitting sonorous undu- lations upon the auditory nerves ; while in the mammalia, we have seen that air is utilized in the intestines for increasing the digestive and absorptive processes by means of the force trans- mitted from the walls of the gut and the muscular envelope of the body upon the aliment ; or, -in other words, for overcoming inertia in the nutritive and force-producing elements and speed- ing them into the vascular channels, and, in very truth, is the stepping-stone in higher development or mammalian evolution. And that the blood is the source of the gases in the air- bladders of the fishes is manifest, from the following facts, notably : 1. The air-bladder is the nascent condition of the lungs, into which it is subsequently developed ; hence the power to excrete and absorb the gases inheres in the organ. 2. It would account for the absence of the air-duct in vast numbers of fishes, notably, Acanthopteri, e. g., perch, mullet, mackerel, angler, etc.; Anacanthini, e. g., cod! plaice, etc. ; Plectognathi, Lophobranchi. And there being no air-duct in these fishes, it follows that the blood must be the source of the gases contained in the air-bladder, and not the intestinal canal, which serves as an outlet in the other fishes for rapid discharge of the gases, in order to obviate strain when moving from the deep to the surface waters, where sudden expansion is inevita- ble. 3. It would account for the special gases in the air-bladders of the fishes, which consist, in most fresh-water fishes, of nitro- gen and a very small quantity of oxygen, with a trace of car- bonic acid gas ; while in the air-bladder of sea-fishes, espe- cially those which frequent great depths, oxygen predominates, as much as 1-7 in the 100 in volume being reported by Biot in some of the deep-sea Mediterranean fishes ; the rest nitrogen, with a trace of carbonic acid. In these cases, the air-bladders function as special reservoirs for oxygen to subserve respira- tory purposes in the depths where the gas does not circulate so freely ; finally, no hydrogen has ever been detected in the GENESIS OF THE GASES IN FISH-BLADDEKS. 375 air-bladders of fishes, which also shows the gases are not de- rived from the intestinal canal. 4 Lastly, we have to mention the peculiarities that obtain in the capillary network of the air-bladders as the special pro- vision for excreting and absorbing the gases, while the branchiae form an open portal for their ingress and egress to the blood vessels. The principal seat of the vascular ramifications in the air-bladder, like that in a true lung, is the mucous lining mem- brane, but there is variety in the terminal divisions of the arteries. In the carp, for example, they terminate in fan-like tufts over almost every part of the inner surface. In the pike they are larger and more localized, but without any special aggregation of the capillaries to form a " vaso-ganglion" ; but in the perch and cod the capillaries are aggregated so as to form red, gland-like bodies (Fig. 149) ; the capillaries reuniting into larger vessels, which again ramify around the gland-like body ; the rest of the inner surface of the air-bladder retains the ordinary simple capillary system. It will be seen that the afferent and efferent vessels to these bodies form vascular loops, which are covered by a layer of vessels and epithelium (a, a). In addition to this, however, are a number of peculiarly arranged, elongated corpuscles, which depend in two rows from each vascular branch, and are bound together by a loose cellular tissue ; the corpuscles are beset with fine villiform processes. The blood returns from the vaso-ganglions by small veins, which rarely accompany — more commonly cross — the arteries (Owen), and is certainly strong corroborative proof of this function in the arterial capillaries for excreting the gases. In the eel and conger, the two chief ganglions, which are situated at the sides of the opening of the air-duct, consist of both arterioles and venules ; they consist of straight parallel capillaries (Fig. 150) ; their efferent trunks do not ramify in the immediate margin of the vaso-ganglion from which they issue, as in the vaso-ganglions of the cod, burbot, acerine and perch, but run for some distance before they again branch to form the common capillary system of the lining membrane of the air-bladder (Owen). This aggregation of capillaries in arterial and venous retia is undoubtedly favorable for rapid secretion and absorption of 376 GKNESIS OF THE GAS'S IN FISH-BLADDEKS. the gases ; indeed, not gases only, but liquids as well, since the Malpighian glomeruli are homologous, formed by the terminal branches of the renal artery, and from which an afferent vessel is given off to be distributed to the urinary tubules (Fig. 117, va, gl, ve). And they also occur in other Fig. 148. — Abdominal Viscera, with Air-Bladder (k) in situ, Herring (reduced).— Brandt and Ratzeburg. . Medizinische Zoologie. 4to. 1833. a, CEsophagus ; b, stomach ; c, pylorus ; d, appendices pyloricae ; e, e, intestine ; /, anus ; 7i, h, testes ; i, genital ducts ; k, air-bladder ; I, pneumatic duct. Fig. 149. Superficial and Looped Vessels of the Vaso-Ganglion of the Air-Bladder, Cod.— Dr. Wdliams. Fig. 150.— Parallel Vessels of the Vaso-Ganglion of the Air-Bladder, Eel.— Dr. Williams. localities — notably, in the arteries of the mesentery contiguous to the intestines — and are common in the limbs of the sloth, the axillary and iliac arteries in these slow-moving animals, just before entering the limbs, suddenly dividing into numer- ous small channels, which again unite into one trunk before the members are given off ; in these cases serving as reser- voirs for storing arterial blood for evolving the local actions OFFICE OF RhTE MIR A BILE. 377 concerned in digestion, and for producing the muscular force for sustaining the weight of the animal suspended by its limbs. But this is seen upon a prodigious scale in the enormous arte- rial plexuses in Cetacea, wherein a vast quantity of arterial blood may be accumulated for supplying the wants of the animal during prolonged periods of submersion. For exam- ple, the intercostal arteries divide into a vast number of branches, which run in a serpentine course between the pleura and the ribs, and penetrate the intercostal muscles, every- where lining the walls of the thorax ; moreover, they pass in between the ribs near their articulation, and anastomose extensively with each other. And in like manner the central nervous system is embossed by dense arterial plexuses ; more especially the medulla oblongata, where a thick substance is formed by their ramiii cations and convolutions — aretemira- bile on a prodigious scale for sustaining the functions in the great nervous centre for the organism during prolonged periods of submergence, Nature in this manner storing oxygen for the purpose. Mirabile ! CHAPTER XVII. FACTS IN DEVELOPMENT, SHOWING THE RELATIONS WniCH THE HE^RT SUSTAINS TO THE MECHANICS OF CIRCULA- TION. Principle in Cardiac Evolution— Respiration and Circulation in "Worms — The First Indi- cations of a Heart Found in Connection with the Localization of the Respiratory Apparatus, notably Terebella — Facts Revealed in Decapods — Ditto Fishes — Ditto Reptiles — Differentiation of the Left Cardiac Chambers with Air-Breathers, First the Auricle, then Ventricle — Enormous Development of the Muscles in the Heart in Tortoise — Reasons Therefor — Perfection of the Interventricular Septum in Crocodilia, but Leaving a Passage between the Left and Right Sides of the Heart, so as to Allow Reflux during Submergence — Reasons Therefor — The Changes with Progress in Development till the Birds are Reached, in which Cardiac Develop- ment is Complete — The Heart always in Intimate Connection with the Oxygenating Apparatus, since it Relates to the Evolution of Force in the Organism. In tracing cardiac development, we must begin, of course, with the principle upon which development, itself, is based, when all the phenomena appertaining to it have ready explana- tion ; otherwise are inexplicable. Since all the activities, in- clusive of the movements in the viscera, blood-vessels, and heart — indeed, every variety of motion in the organism — is evolved from force which is generated by the combinations effected with oxygen, it follows that the importation and circulation of oxygen is fundamental in the organism ; and the blood being the medium for receiving and transmitting it to the tissues, the comprehensive arrangements that obtain for pumping it through the lungs and tissues in the measure of the physiological requirements will be readily apprehended ; also, why the respiratory and circulatory apparatus should be a connected movement, otherwise the scheme would fail The intimate relations which the heart sustains to the respiratory apparatus, then, are to be explained by this principle in the mechanics ; while the changes of form which it undergoes with progress in development, are due to the peculiarities PULSATION FIEST ITST THE VESSELS. 379 which obtain in the respiratory apparatus, which impress themselves upon the heart as the local reservoir and force- pump, for receiving and transmitting the blood to and from these organs, together with the necessity for a gradual and more and more complete separation of the arterialrzed blood, upon which progress in development depends, since this is essential for the production of the relative phenomena. In fine, the vascular system is molded, so to speak, to the respiratory apparatus, undergoing special modifications in cor- respondence with the changes which have taken place in the stage in development, while the differentiation of a heart or central force-pump in connection with the oxygenating apparatus is for the purpose of increasing circulation in it in correspondence with the amount of force which is expended in the organism, the one involving the other. And viewed from this stand-point and the law for increasing circulation — namely, by rhythmical changes in pressure — the special role in the heart and the mechanical principle it involves, inclusive of the nerves for coordinating it with respiration, is at once made intelligible, together with all the relative phenomena appertaining to it ; otherwise inexplicable. Thanks to numerous workers in the field and the opulence of material, the labor involved in this inquiry is enormously diminished, requiring only to be care- fully collated and systematically arranged. For this purpose, we begin with the earliest stages in cardiac development ; notably, worms, in which a highly complex circulation is car- ried on in the absence of a heart for producing it, following thence through the successive stages in cardiac evolution to the warm-blooded animals, in which cardiac development is complete. And we begin with the worms, for the reason that pulsation is first visible in the vessels ; hence, is not necessarily dependent upon the heart or synonymous with its action, since it exists long before a heart comes into the scheme ; moreover, is not limited to the blood- vascular system, for it is met with in the veins and lymphatics of amphibia and occurs in the lacteals of warm-blooded animals. At the same time, how- ever, in the worms local dilatations occur in the vessels corre- sponding with the branchial and air-vesicles, thus early indi- cating the principle in the blood- vascular system for increasing 380 GROUND PLAN OF THE CIRCULATION. circulation in the lungs by the differentiation of a heart for assisting the action. Briefly summarized, the ground plan of the animal circu- lation commences by the formation of several longitudinal vessels (three or more), extending the length of the body of the worms, first visible in Nemertina (Gegenbaur) ; a median dorsal, which lies above the enteron and is pulsatile, and two Fig. 151. — Ground Plan of the Vascular System in Nemertina. — Gegenbaur. d, Dorsal longitudinal trunk ; I, I, lateral longitudinal vessels. The arrows indicate the direc- tion of the stream. lateral vessels, one upon either side (Fig. 151, d, I, Z), which are veins that deliver the blood into the median dorsal artery, with which they connect at the terminal ends and by transverse vessels ; whence it is passed forward by successive expansions and contractions in the dorsal vessel, the lateral branches given off at regular intervals by this great trunk conveying it NO HEART IN" THK WORMS. 3 SI to the muscular parietes for generating force, and to the cuta- neous capillaries for oxygenation, to be re-collected in the cor- responding branches of the lateral veins, which also collect the blood in the viscera ; while a portion continues on to the cephalic end and the vascular loop or loops, as the case may be, which encompass the oesophagus. The simplest condition of the vascular system is seen in those which have no per- ceptible respiratory organs, oxygenation being effected through the thin integument and subjacent capillary network — e. g., nais and planar ia. In the transparent body of erpobdella vulgaris, two median vessels, a dorsal and a ventral vessel, are discernible, which, by their waves of pulsation, convey the blood into numerous lateral branches (Fig. 152, 5), the capil- Fig. 153. Fig. 153. Fig. 152.— Diagrammatic Representation of the Vascular System in Erpobdella Vulgaris, showing the numerous lateral branches given off by the median ventral vein (b), and which anastomose with corresponding branches from the two lateral venous trunks (c, c), and dorsal artery (a). Fig. 153. — Vascular System of Lumbricus Terrestris (anterior portion), a, a, Median ventral vein ; 6, b, great dorsal artery ; c, c, sacculated arches. The arrows show direction of the stream. — Grant. laries of which are continuous with those of the two great returning veins (c, c), extending backward along the sides of the body (Morren). In annelides, it is pretty much the same ; the venous blood of these animals is commonly returned from the system to the posterior extremity of the dorsal artery by a median ventral vein, or by two inferior lateral veins ; but considerable modifications are induced in higher genera by development of respiratory organs in the form of external cephalic or dorsal branchiae or internal air- vesicles. In nereis cuprea, the long dorsal artery appears slightly dilated in each 382 NO HEART IN THE WORMS. segment of the body, and receives or gives off the branchial vessels from the arterial arches which encompass the oesopha- gus (Grant) In other species, the branchial vessels are given off to these organs from each side of the dorsal artery in its whole course forward (Fig. 153, d, b, b), and the fifteen pairs of ramose branchiae presenting in arenicola induce as many corre- sponding modifications in the vascular system of these ani- mals ; while small pulsating vesicles are generally perceptible on the lateral systemic branches of the dorsal artery. In the earth-worm {Jumbricus terrestris). the direction of the internal currents, owing to the greater transparency of the body, is more perceptible than in the more opaque body of the leech, where it is necessary to examine this part in very young individuals, and where the currents have appeared often to change their direction through the vascular trunks. Successive waves of contraction are distinctly seen in the earth-worm, extending from behind forward along the wide dorsal vessel ; and by removing the integuments and pressing this artery between the forceps, it becomes empty in front and turgid behind. It appears to receive the arterialized blood from the air-vesicles, and sends off numerous lateral branches in its course, especially to the alimentary canal and the geni- tal organs. The venous blood is collected from the viscera chiefly by the great median subgastric or epineural vein, extending backward between the digestive canal and the nervous columns; and this vessel appears to send off branches to the numerous minute respiratory vesicles. A small inferior median vessel or hyponeural vein is also perceived, extending along the under surface of the nervous chords, and an accompanying lateral branch is seen, as usual, on both sides of the same columns. Anterior to the commencement of the stomach, the great dorsal artery (Fig. 153, b, b) communicates with the median subgastric vein (a, a) by five or more pairs of lateral, wide, sac- culated arches (c, d), which embrace the oesophagus, as the corresponding vascular arches which connect these t wo vessels in other annelides and in the entomoid classes. According to Dr. Williams, the following is the plan of circulation in earth-worms (Fig. 154) : The circulation is very complicate. NO HEART IN THE LEECH. 383 They respire through the cutaneous surface, which is occu- pied by a dense capillary plexus ; also through the alimentary canal, which is similarly supplied, and which undoubtedly functions as a respiratory as well as digestive organ. It is also claimed that the stratum of viscid matter in which they are always enveloped is remarkably endowed with the property of absorbing and dissolving atmospheric air (Jones). Eig. 154. — Diagram. Illustrative of the Circulatory Apparatus in the Leech (Hirudo Medici >. alis). — After Dr. Williams, a, Great dorsal vessel ; c, ventral vessel ; d, d, intercommunicating vessels between dorsal and ventral trunks ; e, e, lateral abdomi- nal trunks ; g, vessels distributed over the cascal appendages to the stomach. From the equal development of the great vascular trunks and the numerous transverse anastomoses, it is easy to per- ceive how the circulation in these animals can, by the closing of the divided ends of the vessels, become accommodated to extensive mutilations, and proceed without interruption in a few segments detached from the trunk. Some of the simpler forms of annelides, e. g., styluria, are thus enabled to ex- 384 NO HEART IN- THE LEECH. tend their means of propagation by the spontaneous transverse fission of the body. But the leech, perhaps, presents the most complicate vascular arrangements of any of the annelides, though the ground plan of the circulation is fundamentally the same as in all the other worms and entomoid classes, consisting of a number of longi- tudinal trunks with the median dorsal and ventral occupying the old positions, the blood passing to the caudal end through the one and the cephalic in the other, while the lateral branches pass into the segments and effect circulation transversely. The dorsal is recipient of arterialized blood, which it dis- tributes to the organs (but venous blood also flowing into it by the anastomosing branches, especially with the median ventral), while the ventral functions as the systemic venous trunk, from which the blood is sent to the respiratory vesicles. In addition to the dorsal and ventral trunks, however, are two large lateral trunks, one on each side (Fig. 155, e, e), which, according to M. Duges, * are appropriated to the respiratory system of lateral sacculi, of which there are seventeen pairs symmetrically disposed along the sides of the body, with thin spiracles opening along the ventral surface. That the movement of the blood in the lateral or respi- ratory system of vessels is quite distinct from that which is accomplished in the dorsal and ventral or systemic trunks ; sometimes it passes down one of these vessels from the head toward the tail, and in an opposite direction on the other side of the body ; but in a short time the movement of the cur- rents will be seen to become completely reversed, so that an undulatory motion, rather than a complete circulation, is kept up. By this action of the lateral canals the blood is made perpetually to pass and repass the respiratory sacculi ; and, opposite to each of these, branches are given off which form so many independent vascular circles, representing very closely the minor or pulmonary circulation of higher animals. Finally, the rich supply of arterialized blood sent to the lateral caeca of the stomachal cavity for promoting the secre- tory processes in these organs in connection with digestion, has * Ann. des Sci. Nat., vol. xv. NO HEAET I INT THE LEECH. 385 forcible illustration in the beautiful arborescent arrangement of the vessels in the walls, with their footstalks connecting immediately with the dorsal artery (Fig. 155, g, a). The fol- lowing illustration (Pig. 156) will give some idea of the rela- tions the csecal pouches ( 7c) sustain to the stomachal cavity and respiratory vesicles ; the stomach itself occupying about two-thirds of the visceral cavity, is divided by septa or dia- phragms into nine or ten compartments, but communicating Fig. 155.— Diagram Illustrative of the Circulation in the Leech. — Dr. Williams, a, Great dorsal vessel ; c, ventral vessel ; d, d, intercommunicating vessels between dorsal and ventral trunks ; e, e, lateral abdominal trunks ; g, vessels distributed over the caecal appendages to the stomach ; /, /, /, loop-shaped organs to the respira- tory vesicles ; h, h, lateral branches to respiratory vesicles. freely with each other, and in each of which are two openings communicating with the lateral caeca. Up to this stage in development, then, in which a very com- plex circulation is seen to exist, no heart presents, but the ves- sels themselves producing it, inclusive, of course, of the action of the polar forces. Unless, forsooth, the whole dorsal vessel, running the length of the body, inclusive of the lateral branches, be considered as such, which is perfectly absurd — the outcome, in fact, of the misleading and erroneous concep- tion that the animal circulation is based upon the heart, which 3SG STOMACH AND C^ECA IN THE LEECH. is a means for increasing it simply, and "putting the cart be- fore the horse," by reversing the order in nature. Further- more, it would leave unexplained the action in the other ves- sels ; consequently, the principle is \\ rong. And as the organ re- lates to the production of force by increasing circulation in the Fig. 156.— Digestive Organs of the Leech (Hirudo Medicinalis). — Jones, b, Pharynx ; hr i, interior of stomachal cavity, exhibiting the diaphragms, with the lateral openings in the caecal appendages (k) ; g, first pair of stomachal caeca ; d, last pair, extending backward on each side of the intestine (e), which opens on the dorsal surface close to the terminal sucker. respiratory organs, the absence of a heart in the circulatory sys- tem of the annelid es is readily accounted for by the diffused res- piration which obtains here, for in every part of the circumfer- ence of each ring the blood is being arterialized as it is being ren- dered venous ; hence, no heart is developed, the action in the dorsal artery with the lateral vessels extending into the capil- lary plexuses of the skin, respiratory-vesicles, or branchiae, as NO HEART IN ARENICOLA. 387 the case may be, being sufficient for the purpose and subserv- ing the functions of a heart. But this latter circumstance is made more conspicuous in arenicola (Fig. 157), in which the circulation is simplified. And this beautiful diagram, by the distinguished anatomist and naturalist at Heidelberg, will serve to give a distinct mental picture of the adaptive changes in the vascular system to the form of the respiratory apparatus and the principle that obtains in the mechanics for increasing circulation in it commensurate with the force which is ex- pended in the activities. As will be seen, the branchial vessels (b, b) are connected directly with the great dorsal and ventral trunks (d, v) the blood from the latter passing into the Fig. 157. — Diagrammatic Transverse Section through the Hinder Half of the Body of Arenicola, to show the arrangement of the vessels. — Gegenbaur. D, dorsal ; V, ventral side ; n, ventral medulla ; i, enteric cavity ; or, branchiae ; v, ventral vascu- lar trunk ; ab, branchial vessels ; d, dorsal vascular trunk ; h, branch surrounding the enteric canal ; v', visceral ventral vessel. branchia ibr) by means of the afferent vessel (a), thence to the dorsal artery through the efferent vessel (b), one upon either side corresponding with the branchiae ; hence, any ex- pansile action m the branchiae or vibratory motion tending to increase circulation in the plexuses would necessarily deter- mine the venous blood in this direction, while the pumping ac- tion in the dorsal vessel should serve for aspirating the plexuses and propelling it through the system ; since the diastoles pro- duce a suction-force and the systoles a driving force upon the blood. And though reflux is inevitable, by reason of the absence of valves, still this is limited, from the fact that the blood which is withdrawn from the plexuses by the diastoles is instantane- ously supplied by the venous blood flowing into them, filling them before the succeeding systole sets in, or nearly so ; so that only a small amount of reflux is possible. But this mechanics 388 NO HEART IN ARENICOLA. would not answer when a heart comes in the scheme, for the reason that the force in the latter would tend to rupture the capillaries from the strain it should occasion ; hence the dif- ferentiation of valves for obviating reflux. In addition to these vessels, however, we have now to notice another arrange- ment of equal importance, notably the one relating to the intestinal canal, since this is the gateway of the nutrient and force-producing elements. Here, for example, we have two lateral vessels (h) that embrace the intestinal canal (/) and con- nect with the visceral ventral vessel (vr) and the delicate plex- uses in the visceral parietes on the one hand, and the dorsal vessel (d) upon the other ; and bearing in mind the mechanics in the portal circulation, is it not apparent that striking cor- respondence subsists between them ; nay, that here we have indeed the very thing itself in its nascent stage ? Notably, the visceral blood is collected by special veins and delivered in the systemic current (d), passing thence into the respiratory apparatus ibr) by the vessels (bb), the pumping action in the dorsal vessel being the analogue of that in the heart, while the contractions in the external muscular envelope, by in- creasing pressure in the viscera, should serve for expediting the action ; not to mention the suction-force exerted by the branchiae themselves, which, of course, affects the blood in these vessels in similar manner as in the corresponding ves- sels to the ventral venous trunk (a, n) ; and since the animal is in constant motion, the vermicular movements should in- crease the visceral circulation and respiration correspondingly. It is not fanciful, since there is definite arrangement in the parts, and there is absolute necessity for such provision, in order to maintain a balance in the organism. Now, then, looking from this diffused respiration in areni- cola to the localized respiration in terebella, where the branchiae project from the occiput (Fig. 158, &, &), the effect upon cardiac development is at once made apparent. For example, the great dorsal vessel (m) is now greatly reduced in size by reason of the disappearance of the lateral branchiae, while the vascular oesophageal collar (n), which receives all the blood from the intestinal system, is increased in size cor- respondingly and functions as an auricle to the elongated fusi- FIRST EVIDENCE OF A HEART IN" TK RE BELL A. :^89 form heart (I) lying upon the oesophagus (e) in immediate relation with the respiratory organs (k, k), this portion of the great dorsal artery taking on increased development in correspondence with the branchiae, the other shrinking in size, responsive to the changes in the respiratory organs. Fig. 158.— Vascular System of Terebella.— Milne-Edwards. Showing the earliest indi- cations in cardiac development (I), and the relations it sustains to the respiratory- organs (k, k). Briefly, the haemal mechanics is as follows : The fusi- form heart (d), which is but slightly attached to the struct- ures on which it rests, and suspended, as it were, in the fluids of the peritoneal cavity, sends off at the anterior end three lateral symmetrical branches (Fig. 159, a, d) to the branchiae, the reduced continuation of the original trunk break- 390 PLAN OF CIRCULATION IN TEREBELLA. irig up into minute vessels to the tentacles, in the hollow axes of which each terminates in an efferent vessel, and which are surrounded by the peritoneal fluid, which penetrates to the remotest ends of these exquisite organs. But the branchiae are Fig. 159. — Plan of the Circulation in Terebella. — Dr. Williams, a, Elongated fusiform heart ; 6, vascular oesophageal collar, which receives all the blood from the intes- tinal system (auricular) ; rf, the three pairs of branchial arteries to a corresponding number of branchiae ; c', three pairs of branchial veins corresponding with the arterial conveying the aerated blood into the longitudinal systemic trunk (c, c) to be distributed to the intestines and body-territories, three pairs of lateral branches crossing the oesophageal collar (b) to connect with the great dorsal vessel ; /, frame- work of longitudinal and transverse vessels, embracing the alimentary canal, as in all annelides. the principal organs of respiration, the three pairs of large lateral arterial branches to which terminate in a correspond- ing number of efferent vessels (c' ) that converge in the great ventral trunk () — but taking the shortest and most direct route to reach the heart and central nervous system, the life of the embryo depending upon it. The follow- ing illustration will serve for impressing the matter. The arrows indicate the course of the blood stream. Only, the diagram is misleading in several essential points, which I am compelled to notice, but it grieves me to have it to do ; nota- bly : 1. The ductus arteriosus (6) is nearly as large as the umbilical vein itself (3), creating the impression that the greater portion of the umbilical blood continues directly on into the vena cava, whereas fully three-fourths is diverted into the liver ; therefore tending to misdirection, doing harm to the medical pupil, and retarding physiological progress as well. 2. The portal vein (7) is too large in propor- tion— is larger than the combined umbilical and portal streams (4, 4), and is made to appear as though it debouches in the umbilical vein with the right hepatic vein, thence through the ductus venosus into the lower cava ; whereas, it blends with the umbilical stream at the portal gate, divides and subdivides in the liver parenchyma as an artery, the um- bilical and the portal blood forming the common stream, 442 OCCASION FOR A DUCTUS VENOSUS. O Q u u Fig. 186. — Diagram of the Fatal Circulation. 1, The umbilical cord, consisting of the umbilical vein and two umbilical arteries, proceeding from the placenta (2) ; 3, the umbilical vein dividing into three branches ; two (4, 4) to be distributed to the liver, and one (5) , the ductus venosus, which enters the inferior vena cava (6) ; 7, the portal vein, returning the blood from the intestines, and uniting with the right hepatic branch ; 8, the right auricle ; the course of the blood is denoted by the arrow proceeding from 8 to 9, the left auricle ; 10, the left ventricle ; the blood following the arrow to the arch of the aorta (11), to be distributed through the branches given oS: by the arch to the head and upper extremities. The arrows 12 and 13 represent the return of the blood from the head and upper extremities through the jugular and subclavian veins, to the superior vena cava (14), to the right auricle (8), and in the course oi the arrow through the right ventricle (15), to the pulmonary artery (16) ; 17, the du 'tus arteriosus, which appears to be a proper continuation of the pulmonary artery ; the offsets at each side are the right and left pulmonary arteries cut off. The ductus arteriosus joins the descending aorta (18, 18), which divides into the common iliacs, and these into the internal iliacs, which become the umbilical arteries (19), and return the blood along the umbilical cord to the placenta, and the external iliacs (20), which are continued into the lower extremities. The arrows at the termi- nation of these vessels mark the return of the venous blood by the veins to the inferior OCCASION FOR A DUCTUS VEI^OSUS. 443 while the ductus venosus conveys the unmixed arterial "blood to the lower cava. But the principal objection, that the hepatic blood is not delivered into the vena cava at all, the hepatic veins not being represented by any circum- stance in the diagram. And to call this "the foetal circula- tion," with fully three-fourths of the blood cut off, is simply absurd. It is like knocking the bottom out of the boat to give it a neat appearance ; or, rather, constructing a boat with- out a " bottom," everything taut and ship-shape but the bottom, which is absent. If physiology is to advance, it will uever be over that line. The anxiety to show the wonderful double spiral twist in the blood stream within the foetal heart, by means of which the blood from the lower cava is transferred to the ascending aorta (8, 9,) through the foramen ovale, etc., and that from the upper to the descending aorta through the ductus venosus (16, 17), I conceive to be the explanation of the great blunder. What is needed, above all things, are the anatomical facts , and the special law which applies in the case ; and by regarding anatomy from the stand-point in the organic laws, physiology is placed upon firm ground and the dismal morass made fertile soil. CHAPTER XVIII. DUALISM IX MUSCLES AND NERVOUS FORCE. Nature of Vital Force — Principle in Expansion and Contraction — Molecular Changes in the Cell-Contents Involved in both Movements ; Illustrated by the Action in Pro- toplasm and in Muscle Cells during Contraction, as Seen in the Field of the Polar- izing Microscope — Dualism in Nervous Force Essential to the Production of both Movements — Extraordinary Hardness Produced in the Muscles by Nervous Fore© — Explanation Therefor — Hardness a Measure of Work — Mode of Demonstrating This Circumstance — An Easy Method of Proving Dualism in Muscles, and by Implication Xervous Force — Lessons Taught by the Phenomena in the Leech — Ditto, Tongue of the Frog — Ditto, Tortoise ; the Action in the Head, Neck and Tail Demonstrating Dualism in Muscles and Nervous Force — Ditto, Conchifera, for Opening and Clos- ing the Valves ; Together with Physiological Experiment Demonstrating the Cir- cumstance— Ditto, Inferior Maxilla in the Dog, showing the Masseter and Tem- poralis Muscles are Operated in the Same Way, the Mouth being Opened and Closed by Means of Expansion and Contraction in these Muscles — Physiological Experiment upon the Nerves to the Ciliary Ganglion Proving Dualism in Nervous Force upon the Nerves — The Circumstance Applied to the Oral Muscles and the Action in all the Sphincters, all of Them in Common Possessing Circular and Radiating Muscles, the Same as the Iris — Action in Erectile Tissue Readily Ex- plained ; Elucidated by the Action in the Tongue of the Chameleon, Penis, etc. — The Special Role in Nerves with Respect to Nervous Currents, Nervous Centres, Separators and Delimitators of Electrical Fluids Generated in the Tissues and Carried to the Centres for this Purpose — Reasons Therefor. In order to complete the argument, it will now be necessary to enter a little more fully into the mechanics for producing expansion and contraction in the tissues and organs, bringing into prominence the principle in animal movement, making this also clear and easily understood. Nor will it be necessary to unduly expand the argument, exceeding the limits allotted to this work, since we are dealing with principles, and a few illustrative cases will be sufficient for the purpose, at the same time maintaining continuity throughout, the whole resting upon the action in the polar forces intensified by electrical currents. Thus, we have seen (p. 6) that there is but one means known to science for suspending matter in space and producing movements in it contrary to gravitation, which is NATURE OF VITAL FORCE. 445 by the action of electricity and polar forces which, electricity serves to intensify, as illustrated by the rubbed glass and silver leaflet (Fig. 2). Vital Force ! Never mind about vital force ; one thing at a time ; vital force has had its day. What we positively know is, that heat and electricity produce move- ments in matter contrary to gravitation, and that polar force is the guiding principle, serving also to lock the molecules in the positions which they occupy in the structures, animate or in- animate, as the case may be ; at the same time maintaining mobility so as to produce the requisite changes among the molecules involved in the varied animal movements, having its acme in the muscular and nervous structures, while this in turn has its culminating point in warm-blooded animals in which body -temperature is highest. Accepting this, which is incontrovertible, all we have to do, then, is to make inspec- tion of the special molecular physics, since it is by means of the changes effected in the relative positions of the mole- cules in the cell-contents that the changes of form are pro- duced in the cells and in the mass composing the muscles, etc., whereby the movements, voluntary and involuntary, are produced, the whole resting upon molecular physics and the action of the polar forces, which heat and electricity serve to intensify. And that this is also true, is fully proven by the circumstance that by simply reducing temperature, the move- ments are promptly arrested, while heat undergoes metamor- phosis into electrical force for energizing the polar forces, the same as in air and water, producing the vital phenomena. There ! that is your Vital Force. Commencing at the bottom, so to speak, of this problem, we have, then, the action in protoplasm to begin with. In undif- ferentiated protoplasm no form- elements present ; nevertheless, this animal (Moneron) is highly sensitive, responds quickly to irritants, performs voluntary movements, eats, respires, circu- lates its fluids, and reproduces itself, the form-elements (flrst nucleus) in the subsequent stages, or amoeboid development, the muscles and nerves in the compound organisms for ener- gizing the local actions and effecting coordination, that the whole may perform as but a single individual only, the vascu- lar system, respiratory apparatus and the other organs undergo- 440 NATTRE OF VITAL FORCE. ing commensurate changes with, the stage in development, there being a progressive onward movement in this direction ; while the whole relates to perfection of mechanical work for evolving the force which is expended in them in producing the varied movements, while this in turn relates to the struggle with gravitation, which is pivotal in development ; but coexistent with this, the law of pressure, which is being incessantly invoked by means of the rhythmical expansions and contrac- tions taking place in the organs and tissues for compelling circulation in the measure of the physiological requirements, which is also produced by means of heat and electricity, the same as for producing the voluntary movements and the actions in air and water. And if you would find Vital •Force, you would have to seek for it in heat-metamorphosis, with the sun as the common source of supply. The " Fire- Worshiper" had instinctively sought out this circumstance long since. And "he laughs best who laughs last." Notwithstanding, the evi- dence of an all-pervading Intelligence is incontrovertible. For impressing the circumstance of molecular action, we first bring before the reader the following forcible illustration (Fig. 187), by the famous biologist at Jena, representing eight presentations of the same animal (blood-cell of a snail), at as many moments during feeding. For example, beginning with ./, we have the spherical and more or less translucent condition the cell at first presents, then an extension of the branched processes (b) for pumping the fluids into the body, else flow- ing over them and so engulfing the food particles, then the conditions at c, d, e, f, g, h, all the while becoming more and more opaque from absorption of the food, till at last the condition is reached when no more food can be taken,- the ani- mal being full, as in the case of the sucking leech (Figs. 1 5-17), and for every stage in development, the corresponding increase in size being alike visible in all ; notably h is much larger than a, the full leech (Fig. 17) than the empty (Fig. 15). Now, then, in order to produce these varied changes of form in the cell, it is manifest that the cell-contents, the molecules equally with the masses, would have to change their relative positions, even to the nucleus (a, o), which occupies the root of a large branched process in g ; while in the subsequent condition (h), MOLECULAR MOVEMENTS IN CELLS. 447 in which the animal is fully contracted, restoring the original spheroidal condition (a), the nucleus occupies a nearly central position. In other words, we have definite actions and limita- tions in the protoplasmic substance, the movements directed to special objects, whether it relate to feeding or locomotion, in the entire absence of muscles or nerves, or any form-elements for producing them. Now, then, by looking from this to the actions taking place in the cells of compound organisms, in which muscles and nerves are developed, it will at once be seen that the same principle for producing motion is main- tained, and must be so in the very nature of things. In the Fig. 187. — Devouring Blood-Cells of a Naked Sea-Snail (Thetis) very much magnified. In connection with the blood-cells of this snail, I was the first to observe the impor- tant fact that " the blood-cells of invertebrate animals are uncovered lumps of proto- plasm, and, like the Amoebae, by means of their peculiar movements can absorb matter," can, therefore, "eat." When at Naples (on the 10th of May, 1859) I had injected the blood-vessels of one of these snails with pulverized indigo dissolved in water. I was much astonished to find after a few hours' that the blood-cells them- selves were more or less filled with fine particles of indigo. By repeated experi- mental injections, I was able to watch the absorption of the coloring matter into the blood-cells, which was accomplished exactly as by Amoebse. (See "Monograph of Radiolaria," 1862, pp. 104, 105.)— Haeckel. muscles, for example, in which changes of form in the muscle cells, produced by the molecular movements in the cell- walls and cell -contents, are referable the expansile and contractile actions in the muscles, in response to nervous force ; while the very fact that nervous force exerts this effect upon the mole- cules, shows at once it is also electrical, thereby producing the changes in polarity in the molecules, which is foundation and source of all the movements in animate as well as in in- animate nature. In fine, work is produced in muscles and animal tissues by means of heat metamorphosis and the action of electrical force, or the same as obtains in any mechanism in motion, only that in animal life it is automatic ; neverthe- less, every movement must have its equivalent in force, be paid 448 i NATURE OF VITAL FORCE. for at the time, there and then, else there could be no move- ment, consequently no life. Furthermore, we can readily understand why the pumping actions for increasing circulation should correspond with the activities, rising and falling with these, as everything is paid for by circulation, and this could not be made commensurate in any other way, pressure being invoked by the organs in the measure of the requirements for compelling prompt response, while for producing this it also calls for heat and electrical force, so that the principle is at once seen to be all-pervading. By reducing temperature simply, the action is promptly arrested in both animal and floral life. Thus, water (which is chief constituent of the tissues, and may be roughly estimated at three-fourths, the gray substance of the brain 80.5 decimals in the 100) freezes at a temperature of 30 de- grees Fahr., which would at once put an end to circulation, therefore of life ; but long before this reduction in tempera- ture is produced in the tissues, all visible phenomena have arrest, which establishes beyond question that heat is the agent for effecting the actions. Not that heat is actually life itself, but that life is product of heat metamorphosis, and the interaction of the polar forces in special forms of matter, as embraced in air and water, out of which the living organism is evolved. Finally, continuity (which undoubtedly exists) implies simi- larity in force, so that in every aspect of the case we see neces- sity for proceeding upon this basis, in order to make the matter intelligible. And since force connects through and through in order to produce the actions for sustaining life, nowhere more visible than in animal life, for producing the movements in respiration, circulation and the voluntary ac- tions, it follows that there should be some common principle, applicable alike to all, for effecting *the molecular actions in- volved in them, and which we find to be the polar forces, or the same as for producing the actions in air and water ; otherwise is inexplicable. In furtherance of this view, we have submitted the action in protoplasm, showing it is molec- ular ; but we would now contrast this with the action taking place in muscle cells during contraction, showing it is equally expansion and contraction. 449 applicable to this also, as the following forcible excerpt, by a distinguished German microscopist, clearly establishes :* "An important question still remains, which can be solved by the help of the polarizing microscope : Are the sarcous ele- ments to be regarded as single and individual elementary bodies, or as groups of solid bodies, capable of being variously disposed ? If the muscles contract, the fibres are seen to be- come thicker, and the transverse striae to approximate. Each sarcous element must consequently change its form and be- come shorter and thicker. If such a change of form result from any force acting in an elementary solid body, the opera- tion of the force must extend as far as the individual mole- cules, the optic constants must be changed, and it is nob con- ceivable that they should be so changed that the ordinary and the extraordinary ray, after they have traversed equal thick- nesses in the same direction, should present again the same difference in velocity that they offered under similar circum- stances before the change of form. But it is quite a different matter if the sarcous elements are groups of solid, doubly re- fracting bodies, of which each individual remains unchanged in form in the act of contraction. The form of the whole group — that is, of the sarcous element — is here changed by an alteration in the arrangement of the several corpuscles, just as in a company of soldiers, groups of various breadths and depths are produced by changes in the position of the»several individuals. In the latter case, the optic constants are not altered in the act of contraction, and the rays, on this account, if they have traversed equal thicknesses in the same direction, must constantly exhibit the same differences in velocity, whether the muscles be in the relaxed or in the contracted condition. Since we have a measure of the difference of veloc- ity in the colors which appear under the polarizing micro- scope, we are enabled to answer the question experimentally whether the optic constants of the contractile substance change during contraction to any considerable extent or not. All the investigations I have directed to this point have had a nega- tive result — i. e., I have never seen any alteration of color that * The Behavior of Muscular Fibres when Examined by Polarized Light. By E. Bnicke Strieker's Manual of Histology. 460 EXPANSION AND CONTKACTION. could not be entirely referred either to changes in the thick- ness of the layer traversed, or in the angle which the rays un- dergoing interference make with the optic axis. As, there- fore, I have in vain sought after a change of the optic constants, I must maintain that the sarcous elements are not elementary and simple solid bodies, but groups of smaller, doubly retractile bodies." This brings the molecular physics within the range of thought and distinct mental presentation. But then, the dis- tinguished author, it would seem to us, has omitted one-half of the mechanics, namely, expansion ; for expansion and con- traction are correlated forces. And keeping expansion for the time in view only, is it not as easy to perceive that it may be made the primary movement, the individual molecules going from the middle to the ends of the column, in order to effect it, then, by simply reversing the movement, produce contraction \ In point of fact, it necessitates as much discipline among the molecules in reversing the action as for producing the primary movement ; this, whether it relates to contraction or expansion. In short, that the molecules may go through either evolu- tion with equal ease and celerity, in obedience to special ner- vous stimulus which applies for effecting it. There would seem to be no reason why this may not be the case. Given that the molecules are held in their relative positions by the interaction of the polar forces (of which there is no room for doubt, since it applies to everything), it follows that dualism inheres in the mechanics, while movement is product of a change in polarity among the molecules. Furthermore, this principle in the mechanics would afford a ready explanation for a number of phenomena otherwise inexplicable, notably : a. How simultaneous action may be produced in opposite sets of muscles — e. g. , flexors and extensors with the obviation of friction and a waste of force, to the end that each should perform an active part in the work to be accomplished, and not hindering but aiding each other. But at present one set is made to pull the other into extension, which is unscientific, since it involves destruction or loss of equilibrium upon which the mechanics is based, not to mention rude friction and EXPANSION AND CONTRACTION. 451 waste of force thereby made inevitable. In place of this, how- ever, we have both sets of muscles acting simultaneonsly and in perfect concert with each other, while equilibrium is main- tained in this manner at any angle in flexion or extension, at the same time obviating strain and friction to the histological elements as well as the articular cartilages in the joints, other- wise inevitable. In regard to the latter, for example,, we may take the action in the hand. Spread it open widely, then tightly close it as a fist. How swiftly this is done! Well, is the enormous extension of the flexors in the first due to contraction in the opposing extensor muscles? and in the second is the prodigious extension of the extensors due to contraction in the flexors ? In this mechanics we would have the ends of the fingers in which the tendons are inserted -as the point oVappui from which force would have to be exerted in either case, and during closing of the hand the articular cartilages would have to endure rude friction from the rub- bing of the opposing tendons over them, increasing pari passu with the movement, so that when the hand is tightly closed the pressure upon the articular ends of the bones would necessarily be enormous, painful even to contemplate ; the same remark applying, of course, for extension, as the strain would have to fall upon the articular cartilages in either case. On the contrary, however, we are not conscious of any strain or fric- tion whatever, either in the ends of the digits or the articular ends of the bones, which shows conclusively that one set of muscles is not pulled into extension by the other, but that both act together and simultaneously, the one expanding as the other is contracting, and vice versa. b. But we have now to mention another important factor con- nected with musculation, which is also needing explanation, notably the extraordinary hardness and firmness produced in the muscles by nervous force during musculation, and increas- ing with the energy in expansion and contraction, since it ap- plies equally to both sets of muscles, to flexors as well as extensors, which are simultaneously affected. The following illustration (Fig. 188) will serve for impressing the matter. And with the weight in the. body thus resting upon the metatarsal bones, the foot fully extended, both sets of muscles to palpation 452 ELECTKICAL TENSION". seem as hard as iron, so great is the hardness. Furthermore, the hardness is in the ratio, of the weight sustained. For example, if the foot is extended when sitting or lying down, the muscles show only an amount of hardness ; but if a portion of the body-weight be then placed upon it, at once there is greater hardness, while this increases in the ratio of the weight, till finally the maximum is reached, when !Fig. 188. — Showing the great hardness which is produced in the muscles by nervous force when in energetic action, and which applies to both flexor and extensor muscles, proving the dualism in nervous force, or the power of producing siniul- taucous contraction and expansion in opposite sets of muscles, coordination being perfect. the whole weight in the body is thrown upon it ; pro- vided, of course, the party can endure no more than this ; otherwise it will continue to swell till the end of his physical powers is reached, for the hardness will correspond with the amount of work the muscles are performing. Taking work, then, as the condition for producing hardness, it follows that both sets of muscles, flexors with extensors per- form work during musculation. The great advantage of this is, that while it maintains equilibrium, thereby reducing fric- ELECTKICAL TENSION. 453 tion and conserving force and structure, it imparts great firm- ness to the articulations, the tendons acting as "splints" upon the joints, since the hardness extends to them as well. It is, therefore, obvious that one may not speak of "relaxation" at all in connection with musculation, being as wide apart as the ' ' poles' ' — antipodes. In short, "relaxation" is a state of rest, the very opposite to work ; at the same time, it also involves dualism, which is essential to equilibrium, for which purpose the limbs are placed at an angle between flexion and extension, therefore involving action in both sets of muscles in order to effect it ; hence, the. monistic theory of muscular force will not apply here either. Moreover, the crucial test of a theory is its power of absorbing all the phenomena. It comes to this, that the nervous apparatus itself is based upon the molecular or polar actions, its special office being to energize the polar forces for increasing the action in the organs com- mensurate with the exigencies in the functions, and for effect- ing coordination, to the end that a balance may be maintained in the organism, the whole performing as but a single indi- vidual. In Reference to the Cause of the Hardness in the Muscles, which is Produced by Nervous Force, and Increasing in the Measure of This. In casting about for a natural solution of the deeply inter- esting problem in musculation — notably, the great hardness and firmness produced in the muscles by nervous force — we are struck with the remarkable experience of Faraday with the electro-magnet, which, for several reasons, would seem to us to afford a natural and easy solution of the phenomenon ; more- over, it is in entire accordance with the fundamental principle in the mechanics — i. e., the interaction of the polar forces, intensified by electrical currents. For example, he discovered when the current was on in an electro-magnetic machine, that "a weight of several pounds of copper, when made to move through the magnetic field, though nothing is visible, appears to move through a viscous fluid ; while, when a flat piece of the metal is caused to pass to and fro like a saw between the poles, the sawing of the magnetic field resembles the cutting through 454 MOLECULAK ACTION AND ELECTEICTTY. of cheese or butter." And by connecting this deeply suggestive fact with that more recently ascertained in physiology (Helm- holtz, Holmgren, Burdon-Sanderson), namely, that electrical change precedes mechanical change in the sarcous elements, the hardness in the muscles which accompanies musculation increasing with the afflux of 'nervous force in the parts, would seem to us to be due to a similar cause, or the interaction of the polar forces intensified by electrical currents. In other words, that the hardness represents magnetic tension, pro- duced by electrical force, and that the nervous currents but a form of electricity, of which there can be but little doubt, con- tinuity in force for producing molecular action calling for this. Furthermore, it would afford an explanation of other phenomena, otherwise inexplicable ; notably : a. How the worms can erect their soft, tubular bodies almost perpendicularly with the utmost ease and celerity, when climbing and locomoting. b. It would afford an explanation for the extraordinary feats of strength displayed during periods of excitement sufficient to tear the muscles apart when out of the body, since the increase in magnetic tension in the sarcous elements should increase cohesive power correspondingly ; in this way subserving the highest uses in the organism by reducing strain, thereby con- serving structure and increasing function at one and the same time. For the muscle elements, being thus sustained by elec- trical force, and operated by electrical force, friction and strain during musculation are made impossible, a perpetual balance in force, which it necessarily involves, making it impossible. And, what is of equal importance, action is thereby unified, all the parts moving together in perfect order under electrical force, which pervades the mechanics through and through, producing the utmost concert in action. Having thus gone briefly over the mechanical principles in musculation, we are now prepared to take up special vital phenomena appertaining to musculation and circulation, hither- to inexplicable, the first in order being the demonstration of dualism in the muscles, which is readily done. An Easy Mode of Demonstrating Dualism in the Muscles. For this purpose we make selection from the worms, since there is no occasion for isolating the muscular fibres in them, DUALISM DEMONSTRATED. 455 the special arrangements which obtain making this unneces- sary, for the muscles being disposed in circular and longitudi- nal layers, the changes of form which the body undergoes is sufficient in itself to indicate the action in the muscles, while it gives us the actual facts in musculation, which the isolated fibre, removed from the cycle of organic forces and the volition of the animal, cannot possibly do. Furthermore, to reproduce the phenomena in musculation requires perfect knowledge of the special mechanics and the power on the part of the operator to isolate the positive and negative electricities ; at the same time, to so regulate the cur- rents as not to exceed the normal limits, which, it is needless to add, is difficult of attainment ; nevertheless, the power on the part of the animal to do this may not be doubted for a single moment, since the matter is fully proven by its ability to produce simultaneous expansion in opposite sets of muscles, and even in different portions of the individual muscle and muscular fibre, of which we shall give ample proof before we are done, commencing with the worms, notably the leech (Fig. 189), and ending with the higher animals. Here, of course, we must begin with the anatomy as means to ends, being the arrangements for producing worlc, while the special actions or movements observable, together with the laws of pressure and gravitation which apply, and the dual principle in nervous force for producing the molecular movements, will give us the method of doing this, which is what we wish to get at in the case. In short, whether there is actually dualism in muscles. Anatomy. — Fundamentally, the body of the worms is a hol- low cylinder, composed of circular and longitudinal muscular layers, the former external, the latter internal. In Annelides, the longitudinal fibres are increased, forming two dorsal and two ventral layers, leaving a lateral groove. In addition to this, a layer of transverse fibres, generally in the form of dis- tinct bundles, passes from the ventral median line to the lateral grooves, which enables the animal to flatten its body when swimming, passing through the water by graceful undulations of the body, which is flattened out, ribbon-like. The suckers are special differentiations of the dermo-muscular tube, which 466 DUALISM DKMONSTRATKD. agree with one another in all the essential points of their structure. The great relative thickness of the muscular cylinder is seen in the following illustration (Fig. 13, A, B, in). During feeding and locomotion the muscular layers are af- fected differently, the one directly the opposite of the other, B B J) Fig. 189. — Six Cuts of the Leech, showing as many changes of form, assumed within a few minutes, allowing for the time occupied in filling itself with blood, and neces- sarily involving simultaneous expansion and contraction in the circular and longi- tudinal muscles. A, before feeding ; B, when extending itself ; C, when feeding ; D, when gorged with blood ; JE7, when freeing his "feet" for locomotion, driving the blood to the central portions ; F, when locomoting. but acting harmoniously and in utmost concert, their joint action being essential for effecting the movements. Kow, then, and taking the state of rest as more nearly representing the condition of equilibration where motion is reduced to a minimum, we have presented to us the following appearance (Fig. 189, A), in which the animal is very small, nearly round DUALISM DEMONSTRATED. 457 or ovoidal in form. But when locomotion sets in, all this is changed (B), and from a short, globular body he assumes a long rod-like shape, extending himself to more than double the length he had when resting, while the anterior portions are drawn out to the dimensions of a bodkin or even less, so very attenuated they become. !Now, then, in order to effect this action, the circular muscles must contract and the longitudinal elongate simultaneously; otherwise it were utterly impossible to effect extension, since the one is greatly reduced in length, the other proportion- ately increased ; hence, the former must contract and the latter expand. No? Please explain, then, and make us understand how it is done. The short muscles contract and pull out the long muscles ! Nothing of the kind. Nay, impossible and preposterous. Look at the anatomy, and put a little thought into the matter. In the first place, the long muscles in the leech are more numerous, therefore more powerful than the short ; the weaker force, then, would have to overcome the stronger, which is not reasonable. 1. It would involve prodigious strain to the sarcous elements in the long muscles by being thus forcibly pulled to such extreme limits ; it could not be otherwise, in the very nature of things. Moreover, muscles will not admit of much forcible extension, resisting it promptly, and the greater the force applied the more they contract, tearing in twain when the limit is reached. 2. It would involve enormous waste of force, which is antagonistic to conservation of energy and of structure, which is funda- mental in the organism. Hence this rude mechanics, born of the monistic theory of muscular function, cannot possibly be correct. Fortunately, however, an easy method obtains for dis- proving it by actual demonstration, notably, hy feeding the ani- mal, when it becomes five or six times the size it had in the empty condition (A, D). Now, then, by looking from A to D, it is at once perceived that important changes in the muscles have taken place, notably that D is much larger than A, it is much longer than A — indeed, nearly twice its length, while in circum- ference it is a number of times larger. Hence both sets of muscles, the transverse as well as the longitudinal, are elon- 453 DUALISM DEMONSTRATED. gated. Which set, then, pulled out the other set? The "pulling-out business" will not answer at all ; one might as well try to lift himself by his boot-straps. Last, but not least, beneath muscular movement itself lies the law of fluid equilib- rium, which compels expansion in order to produce low pressure within the animal ; otherwise the fluids would not flow into the internal parts So then, we have both the law for compelling movement in the fluids and the fact in this enlargement itself, as indis- putable proofs of muscular expansion. And how can it matter whether we are able to reproduce expansion in muscles artificially or not % The bald fact remains that the animal, of its own volition, does it readily enough, and must do so in the very nature of things ; that ends the matter there : ttiis, however, that when the operator shall have produced expansion as readily as contraction in the muscles with the method of coordinating the movements, the mystery in vital force itself will have been solved, and the cause of these in- numerable "eddies " in the boundless ocean of Force laid bare to the investigator, for Life will then have been seen through and through. But since it involves metamorphosis in force, his investigations will be brought to a sudden stand-still on the threshold of that awesome fact — the heart of Nature's God, the unfathomable and unnamable All. The animal not only produces expansion as readily as con- traction, but the two actions are coordinated in producing cir- culation and the voluntary movements, since the method for increasing circulation by rhythmical changes in pressure in- volves alternate expansions and contractions in the muscles of the heart, vessels, and hollow viscera for compelling move- ment in the contents, the whole having adjustment with pressure and which applies to the mouth as well as any other portion. Thus, in the case of the sucking leech (0), the oral sucker is first expanded over the cutaneous surface {F), then gradually contracted for pulling up the artificial nipple, the pharynx at the same time expanding for drawing it into the chamber (c), where it is incised by the to-and-fro motion of the three serrated teeth in the pharynx by the alternate expansions and contractions in the muscles connecting with the cartil- DUALISM DEMONSTRATED. 459 ages, the enlargement forming the cnpping-apparatns (c), at the same time working energetically for aspirating and pump- ing the fluids into the canal ; thence propelled along the tube by alternating expansions and contractions contiguous to each other, as in deglutition, of which it is archetypal.* Finally, when gorged with blood, so that no more can be introduced (Z>), the suction-action must cease, for the limit in expansion is reached ; at the same time, however, this necessitates the power to maintain expansion for producing equilibrium in pressure, otherwise contraction, by increasing pressure, would compel reflux through the oral orifice, else the blood would escape by the anus, as when the animal is compressed between the fingers for the purpose of "stripping" him, which is by reflux action through the oral orifice, the terminal end of the gut being very small. Hence, all these movements involve dualism in the muscles, the notable circumstances being the energy in expansion, and the power of 'maintaining a balance, whether it relate to expansion or contraction, and which ap- plies for the voluntary movements, as well as for circulation. For forcible evidence of this circumstance, and the facility with which the action is reversed, compare D with E, in which the animal is getting ready for locomoting, by first compelling the blood from the terminal ends toward the central portions of the body, or behind the more central diaphragms, which are expanded for detaining it, so as to allow the feet to be used as in F. Here contraction is made as energetic as expansion had previously been, which is again as suddenly reversed lor expanding the feet, which are widely expanded to function as the basis of support in locomotion ; while to this again must be added the expansion which takes place in the posterior portions of the body, contiguous to the hind foot, for bringing the blood over the centre of gravity (F), thereby relieving the anterior portions correspondingly for assisting locomotion, enabling the animal to more readily elevate these portions in locomotion, the ends being raised and lowered alternately. But by reason of coagulation of the blood, which soon sets in, and the diversion of nervous force to the alimentary canal * In this case, gravitation aids muscular action, the fluids inconsequence passing more rapidly to the distal end of the stomach. 460 DU.aLISM demonstrated. and contiguous parts, this cannot readily be done ; hence the ineffectual efforts of the gorged leech to locomote, for the glutton is too heavily handicapped. In this position, how- ever (.F), it is easy to perceive that the dorsal muscles are greatly expanded, while the ventral are proportionately con- tracted, in order to produce the incurvated condition of the body. So, then, to begin with, we have first, the general tody-expansion (D), which must be maintained for retaining the fluids. In the second place, we have the central portions still more widely expanded for receiving the fluids in the ter- minal ends {B). Finally, we have the feet expanded and the body incurvated by expanding the dorsal and contracting the ventral muscles (F1). Hence, there can be no earthly doubt that expansion as well as contraction are alike subject to vol- untary control; otherwise it were utterly impossible to pro- duce the- above phenomena. The amount of nervous force absorbed in the digestive functions, and for producing circula- tion and maintaining equilibrium in pressure in the condition of repletion, should act as an enormous drain upon the cen- tral nervous system, and diminish in proportion the voluntary movements ; in consequence, he would become inanimate and sluggish to a degree — a condition quite common to gluttons ; and in the cold-blooded animal, in which respiration and cir- culation are at the minimum, of course, it would be more marked, inducing prolonged torpor. "We now pass to other phenomena in which expansile action in the muscles is made more energetic, notably the action in the tongue of the frog. The remarkable rapidity with which expansion and con- traction may be effected in the muscles has forceful illustra- tion in the tongue of the frog. Anatomy : The tongue of the frog is conrposed principally of two muscles, the genio-glossus connected with the mandible (Fig. 190, d, a), and the hyo- glossus (c) proceeding from the posterior cornua of the hyoid bone, together with the cartilaginous plate (b) which is pro- jected from the body of the hyoid bone as a supporting style, around the anterior end of which the hyo-glossus (c) curves to get upon the dorsal surface ; so that the tongue is bent upon itself, the terminal end presenting toward the fauces. DUALISM DEMONSTRATED. 461 At the point where the hyo-glossus curves over the end of the plate it forms a tendon, which facilitates the gliding action, over the cartilage when the organ is extended and retracted. When forcibly extended in the dead animal, the organ reaches to the edge of the mandible. Such, in brief, is the visible mechanics, which will answer the purpose of description.. Now, then, the animal has the power to project the tongue out of the mouth beyond the mandible with the rapidity of light- ning, extending it fully two-thirds the length of the body for hooking the prey and compelling it into the mouth, doing it so rapidly that the eye cannot follow it, the speed in extension and retraction being so great. And how is it possible to explain this phenomenon by the monistic theory of muscular action % Thus, contraction in the genio-glossus (d, a) could only pull the end of the organ to the edge of the mandible ; and with 5 c Fig. 190. — Diagrammatic Representation of the Tongue of a Prog, d, Tongue, reverted upon the cartilaginous plate (b) of the hyoid bone ; a, d, genio-glossus ; c, hyo-glossus muscle. both muscles acting simultaneously, it must pull the reverted end of the tongue forward upon a line corresponding with the insertion of the muscle in the mandible, or straighten it simply, and, of course, holding it in this position during the period of contraction, which is all this action in the muscle can possibly do, but which only puts the organ in a position to be suddenly projected from the mouth, . which requires elongation in both muscles in order to effect it ; otherwise is utterly impossible, as must appear obvious. The special elec- trical current for producing expansion is determined into the parts under the volition of the animal, similar to what occurs in the electrical organ of fishes, the principle being the same, pro- jecting and retracting the organ with the rapidity of lightning by reason of this action of the electrical current ; otherwise is inexplicable. Fortunately, however, we have a means of studying the action in the muscles ready to our hand, in which the movements are more slowly performed, but which. 462 DUALISM DEMONSTRATED. is equally conclusive of dualism in muscles and nervous force, notably in the tortoise, to which attention is now directed. Concerning the Movements in the Head, Neck and Tall of the Tortoise, with Reference to the Principle in Musculation. Dualism in muscles and nervous force has striking illustration in the muscular actions for producing the movements in the head, neck and tail of the tortoise ; but in order to place the matter fully before the student, it will be necessary to make brief reference to the special anatomy in the parts or the bones and muscles concerned in the movements, beginning with the cervical vertebrae. Cervical Vertebrae. — In chelonia the cervical vertebrae are elongated, eight in all, the last one (Fig. 191, 8), articulating with the first dorsal, is short and broad, with the anterior surface of the body divided into two transversely elongated convexities, the posterior forming a single convex surface, divided into two lateral facets, corresponding with opposite depressions and elevations in the first dorsal, forming the cervico- dorsal articulation ; the fourth (D) is elongated and convex at both ends, fitting into shallow depressions in the adjacent vertebrae so as to admit of the bending and folding up of the cervical chain within the excavation, the whole forming a figure very similar to the letter S reversed, the upper leg at the carapace, the lower (D) at the plastron. Cervical Muscles. — For producing the movements in the cervical vertebrae, beginning with the short and small seg- mental muscles in immediate contact with the bones, we have first, on the dorsal region, the longus colli (t), short fasciculi extending from the under part of the first and second costal jxlates and first dorsal vertebra, inclining forward and inward, to be inserted into the next adjacent vertebra, rising from one to be inserted in the other, the whole chain of short muscular links thus formed receiving this name; the " b i venter cerm- cis,J (e), from the neural plate and first dorsal to be inserted into the crest and fossae of the occipital bone, and from the fifth to the third cervical vertebrae, to be inserted into the crests of the occipital and temporal bones ; upon the sides seven short fasciculi, commencing with the eighth and ending with the second cervical vertebrae, known as "inter- DUALISM DEMONSTRATED. 463 transfer sarii colli,'''' with other fasciculi more obliquely dis- posed, corresponding with the fourth, third, second and first, known as the " intertr answer sarii obliqiiV ; upon the under surface "scalenus" proceeding from the lower three-fcurths of the scapula, to be inserted into each cervical vertebra from the eighth to the second (s), ' ' sternomastoicleus, ' ' proceeding from the sternum to be inserted into the mastoid process ; finally, the powerful uretra7iens capitis collique" (M) from the neural arches and spines of the eighth to fifth dorsal vertebrae, inclu- sive, to be inserted by four tendinous attachments, the long- est and strongest into the basi-occipital fossa, the other three into the fourth, fifth and sixth cervical vertebrse ; and over all of them the great cervical muscular sheath, " latissimus colli" (Fig. 17:.', 21, 25), inclosing the cervical muscles for retaining them in position, and assisting the action by com- pelling the articular surfaces to glide over each other ; this will serve the purpose of description. And it will not be neces- sary to name the muscles at the base of the skull connecting it with the proximal vertebra?, since they could do no work in effecting extension and retraction of the organs in the excava- tion The same applies for the muscles connected with the hyoidean apparatus. Now, then, the question, How are the head and neck of the tortoise retracted and folded up in the excavation (Fig. 191), thence extended again (Fig. 192), seeing that muscles act between the points of origin and insertion only? And since there is but one muscle — namely, the powerful "retra- Tiens capitis collique'''' (M), whose points of origin are pos- terior to the cervical flexure, it follows that this is the mus- cle for effecting retraction ; which is obvious enough. But the animal cannot live by retracting the head and neck ; hence this cannot be the chief function of this muscle, which is con- cerned in extending as well as retracting the organs. It would scarcely be contended that the small fasciculi connecting the chain of bones with each other are able to forcibly pull into extension the great muscular bundles in the retrahens, with all the advantage of leverage against them in addition. ±say? it cannot be entertained for a single moment, even. On the contrary, all the muscles are in harmonious concert in order to 4G4 Dl'ALISM DEMONSTRATED. effect these actions, the short fasciculi being the fine adjust- ments for compelling the articular surfaces to glide over each other, as force is being applied by the powerful muscles for effecting extension and retraction, all acting together and simultaneously, the muscular sheath at the same time facili- tating extension and retraction by contracting and expanding around the parts. But when the organs are being extended, the muscles connected with the sternum and scapulae {scaleni, sternomastodei) serve to guide the head and determine it in Fig. 191. — Skeleton of Tortoise (Emys Europcea) (Owen), showing the manner in which the neck and head are folded up in the excavation, forming a figure similar to the letter S reversed, the upper leg (a) at the carapace, the lower (D) at the plastron. the direction desired, the other muscles connecting with the vertebrae and head, at the same time assisting. And the movements not only involve consentaneous action in the muscles, but opposite action in opposing sets of muscles ; those upon the dorsal surface of the vertebrae undergoing elongation as those upon the ventral or lower aspect are un- dergoing contraction, and vice versa ; otherwise, extension and retraction of the parts could not be accomplished. Finally, since nervous force produces hardness in the muscles, we can readily understand how the great muscular bundles, by becom- ing more and more rigid as they elongate, should have the effect of pushing the head and neck out of the excavation for effect- ing extension, the principle being the same as in the worms, DUALISM DEMONS L RAT hD. 465 for extending and erecting the soft tubular body ; one set of muscles undergoing elongation, another and opposing set un- dergoing contraction, both sets increasing in hardness with S3 qq' < rs 4 c+ & 4 p 0 Mi 3 b X 0 <1 CD 4 eh CD c~ P B CD CD Oq eh tt 5 cr c CD w P CD Pi "i ^ P PiCR 0 1 0 55 05 p" 5' 3' 3' -~ 3" CO 5' B CD CD ft CD P P. 4 -1 0 B O pt o1 S3 CO ; CD * X 5" -. 3 72 w eh a<3 l-fc 0 4 p Pi JS 0} CD 2., Oq 0 cr a>" 1-+. 5 0 w c CD 0 CD B P 1 3 0 Ma B eh P =1 P< 3' CO B- 4 eh 0 C5> 4 5' CO CD B Pi J' g on" 3' £_ 3 p 4 3 ca J' ~. CO 1 CD eh eh B ■* O' 1 f tr 0 eh p CB CO O tf 3 CO a eh O B, O B 0 >. CI 0 e-i. 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In the tortoise we have a ready means of demonstrating this cir- 466 DUALISM DEMONSTRATED. cumstance, by turning the animal upon its back simply, then watching the result. Remember, it may be the first time it was ever upon its back, so that it would have to bring into action special muscles for the first time, making them perform the work it desires, which is to throw itself back again into the normal position, or upon the plastron. Now, then, the animal will not only extend the head and neck to the full limit, but curve them backward over the edge of the carapace, stiff and rod-like, the head against the ground, to function as a lever, which is used vigorously for the purpose ; at the same time, the tail also is extended and curved backward in a similar manner over the carapace ; while the limbs in contact with the groundwork vigorously, catching at any resisting surface. In this manner all the parts are employed, till at last the work is ac- Fig. 193. — The Deep Muscles in the Tail of the Tortoise. — Bojanus. complished, the ground favorable, performed quickly and deftly enough. Pausing to inspect the muscles of the tail, we find that here also the rjowerf ul muscles are below or upon the ven- tral surface (L94, c ; 193, 50, 5J, 52, 55), the short fasciculi upon the lateral aspect being removed in order to fully expose these muscles. With all the advantage of leverage against them, it is simply impossible for the short fasciculi to pull into such forcible extension the powerful muscles in the tail, as must appear obvious. And in the face of this overwhelming evidence to assert that the muscles do not possess dualism (not to mention the law in the organs of circulation compelling this circumstance, in order to produce the rhythmical changes in pressure), that they can- not expand as well as contract, exceeds the limits in reason and fair intelligence, blindfold though he be, seeing but dimly through the veil wrought by tradition and prejudice; but DUALISM DEMONSTRATED. 467 easily accounted for in the absence of the law underlying the organism and the fact that it cannot be produced artificially, tending to confirm and perpetuate the error. But we now see that the animal itself can make the muscles act in this manner readily enough, nay, must do so, in the very nature of things ; while the molecular actions it involves, admit of distinct mental presentation, and are natural enough, so that recourse to the supernatural is not at all necessary any more than for the phenomena in the physical sciences. But the evidence may be still more simplified, and with the object of bringing out in clear relief this fundamental princi- ple in animal mechanics, and laying bare the complicate arrangements that obtain in the structures and organs as ad- justments with the special functions, we again have recourse to the lower animals, this time the conchif era, which will subserve the purpose admirably. The Action in Conchif ers. — The species of Mollusk known as conchifers, or bivalves, also lamellibranchiates, from the lamellar branchiae or gills (Fig. 194, b, g), of which the oyster and scallop are the most common examples, have all the soft parts inclosed within two concave discs (or valves, as they are commonly called), which are opened and closed by means of a hinge-joint, and powerful muscles (c) connecting with the valves immediately in front of the joint, which is situated pos- teriorly ; some of them possess two such muscles widely re- moved from each other, which induced conchologists to form the conchifera into two sub-classes, or Monomyoria* and Dimyoria,f the latter the more numerous class, embracing the mussel tribe and many others. But for simplicity, we shall take examples from the first class only — namely, scallop and oyster. It is the common impression, born of the monistic idea of muscular function (forced to it from this circumstance), that conchifera open the valves by relaxing the muscles sim- ply, closing them again by contracting the muscles, the resist- ance in the spring, serving to open them when the muscles are relaxed, thereby making the so-called " adductor mus- cle" the antagonist of the wonderful elastic spring, of which * j.iovo'i, single ; ^vi, a muscle. jf Si?, twice ; mv?, a muscle — having two muscles. 46d DUALISM DEMONSTRATED. we have heard so much ; hence the name to this muscle. ]Sow, then, in order to probe this matter to the bottom, I made selection of the oyster, which has more elastic substance in the joint than any other, and applying a trephine over the inser- tion of the adductor muscle, succeeded in detaching it. "Well, the valves did not open, but remained cloned. Of course, they were no longer firmly held together, the muscle being de- tached, but the valves did not expand as they should have done according to the theory. The theory broke down then and there. The explanation is obvious. Thus, when the adductor ex- pands, it forces the valves open ; reversing the action contracts them ; while the special arrangement in the compressibly elas- tic ligament facilitates the action simply, making it more effective, using the force which is stored in it during contrac- tion for assisting expansion, thereby relieving the action in the adductor to this extent. And that this is the principle in the mechanics, is fully shown by the following circumstances, notably: 1. The valves are air-tight; the water they cor tain will not run out of them when inverted, so that the muscle would have to expand in order to open the valves ; which is announced by the noise they make when fed, the inrush of air producing the characteristic sound. 2. The action in the adductor in the common scallop during locomotion, for by energetically expanding and contracting the adductor, the animal propels itself through the water, effecting a retrogressive movement, the valves widely expanding and violently beating the water by contracting against it, forcing the animal back- ward through the water by this means, the expansile action removing the valves beyond the point where they could be influenced by the ligament. The wide divarication in the valves when found upon the beach, the soft parts all out of them, is due to the drying of the external ligaments, and the shortening this produces in them causes the valves to revert upon the beveled edges, so that when fully dried the valves are nearly at right angles. But nothing of the kind ever takes place when the ligaments are kept moist, as in the living animal. So, then, there can be no doubt whatever of the existence of a dual force in the adductor, or the power to ex- pand and contract under the volition of the animal. And DUALISM DEMONSTRATED. 469 turning from this, again, to the more complex movements in the higher stages in development — notably, the action in the jaws — and the same circumstance is readily proven on these muscles also, the stage in development, for obvious reasons, making no difference in this respect. The Principle in Musculation Applied to the Action in the Jaws. — Briefly, the muscles for opening and closing the mouth are the masseter (Fig. 195, 1) and temporalis (Figs. 196, 2, 195, 3), and internal pterygoid (Fig. 197), one for each side, Fig. 194. — Common Scallop (Pecten Jacobcea). — Jones, a, h, Lobes of the mantle ; b, g, branchial laniellse ; I, mouth ; k, lips ; c, adductor muscle ; i, " foot" ; d, e,f, visceral mass, principally filled with ova ; n, o, convolutions of intestine, seen through the transparent tegumentary membrane ; m, anal orifice. which expand and contract for the purpose, the principle being the same as in the so-called "adductor" in bivalves; and there are no muscles for opening the mouth by con- tracting for the purpose, barring the small floating muscles in the infra-maxillary region connected with the hyoid bone and tongue for operating these organs in connection with deglutition, sucking, speech, etc., in deglutition serving to approximate the base of the tongue against the epiglottis, so as to close the glottis and prevent intrusion in the air- passages, which is the principal function of the genio- hyo-glossus, genio-hyoid, mylohyoid, stylo-hyoid and digas- tric muscles ; the genio-hyo-glossus, in sucking by curving 470 DUALISM DEMONSTRATED. the tongue in the longitudinal axis so as to form a trough, the mylo-hyoid compressing it against the hard palate, forcing the aliment into the pharynx in deglutition, the other muscles acting in concert, the jaws closed for making the inferior maxilla the point of resistance. In other words, these muscles relate to the actions in the tongue and hyoid bone, and not to the jaws ; therefore, cannot be regarded as opponents to the massetal and temporal muscles, which assist their action by keeping the jaws approximated during deglutition and suck- ing, granting, for sake of the argument, they were strong enough to antagonize the great muscles in the jaws, which can by no means be done. But to remove every possible excuse for contrariety of opinion, I resolved to probe this matter to the bottom also ; and for the purpose made selection of a Spitz, and, placing it under chloroform, I swept the scalpel around the base of the lower jaw to the bone, and, twisting the bleed- ing vessels with torsion forceps, deflected the cutaneous flap, together with the platysma myoides, fully exposing the infra- maxillary regions, dividing first the anterior portion of the digastric near the insertion, then the genio-hyoid (dividing the muscles upon both sides), the mylo-hyoid at the attach- ment to the hyoid bone, not otherwise interfering with the floor of the mouth, finally snipping some of the fibres of the genio-hyo-glossus connecting with the hyoid bone, which completed the sections, not venturing to divide the muscle at the tubercles for fear of retraction of the tongue, pro- ducing suffocation ; nor was it necessary, since these fibres could exert no influence in divaricating the jaws. The flap was then carefully rejxlaced and secured by means of inter- rupted sutures. And the animal soon returning to conscious- ness, I punched him with a stick, which he bit viciously. That settled the matter there, showing conclusively that the masseters, pterygoids and temporals effect the movements in the jaws, or divaricate and close them by means of their action upon the inferior maxilla, which is done, of course, by means of expansion and contraction.* In this manner, then, the * The animal took no nourishment for over three clays, but the fourth morn- ing the milk had disappeared from the basin, he having drunk it some time during the night ; but he made a good recovery, the wound healing rapidly. DUALISM DEMOZSTSTKATED. 471 mechanics in the jaws are laid bare, and it is at once per- ceived that the principle is the same precisely as obtains in bivalves, through the action in the so-called "adductor muscle." Thus, the masseters, pterygoids and temporals open the mouth by expanding, reversing the action for closing it, the orbicularis oris expanding and contracting simulta- neously, all the parts acting in concert, while coordination is readily effected by means of the fifth and seventh pairs of nerves, which are correlated in the medulla oblongata, the fibres being also distinctly traced into it. The great relative size of the masseter (Fig. 195, 1), its ad- Fig. 195. — Section of the Upper and Lower Jaw, showing position and voiume ot the masseter muscle ; reduced.— Bougery, etc. vanced position in front of the hinge (2), closely embracing the angle of the jaw and much of the body of the bone, together with the number and disposition of the muscular bundles, stamp it at once as the chief force for opening and closing the jaws, the upper one being fixed. It is also manifest that by contracting the bundles connecting with the malar bone the angle and ramus of the jaw would have the effect of advancing the jaw, while the deep portions connected with the zygomatic arch and the body of the bone (not shown in the cut), would have the opposite effect, or retract the jaw ; thus opening and closing the jaw, and upon occasion moving it forward and backward for triturating the food. It is also obvious that the 472 DUALISM DEMONSTRATED. position of the muscles is most advantageous for economizing force, since it gives the greatest leverage, which is much in ex- cess of the temporal (3) inserted in the coronoid process, about an inch only in front of the hinge, or the width of the ramus itself (Fig. 196, 1, 3). The obvious purpose of this muscle is to assist the masseter in opening and closing the mouth and imparting greater force to the bite, being well developed in carnivora. Finally, to this force in the jaw we must add the action in the pterygoids (Fig. 197). It will be seen that the internal pterygoid is also a powerful muscle, resembling the masseter in form and the direction of its fibres ; only that they are from within outward, connecting the bone with the base of the skull, tending to pull the bone during contraction toward the median line, while the action, alternating with the opposite muscle, rocks it from side to side for effecting the grinding action in the jaw. The volume of the muscle, and its extensive points of origin from the pterygoid fossa, the pterygoid plate (external) and palate bone, and the great expanse of the attachments in the ramus, angle and body of the jaw, will give some idea of the force in this muscle. The pterygoids expanding simulta- neously would exert great force for divaricating the jaws ; reversing the action would close them with corresponding energy, contracting between the points of insertion compelling this* circumstance. In short, the pterygoids and masseters effect the grinding action in the jaws, moving the lower one upon the upper, which is stationary ; while the temporals in- crease the action for divaricating and closing the jaws. Such, in brief, is the tremendous force for closing the jaws by contraction, while there are no opposing muscles for open- ing it by contraction, the small floating muscles in the infra- maxillary region already referred to, with the hyoid bone fixed by means of the long, slender muscles (sterno-hyoid, sterno-thyroid, and omo-hyoid) connected with the sternum and scapulae, may have some influence in opening the mouth, but that they are not important muscles in this respect, is now fully proven to demonstration. The mouth is opened with great energy and celerity — opened as quickly as it is closed, and with considerable force. In proof of this latter circum- DUALISM DEMONSTRATED. 473 stance, let the student place his hand under the jaw with the object of arresting the action, and he will be at once convinced ; he will also produce pain at the head of the bone from strain to the ligaments, produced by the action of the muscles tend- Fig. 196. — Excision of the Zygomatic Arch, showing attachment of the temporal muscle (2) ; in the coronoid process (1) ; reduced.— Bougery, ebc. ing to force it downward and backward, the anterior portions being immovable. Furthermore, he will find by palpating the masseters that there is increasing hardness, or the same as with divarication in the jaw, and when fully opened the mus- cles seem as hard as iron, from afflux of nervous force in them ; and when making the experiment upon himself, a painful 474 DUALISM DEMONSTRATED. tension in the joint itself, as though enduring great strain, when the mouth is opened to its widest extent. Finally, this action in the muscles would explain disloca- tion in the jaw from muscular action, and the special arrange- ments that obtain in the parts for obviating it, otherwise inexplicable ; notably the existence and disposition of the external pterygoid muscles, one upon either side, for obviating displacement ; otherwise inevitable. For example, the muscle extends almost horizontally between the zygomatic fossa and Eig. 197. — The Zygomatic Arch and a Portion of the Ramus of the Jaw Removed, showing position of the pterygoid muscles. — Gray. the condyle of the jaw (Fig. Iy7) — a short, thick, powerful muscle, connecting the condyle with the superior maxillary, palate, and sphenoid bones, and spreading out widely over them, so that it is conical in shape, the small end being inserted into a depression in front of the neck of the condyle, and adjacent part of the inter -articular fibro-cartilage, the large end by two separate and broad insertions into the sphe- noid and superior maxillary bones, inclusive of the palate bone, so that an effective counter-force applies for retaining the head of the bone in position in the downward and back- DU.\LISM DEMONSTRATED. 475 ward movements, which is the direction of the force in the muscles for opening the month, and bnt for the action of the external pterygoids, strain and dislocation wonld be inevit- able in every widely opened month. The strong counter-force, supplied by means of these muscles, applied close to the articular ends, obviates this. Occasionally, however, the action in the divaricating muscles is excessive, forcing the body of the bone downward and backward so suddenly and forcibly as to dislocate the head, throwing it out of the articu- lating fossa, the action in the external pterygoid, which con- tracts simultaneously, pulling it forward over the crest of the fossa, where it is locked, the mouth open to the utmost limit, produced by yawning. This concentration of force at the head of the bone from widely diverging points in the base of the skull, effected by the two heads of the external pterygoid, corresponds with the plane of divarication through all its angles as the counter- force for maintaining the head of the bone in position ; other- wise the occasion for so large an amount of muscular force in this locality is inexplicable. At the same time, the insertion into the inter-articular fibro-cartilage would tend to give in- creased capacity to the articular cavity for effecting extensive motion in the head of the bone which is involved in the grind- ing action, showing also there must be action in the cartilage. In this manner, then, the special action in the parts is readily explained, while the adaptations of means to ends would seem to be absolutely perfect. Passing from this -as being sufficiently animadverted upon, we next take up the action in the circular and orbicular mus- cles, to note how readily the special phenomena appertaining to them are also readily accounted for and explained by the theory of a dual force in the muscles ; otherwise are inex- plicable. Concerning the Action in Orbicular Muscles. — In order to illustrate the action in orbicular muscles, our first example shall be taken from the iris, for the reason that rude force may not be spoken of here, where everything is exquisitely organized and action is perfect ; at the same time, there is a wide arc of movement in the muscles. But in order to make 476 Dl'ALISM DEMONSTRATED. the matter fully intelligible, it will first be necessary to make a brief survey of the special anatomy in the iris. Anatomy of the iris : Briefly, the iris is composed of two muscles, the circular and longitudinal, the muscular layers or lamellae, and a delicate stroma of fibrous tissue, in which the pigment cells, vessels and nerves are contained, the posterior surface covered by a thin layer of connective tissue and the uvea. *"The nerves of the iris are branches of the ciliary nerves of the choroid. After they arrive at the iris, they divide dichotomously in its external zone, form loops, and are finally resolved into a plexus consisting of nerve-trunks of medium size. In this plexus may be remarked an interchange of the fibres of the nerve-trunks, thus calling to mind the arrange- ment of the fibres in the chiasma nerv. opticorum. "From these points of intersection three kinds of nerve- fibrils take their origin : a, pale fibres, in all probability belong- ing to the sympathetica, which take their course toward the posterior surface of the iris (consequently toward the dilator), and upon it form an exceedingly fine plexus ; b, medullated fibres, which advance to the anterior surface, and these are resolved into a compact network of fine fibres — these are the sensitive fibres of the iris ; c, finally, a third plexus is dis- tributed within the sphincter ; its delicate fibres are for the most part motor." "The circular muscle (Fig. 19S, a) occupies the pupillary zone, extending outward for a distance of 0.09-1.3 mm. It is thinnest at the pupillary margin .(0.10 mm.), becomes thicker externally, and near the outer border attains a thick nessof 0.25 mm." According to ^Professor Iwanhoff, "the radiating fibres {bf are developed from the bundles of the sphincter as an uninterrupted continuation of the same. Its beginning is formed by a series of arched interlacing bundles, which lie partly within the sphincter (b, a), and partly on its posterior surface, between it and the pigment layer. These * A Manual of Histology, by Prof. S. Strieker, of Vienna, Austria, in co- operation with Th. Meynert, F. von Recklinghausen, MaxSchultze,W.Waldeyer and others. English translation. Art. The Organ of Vision. II. Tunica Vasculosa, by Prof. A. Iwanhoff, p. 856. DUALISM DEMONSTRATED. 477 isolated bundles, after they have passed the boundary of the sphincter, unite to form a continuous layer, which spreads over the entire posterior surface of the iris ; all its fibres lie regularly parallel to one another, and all are arranged in lines radiating from the pupillary to the ciliary margin. . ." The dilator pupillse (Fig. 198, b) is developed from the bundles of the sphincter as an uninterrupted continuation of the same. At the point of insertion of the radiating fibres into the ciliary muscles (Fig. 199, b, c) they bend suddenly upon themselves and return to the pupillary or circular muscle, some of the loops larger than others and lying in close con- tact with the ciliary muscles, others bending higher up the Fig. 198. — Segment of the Iris, viewed from the surface.— Jcropheef. a, Sphincter ; bt dilator. central portions in contact only (c, c), forming themselves into two layers (a, a'). Italics are added. From this it transpires that the sphincter is the chief muscle in the iris, while the radiating fibres serve for assisting the action simply. Indeed,, the eminent author in the same connection uses the following- forcible language : ' ' The literature on the dilator pupillse (radiating fibres) leads us unwillingly to the belief that until the time of Henle the existence of this muscle was pre- supposed on the ground of absolute physiological necessity, rather than actually demonstrated," r.ef erring to the preva- lent belief that muscles cannot expand, consequently that there must be opposing muscles for pulling the sphincters into extension, but which we positively know to be erroneous. Nay, more than this, one portion of the same muscles may expand or elongate as another is contracting /id shortening, both taking place simultaneously ; a fact which is fully 478 DUALISM DEMONSTRATED. demonstrated in the leech during imbibition (Fig. 16) ; indeed, is seen in every visible movement (Fig. 175). The former, however, will suffice. Thus at the oral orifice the sphincter and radiating fibres (which answer to the muscles in the iris) expand and contract together and simultaneously, the same applying for the bulb-like expansion (1), the longitudi- nal and circular muscles expanding and contracting simul- taneously, in the part adjacent the circular fibres are con- tracted only, in the next adjacent portion (2) both sets are again expanded, then another contraction of the circular less than the first ; finally both sets of fibres are simultaneously expanded, and continue to expand until the utmost limit is reached (Fig. 17) ; so that there can be no doubt whatever that both actions may go on simultaneously and in utmost concert. Fig. 199.— Arrangement of Muscular Bundles in the Iris.— 7b. a, a', The two muscular layers formed by the radiating fibres ; 6, b, the same suddenly bendirig upon them- selves before attachment to the ciliary muscle ; c, c, same fibres, showing degree of approximation to the ciliary muscle represented in subjacent border ground, or dark horizontal shading. Making the same deduction upon the muscles in the iris, the special phenomena in the expansion and contraction of the pupil are at once made intelligible, the two sets of fibres, circu- lar and longitudinal, expanding and contracting together and simultaneously under the action of the nervous forces in the parts, both cooperating to this end, the one assisting the other. Thus, for expanding the pupil the portions of the veil con- tiguous to the sphincter are gently pulled aside by the action in the radiating fibres, thereby facilitating the action in the DUALISM DEMONSTRATED. 479 sphincter ; while, for contracting the pupil, the circular fibres, by pulling upon the veil, would facilitate the action in the radiating fibres, so that the action is reciprocal. Nothing could be more perfect than the action in these muscles, but dualism is essential to it, and must be so in the very nature of things, as in no other way could a balance be maintained. And that there is such balance in nervous force to the muscles is susceptible of demonstration. For example, when the short root from the third pair (motor oculi) to the ciliary ganglion is divided, the pupil is at once closed ; but when the long root from the ophthalmic branch of the fifth pair is divided, the action is the very opposite ; the pupil as suddenly expands to the utmost limits, which shows undoubtedly opposite character in the two sets of nerve fibres, one producing contraction, the other expansion ; otherwise is inexplicable. In other words, dualism in nervous force. Then, again, either condition of the iris involves opposite action, so that the nerve-trunks must contain nerve-fibres to both circular and radiating muscles. This action in the circu- lar muscles brings to mind the action upon the blood vessels to the salivary glands (p. 284), produced by irritation of the special nerves, stimulation of the chorda tympani (Fig. 1 5, c) causing the vascular walls to expand, producing a rush of blood into them, while stimulation of the sympathetic fibres causing them to contract, thereby diminishing the blood in pro- portion. In the one case, nervous force regulates the amount of light in the eye ; in the other, the amount of blood in the glands ; the principle the same. And if it be, as alleged, " that the radiating fibres are an uninterrupted continuation of the circular," it would only show, as in the case of the leech and worms, that a given portion of a muscular fibre may be under- going expansion, while a contiguous portion is passing through the opposite movement. Moreover, there can be very little doubt but that the undulations passing along the muscles when stimulated, involve this circumstance, the two being inseparable in musculation. Finally, since the changes of form in the muscle-cells involve opposite movements in the molecular elements, it follows that the nervous apparatus for producing and energizing the actions should be in correspondence or be 4b0 DUALISM DEMONSTRATED. also dual, which would include the power of coordinating them in the functions, whether it relate to circulation, the vol- untary movements, or the action in the iris, etc., the principle being the same in all. And since it depends upon opposite polarities in the molecular elements, we can readily understand why electrical force should precede mechanical change in the muscles. All this, then, is at once made intelligible by dualism in muscles and nervous force ; otherwise is utterly inexplica- ble. We proceed to other phenomena Concerning the Action in the Oral Muscles — By easy men- tal process, we transfer the action from the orbicular and radiating muscles in the iris to the orbicular and radiating muscles in the mouth, in which the latter fibres are gathered into muscular bundles under special names, in place of being spread out in a uniform layer as in the iris. Indeed, accord- ing to some, the radiating muscles of the iris in the white rabbit (Fig. 2<)0, b, b) are gathered into bundles, but acting simultaneously for effecting the action in the pupil, whereas in the radiating muscles connecting with the orbicularis oris (Fig. 201, 7, 8, 9, 10, 11, 12, 13, 14) the action may be confined to several muscles at a time, which gives the power of express- ing the moral feelings and the great variety of movements characteristic of the parts ; at the same time, however, it in- volves the same principle in musculation and nervous force for producing them, related muscles expanding and contract- ing simultaneously in order to effect the actions ; otherwise impossible. In other words, the orbicular muscle is not for- cibly pulled into extension by the radiating muscles when the mouth is opened, but expands pari passu and simultane- ously with contraction in the straight muscles, and vice versa when the mouth is closed, all the parts acting in concert by means of the special nerves for producing and coordinating the actions. Furthermore, this is in correspondence with thev action in the powerful masseters, etc., for opening and closing the maxillee, already referred to, and which involves corresponding expansion and contraction in the orbicu- laris oris ; while the radiating muscles, by pulling upon the labise during divarication, facilitate the action in the orbicu- laris, as in the case of the iris, the principle being the same ; DUALISM DEMONSTRATED. 481 while by means of the fifth and seventh pairs of nerves run- ning into every portion, the actions are readily produced and coordinated. It is all plain enough. For effecting the variety of movements in the parts, it calls for the special anatomical dispositions that obtain, which are simply perfect. In some animals the oral slit extends very far back, so that when the jaws are widely divaricated it reaches almost "from ear to ear." It is the case in carnivora, and when the lion yawns it sends a quiver through the flesh. But critically examine that energetic action in the muscles of the jaws and mouth, and the marvelous concert that obtains in the multitudinous parts is suitable preparation for the less impressive but more exten- sive movements which are similarly produced and coordinated in the medulla oblongata, or the respiratory, circulatory and locomotory movements, together forming a connected whole, as has already been fully considered ; so that there can be no doubt whatever on the part of Nature to effect these ac- tions in the muscles of the mouth and jaws. For example, when the jaws are divaricated by the expansile action in the masseters, temporales and pterygoids, the orbicularis oris expands simultaneously and yari passu with this action in these muscles, at the same time thezygomatici (10, 1 1) and bucci- nator (IS) contract for pulling the angles of the mouth toward the masseters (15), the whole moving together and simulta- neously the same as in the muscles of the iris under the action of the nervous apparatus, which produces and coordinates the movements, the more complicate arrangements in the muscles making no difference in this respect ; while for closing the mouth the action is simply reversed, the utmost concert being maintained in the parts With progressive increase of expan- sile action in the muscles of the jaws, there is corresponding increase of contractile action in the retractors at the angles of the mouth, so that the overlying integument is thrown into the characteristic folds in front of the masseters. For producing the innumerable local actions connected with the lips, the numerous radiating bundles and fasciculi apply. But in these cases the action is limited to the special localities, in which a given portion of the orbicularis, in conjunction with the mus- cle proceeding from it, is affected. And since we know that 482 DUALISM DEMONSTRATED. nervous action may be limited to a part of a muscle only, the comprehensive arrangement which obtains here is something beautiful to look upon. The great mobility in the lips is un- doubtedly due to the number and variety of the local actions, which are swiftly changed and blended upon occasion by means of the nerves for operating and coordinating the structures. In the simple act of nursing, for example, it requires great mobility in the lips for effecting coaptation with the nipple and producing the movements concerned in sucking ; also, as organs of prehension in taking solid food. While to this, again, must be added the functions connected with oral sounds, Fig. 200.— Muscular Structure of the Iris of a White Rabbit.— Carpenter, a, Sphincter of the pupil ; b, 6, radiating fasciculi of dilator muscle ; c, c, connective tissue with its corpuscles. and as channels for announcing the emotions. Varied as are the uses, then, the numerous adjustments which obtain in the lips would not seem excessive ; nor the grouping of the radi- ating fibres into separate muscular bundles be deemed strange, the matter being altogether different from the simpler action in the iris, in which the radiating fibres form a uniform layer for producing the action in the screen concerned in opening and closing the pupil. At the same time, it is equally mani- fest that the same mechanical principle applies for producing the movements. We pass rapidly over this anatomy, the object being to show the principle in the mechanics simply, leaving the DUALISM DEMONSTRATED. 483 student to follow it at his leisure. By beginning with a prin- ciple upon which to base the mechanics, and proceeding from the simpler to the more complex forms, the comprehensive arrangements which obtain in the organs are seen to be but as many beautiful adaptations of means to ends, while order and method are made inevitable. In the orbicularis palpebrsB (4) we have another adaptation of the mechanics in the orbic- Pig. 201. — Muscles of the Head and Face. — Wilson and Buchanan. 1, Frontal portion of the occipito-frontalis ; 2, its occipital portion ; 3, its aponeurosis ; 4, orbicularis palpebrarum, which conceals the corrugator supercilii and tensor tarsi ; 5, pyra- midalis nasi ; 6, compressor naris ; 7, orbicularis oris ; 8, levator labii superioris alaeque nasi — the adjoining fasciculus between ciphers 8 and 9 is the labial portion of the muscle ; 9, levator labii superioris proprius — the lower part of the levator anguli oris is seen between the muscles 10 and 11 ; 10, zygomaticus minor ; 11, zygomaticus major ; 12, depressor labii inferioris ; 13, depressor anguli oris ; 14, levator labii inferioris ; 15, superficial portion of the masseter ; 16, part of its deep portion ; 17, attrahens aurem ; 18, buccinator ; 19, attollens aurem ; 20, temporal fascia covering the temporal muscle ; 21, retrahens aurem ; 22, anterior belly of the digastricus — the tendon is seen passing through its aponeurotic pulley ; 23, stylo- hyoid muscle pierced by the posterior belly of the digastricus ; 24, mylo-hyoideus ; 25, upper part of the stern c-mastoid ; 26, upper part of the trapezius. The muscle between 25 and 26 is the splenius. ular muscles. By reason of the form of the orbital excava- tion, the eye occupying the cavity, with a deep depression round it, together with the convexity in the upper lid, which is in close contact with the ball, a special arrangement in the muscles for opening and closing the eye is made inevitable, as the ordinary sphincter would not answer. Accordingly, we have comparatively but few circular fibres in the upper 484 dualism di-:mo.\sti:ated. lid, while the radiating or straight fibres form a broad triangu- lar muscle (levator palpebral), which joins the tarsal cartilage through its whole length, proceeding thence to the middle line of the upper portion of the orbit, to be attached to the optic foramen and sheath of the optic nerve at the very bottom of the excavation. Now, then, for producing the wide arc of movement in the upper lid is the explanation for the great length in this muscle, since it is the provision for effecting extensive contraction and expansion, for elevating and depress- ing the lid, while the breadth of the attachment in the tarsal cartilage makes the action simultaneous over the whole lid ; at the same time, the circular fibres serve for assisting the action, increasing the force for closing the lids, and by ex- panding facilitate retraction. But here, as elsewhere, the two sets of fibres are in utmost concert, expanding and con- tracting simultaneously. And so we might proceed from sphincter to sphincter through all the hollow viscera, in illustration of the antago- nism subsisting between the circular and the radiating or longi- tudinal muscles and the principle which obtains in the mechanics, but further extension is unnecessary, for it is all simple enough, and we cannot be misapprehended. More- over, the action in the sphincters has already been sufficiently considered in connection with the special functions in the viscera, in which it was shown that the sphincters expand as the sides and fundus of the organ contracts and vice versa, the principle being the same precisely as obtains in the iris and oral muscles. Concerning tlie Action in Erectile Tissue. — Finally, we come to the action in erectile tissue, in which we have a different order of phenomena, but which flow out of the properties in the muscles and in nervous force, before referred to ; notably, we have enormous expansion with hardness in the structures, which, after a short duration, again pass off, leaving them in a flaccid and shrunken condition, in striking contrast to what they had lately been when erect and fully expanded. Further- more, the action is rapidly produced. And being a product of nervous force, of course, it is susceptible of explanation ; but the ineffectual efforts to do so by the monistic theory of mus- DUALISM DEMONSTRATED. 485 cular and nervous action, shows necessity for introducing a new principle in animal mechanics, in order to make it in- telligible. Physiologists, in seeking an explanation, have recourse to the action in the penis, in which it was thought to be due to obstructed venous return from the organ ; but that this is not the true explanation is sufficiently obvious from the action in the tongue of the chameleon, where it cannot apply, and which we shall now briefly consider. Action in the Tongue of the Chameleon. — Anatomy: Briefly, the organ consists of two sheaths, an internal and an external sheath, in form of two cylinders, the one fitting in the other. The internal is formed of dense, fibrous and elastic tissue, the fibres decussating at right angles and in- closing a stile or supporting cartilage, projected from the body of the hyoid bone, which is closely invested by it, es- pecially in the lower portions of the sheath, where the attach- ment is very intimate ; but in the anterior portions the con- necting fibres are larger and longer, and admitting of con- siderable movement of the membrane upon the stile, permitting the organ in the relaxed condition to be folded up upon it much "like the seam of a dress upon a bodkin" (C, c), the end of the stile presenting in the lower lip of the bulb (A, a). And when thus folded within the mouth, the organ measures about one and one-half inches; but when extended, however, it is from six to seven inches in length, and projecting far beyond the end of the stile (B, b). But there is no canal, the elastic tissue fibres filling up and occupying the portion corresponding with the canal, the stile making its way through the interlacements when the organ is being folded up upon it. The large bulb forming the head of the organ is furnished with a short upper and a long lower lip (B, c, b), which are approximated in the relaxed condition, so as to form a transverse fissure, but in erection they are expanded, presenting a funnel-shaped open- ing (Fig. 203), with the lower lip extended and curving a little upward. The opening is also supplied with an orbicular mus- cle, which would explain the opening and closing of the lips for seizing the insect, while the glutinous secretions for lubri- cating the parts would cause it to adhere. Finally, a thin, muscular layer (hyo-glossus), composed of longitudinal fibres, 4fr6 DUALISM DEMONSTKATED. extends the whole length of the organ upon the lateral aspects (one on either side) ; while a large nerve courses on top of it to reach the head of the organ. The sheath corresponding with the mucous membrane is formed of white fibrous tissue, the fibres also decussating at va- rious angles, some running transversely, others longitudinally. (There is a difference of opinion in regard to the histological character of some of these fibres, which are believed, on the IN Fig. 202. — Tongue of Chameleon. — Cyclopaedia of Anatomy ; Art. Tongue. H. Hyde Salter. A, retracted ; B, elongated ; C, seen from beneath, in situ, by incision and separation of the integument ; a, anterior portion, dome shaped ; b, posterior por tion : c, upper lip of tongue ; b, lower lip of tongue ; e, genio-hyoid muscle ; /, cerato- maxillary muscle ; g, sterno-hyoid muscle ; h, cerato-sternal muscle ; i, omo-hyoid muscle ; k, apex of greater cornua of hyoid bone. part of some, to be unstriped muscle elements ; but since nervous force is not limited in its action to the muscles, it need not concern us.) Thus constituted, the organ is made to ride to and fro, forward and backward, by the action in the genio-hyoid (A, e) and omo-hyoid (g) muscles, while it is raised or lowered by means of guy-muscles (h,f) attached to the cornua (Jc) of the hyoid bone for aiming it at the object — much in the manner of a cannon upon the carriage. For effecting the movements in the opposing sets of muscles, of course, it requires dual action, the one expanding as the other DUALISM DEMONSTRATED. 487 is contracting, and vice versa ; in this manner materially assisting each other. 1 hus, as the genio-hyoid (A, e) contracts for pulling the hyoid carriage toward the oral orifice, the omo- hyoid (g) elongates for pushing it along, and vice versa for run- ning it back after erection. The same remarks apply for the guy-muscles, which are also made tense in this manner for regu- lating the point of elevation. Finally, when projected, it leaps off the stile in energetic action, going straight to the object as though shot ont of a pistol, and, striking the target, is as rapidly returned upon the stile in the folded condition, as previously. For effecting the former action, the circular fibres are suddenly contracted upon the network of elastic fibres oc- cupying the canal, while the longitudinal fibres elongate, and the hardening this produces pushes it off the stile in the erect position, and serving to hold it, rod-Wee, from the end of the supporting staff (20-J) ; otherwise it would fall and the end of the staff be caught in the fibres. Again, there is no central canal, for the circular fibres contract upon the network so as to convert the whole into a solid, stiff mass, and greatly re- duced in size in consequence (Fig. 20H), with the head con- tracted and elongated ; while for effecting retraction the action is simply reversed, the longitudinal fibres contracting and the circular expanding, and which would include, of course, the central network, for nervous force pervades the whole of it ; while the hardening this produces in the structures, as in ex- ample of the soft body of the worms, enables the actions to be produced ; otherwise is inexplicable. The tremulous action . in the organ previous to launching is produced by the guy- muscles (B, h, f)fov aiming the organ, while the bolt itself is suggestive of the discharge of electric currents through the organ by means of the large lateral nerves. But the partial and more deliberate protrusion which precedes the final dis- charge is due to the action of the muscles on the hyoid bone, or the genio-hyoid and omo-hyoid muscles ; but with the re- mainder of the phenomenon they can have but little to do, save for running the carriage back again at the end of the per- formance to the place it occupies in a state of rest. Finally, it should be borne in mind, in this connection, that when the organ is thus projected to the extremest limit in extension, it 488 DUALISM DEMONSTRATED. still retains perfect control of all its parts, else the movements in the end of the organ conld not be produced for seizing the insect, nor the sheaths be returned and folded up upon the stile ; so that in no sense can the action be regarded as a pas- sive one, or the product of a single force simply ; on the contrary, it is product of a dual force subject to the volition of the animal, and involving perfect coordination in all the parts for effecting it. Concerning the Action in the Penis. — This power in nervous force for producing expansion in the muscles, elastic and fibrous tissues would explain the phenomena in the penis, Pig. 203. — Tongue of Chameleon, when in action. — Jones. hitherto inexplicable, making this also plain and easily under- stood, the means to ends being very perfect. Anatomy : Briefly, the penile organ is composed of a mass of erectile tissue, in form of three cylindrical compartments, known as corpora cavernosa (which occupy the upper surface) and corpus spongiosum (containing the urethra), the lower surface, occupying the central groove formed by the corpora cavernosa, expanding over the ends to form the glans penis, which is firmly secured in position by means of connective- tissue fibres. The several bodies are contained in a separate sheath, com posed of elastic and fibrous tissue similar to the elastic coat in the arteries (Fig. 204, h), dense and thick, and closely bound together from the intermingling of the fibres along the sides, while within this outer tunic is a muscular cylinder, the two intimately interblending to form the com- mon wall (h). From the interior of this sheath (tunica albuginia) proceed numerous bands and cords (trabecules), which intersect, dividing and subdividing the interior into DUALISM DEMONSTRATED. 489 numerous separate compartments (d, d), lined by laminated epithelium — a continuation, in short, of the endothelial lining of the veins, with which they freely communicate ; and so free and intimate is this communication with the veins that they were at first taken to be mere venous dilatations, but are vascular spaces simply, formed by the trabeculse, into which the endo- thelial lining of the vessels is projected, or similar to what Fig. 204. — Transverse Section through the Spongy Portion of the Urethra (corpus spongiosum urethras). — Klein, a, ' Epithelium ; 6, tunica mucosa; c, muscular cords ; d, vascular spaces of the corpus cavernosum ; e, glands ; /, excretory duct of gland ; g, longitudinal muscles ; h, tunica albuginia. occurs in the uterine and placental sinuses (Fig. 137, c, c). Finally, we have large arterial capillaries emptying into these vascular spaces by funnel-shaped openings, for producing rapid afflux of blood in the parts, and embossed by dense nervous plexuses connecting with the nerves and structures in the penis, on the one hand, and with the hypogastric plexus on the other, by means of which the expansile action in the organ and the requisite blood-supply for filling and distending the vascu- lar spaces during the sexual orgasm are readily produced; 490 DUALISM DEMONSTRATED. the blood serving to give volume to the organ ; otherwise it would be needle-like ; hence these vascular arrangements This will serve the purpose of description. In the flaccid condition the organ is comparatively small, the dense fibrous and elastic sheath and muscular trabecule contracted, the organ less than one-third the size in the state of erection. Now, then, the question : How is this wonderful transforma- tion effected? Well, the only explanation that present physi- ology can offer (forced to it by the monistic theory of muscu- lar and nervous force) is the one of venous obstruction produced by contraction of the muscles at the root of the organ, com- pressing the veins, thereby causing the blood to dam back in the vascular spaces ; this, together with similar obstruction at the venous outlets of the vascular spaces produced by disten- sion (as suggested by others, not feeling sure that the former would be sufficient). But the following incontrovertible facts show conclusively that neither is correct, nor can it be in the very nature of things. Notably : a. The walls of the veins, in common with the universal rule, are very distensible, yielding readily under pres- sure ; hence, it were utterly impossible to force open the sinuses by this means or choking the veins, since it would involve the forcible distension and pulling of the thick trabecule and the dense fibrous sheaths inclosing the organ to fully double their length (not to mention the extraor- dinary hardness which accompanies it, and which, of course, would require corresponding force for producing it, involv- ing a degree of strain to the vessels, painful even to contem- plate), the veins as the point of resistance, the absurdity of the proposition is too obvious for controversy. The veins would burst under the force. Hence, it cannot be entertained for a single moment even. b. It would involve arrest of circulation in the parts, which cannot be thought of, for it would at once put the organ in peril, since this is simply strangulation — can be nothing else ; hence, in prolonged priapism, incidental to specific disease and abnor- mal irritati< >n, would inevitably produce necrosis or death of the organ, which never takes place from this cause. Moreover, it has been demonstrated (Eckhard) that in place of arrest, or DUALISM DEMONSTKATED. 491 even partial arrest, circulation is vastly increased in the organ during erection, the arteries being greatly expanded and the veins discharging an unusual amount of blood. c. Pressure in the sinuses could not exceed pressure in the arterial system, else reflux should inevitably occur, the blood escaping in this direction, and so relieving the struc- tures ; and since pressure in the sinuses could not exceed pressure in the arterial system, this would not be competent to force open the fibrous sheaths and trabeculse, and produce the characteristic hardness ; granting, for sake of the argu- ment, the veins could offer sufficient resistance, which can by no means be done. Hence the phenomena could not be pro- duced by damming the blood in the sinuses. d. It would not account for decline of erectile power with advancing years and the waning of general muscular force (they go together), for circulation is unimpaired in the parts, and secretion is abundant. Nevertheless, erectile power in the organ corresponds with the waxiug and waning of muscu- lar force, the minimum in extreme age. e. It would not explain the sudden flaccidity and collapse of the organ when in the state of erection from mental causes, disgust, fear, etc., since it would be utterly impossible for the blood to escape so rapidly in order to effect it. f. Last, but not least, it is utterly incompetent to explain the anatomy in the organ, notably the number of the muscles tra- versing the erectile tissue and forming the walls of the sinuses, together with a muscular cylinder far inclosing them beneath the containing sheath of fibrous and elastic tissue. Nor why the arterial capillaries should terminate in the sinuses by funnel-shaped openings. The explanation is easy, embracing all the phenomena, as a matter of course : notably, 1. The containing sheath and tra- becule expand under afflux of nervous force in the parts, the amount of this determining the degree in hardness. 2. Simultaneous with this expansile action in the erectile tissue, the arterial capillaries and trunks expand correspondingly for filing the sinuses or vascular interspaces, the suction force in the latter, together with the pressure in the arterial system, compelling them to be filled instantaneously, thereby pro- 492 DUALISM DEMONSTRATED. during enormous afflux of blood in the sinuses, the veins serving to carry off the excess, so as to produce a current through the organ and prevent reflux into the arterial sys- tem ; at the same time maintaining a flow of arterial blood through the structures for evolving the force in the muscles, which is essential to their action, in this manner obviating strain and preserving vitality, and which cannot be done in any other way ; while all the circumstances in the anatomy of the organ, inclusive of the funnel-shaped openings of the arterial capillaries, fall readily into line at the proper time and place, leaving no outstanding quantity refusing absorption, thereby proving the correctness of the premises. It is need- less to extend the matter. From this we proceed to other portions of the genital appa- ratus, making a brief survey of them also, for completing the description so far as it appertains to the special mechanics which we wish to elucidate. It will not detain us. Concerning the Action in the Vas Deferens and the Prin- ciple it Involves. — There is no hollow organ in the body more muscular, comparatively, than the vas deferens (Fig. 205), not excepting the heart itself, the cavitary space (Fig. 39) being relatively larger, comparing part with part. Thus, the vas deferens has three great muscular layers, the inner (c), middle (d) and outer layer (e) ; the inner and outer layers composed of longitudinal, the middle of circular fibres, the muscles being thus systematically arranged. Now, then, since muscles relate to work, why all this force for the vas. deferens? This also is easily answered ; notably, the spermatic fluid is highly albuminous and very tenacious ; moreover, has to ascend the tube perpendicularly (Fig. 206) ; hence, this degree of force for compelling circulation. But how compel % By contracting from below up ! Very well. But this involves several impor- tant circumstances for which we have been contending, nota- bly : 1. The fact of "automatism in the organs," which is absolutely essential to the performance of their functions ; also involving local mind centres for coordinating the movements, or the same as obtains for the separate independent organism, living and sustaining existence by itself. 2. It involves the principle for producing movements in the contents by means ACTION IX THE YAS DEFERENS. ^93 Kg. 205.— Transverse Section through the Commencing Portion of the Vas Deferens. — Klein, n, Epithelium ; b, tunica mucosa ; c, inner ; d, middle ; e, outer muscular- layer ; /, bundles of the cremaster internus ; g, vein containing muscles in its walls. Tunica Viyinalij Tunica JMluj in ia Klg. a06. — Vertical Section of the Testicle, to show the arrangement of the ducts. — Gray. 19 i DUALISM IN NERVOUS FORCE. of "rhythmical changes in pressure"; therefore, is based upon pressure, which is fundamental in the organism for compelling circulation in the measure of the physiological requirements, this whether it relate to the blood itself, the juices in the struc- tures, or the secretions in the organs. 3. It involves dualism in muscles and nervous force in order to effect the actions, or the power to produce expansion and low pressure in one portion, with simultaneous contraction and high pressure in a contiguous portion, whereby rapid movement in the contents, with obviation of friction and strain, are readily effected. A most notable circumstance in the vas deferens is the absence of valves for sustaining the fluids and obviating reflux ; this, notwithstanding the ascent is perpendicular, in order to reach the vesiculse semi- nales or seminal reservoirs at the base of the bladder (Fig. *207), where the fluid is stored for favorable opportunity. But the mucous membrane is in longitudinal folds, that increase in num- ber in the ampulla, the dilated lower extremity (Fig. 206), in which the muscles are also increased, and which, of course, have relation to and correspond with the amount of work that is in- volved for lifting the fluid up the tube. In other words, the ar- rangements which obtain are similar to what occurs in the bron- chial tubes, cesophagus, and stomach, for compelling movement in the contents, the folds in the mucous membrane, as in the other cases, being necessary adjustments with the action in the muscles, permitting them to expand and contract upon the contents in the measure of the requirements. A circumstance which strengthens this conclusion is the extension of the mus- cles into the mucous membrane, the fibres traversing it to the epithelium, so that simultaneous action in all the parts is thereby made inevitable. If will not be necessary to the argu- ment to enter into the minutia of the beautiful and won- derful anatomy in the testis, the number, variety, and ex- tent of the tubes (the totality said to approximate a mile in length); suffice it to say, that we have this delicate struct- ure, the problem being to remove the secretions as fast as they are formed. And it is not to be supposed, for a single moment even, that the powerful ampulla, into which they are previously discharged (passing through a narrow muscular DT.ALISM IN NERVOUS FORCE. 495 portion to reach it), is forcibly distended by the tnbules by compelling the fluid into it ; but, on the contrary, that this expands from the sensory impressions in the mucous surface produced by the fluid, the same as the gall-bladder, urinary bladder, or the pelvis of the kidney and ureter, to which the structures are more closely approximated ; till finally, the limit being reached, the receptacle contracts for compelling it out, driving it up the tube, contraction beginning from below and continuing on up the canal in a series of rhythmical expan- sions and contractions, similar to what occurs in the oesopha- gus and the body of the worms, with which the structures are homologous, the same law applying alike to all, and necessarily involving similar arrangements in the structures for producing the work. In the present case we have the great abundance of longitudinal muscles (Fig. 205, c, e) for effecting shorten- ing in the tube, thereby diminishing the distance and reducing work in proportion, while the circular muscles (d) effect the rhythmical changes in pressure for compelling movement, the fluids here, as elsewhere, flowing from high to low pressure in conformity with organic law. In other words, the special adaptations relate to work, while force is applied in the measure of the requirements (and widely removed in function as is the local vein (g) coursing through the structures, can it be doubted, for a single moment, that the muscles in its walls also relate to work, contracting from below up for forcing the blood to the heart and lungs, the same law applying to both ?). The nerves are situated in the tunica adventitia, and form a pretty dense plexus — the plexus spermaticus — in a portion distant from the cremaster internus, and are derived from the spermatic and sympathetic. From the plexus spermaticus issue several smaller nerve-trunks, which penetrate the mus- cular and mucous layers of the vas deferens, where they are observed to have medullated fibres (Klein).* "In the upper portions of the vas deferens small ganglion cells are scattered in the nerve-trunks of this plexus, and also in those trunks lying more externally and running separately. In the neigh- borhood of the ampullae, however, there are some quite feebly- * Strieker's Manual of Histology. Art., Male and Female External Genital Organs ; together with their Glandular Appendages, p. 584. By E. Klein. 496 DUALISM IN NERVOUS FORCE. developed ganglion cells." It will thus be seen the nervous supply to the organ for producing and coordinating the move- ments spoken of is abundant. Jlt'l/Jlt Ej'aetiUUry duct Fig. 207.— Base of the Bladder with the Vasa Deferentia and Vesicula? Seminales.- Gray. §bv^Olv Fig. 208.— Transverse Section through the Wall of a Seminal Vesicle.— Klein, a, Epithelium ; 6, mucous layer ; c, internal ; d, middle, and e, outer muscular coat ; /, adventitial tunic ; g, ganglia. From a child. After the fluid has reached the seminal reservoir, it is still within the embrace of muscular and nervous force, the ar- rangements which obtain in the parts being fundamentally the same as in the vas deferens, only that the cavitary space is DUALISM IN NERVOUS FORCE. 497 larger and the rugse in the mucous lining more extensive (Fig. 208, a), the muscles (c, d, e) not quite so numerous, compara- tively. Thence it is compelled into the urethra within the grasp of the ejaculatory muscles during the sexual orgasm, whence it is driven out of the body with great energy under the action of the special nerves. The large nervous ganglia (g) in the adventitia (/) very probably serve for coordinating the vas deferens with the action in the walls of the reservoir, as also for compelling emission, in this manner holding similar relations to the. ganglia of the renal plexus for producing and coordinating the actions in the kidney, pelvis and ureter for compelling movement in the contents, the matter being one of variety simply. For present purposes it is needless to extend the matter. Striation and Fibrillation.— There can be very little doubt that striation and fibrillation relate to electrical tension and increase of power in the muscles for producing energetic ac- tion. In the slow-moving snail, for example, there are no striated muscle fibres ; but in the earthworm and leech, which possess considerable energy, the striated are freely inter- spersed with the non-striated muscle fibres. In the tongue of the frog, in which the action is very energetic, the muscles are strongly striated (Fig. 209). In the slow-moving tortoise, it might be urged, the muscles are also striated ! Yery true ; but it is no exception, and ad- mits of easy explanation. Thus for lifting and transporting the heavy house-like body it calls for the expenditure of considerable force, hence the striated muscles for operating the bony levers, cervical and caudal vertebrae ; while the slow movements in the body result from the defective and embarrassed respiration, pre- venting that degree of oxygenation of the blood which is essential for rapid locomotion, the whole forming a con- nected movement in the very nature of things, for evolving the force which is expended in the activities, as has already been fully set forth; hence this circumstance. But in the individual members action may be made very energetic, nota- bly, the retraction of the head and limbs when the parts are irritated, the animal doing this quickly enough. The fishes 498 STRIATION AND NERVOUS FORCE. move rapidly and possess great muscular power ; the muscles are striated. In short, striation in muscles corresponds with the degrees of energy and force. This circumstance has striking illustration in the hollow viscera of the warm-blooded animals, notably the heart, terminal portions of the rectum, the ejaculatory mus- cles in the urethra, and the paunch of the ruminant, in which the muscles are striated, whereas in all the other viscera the muscles are of the non-striated variety, for the reason that rapid action is not called for. Finally, in embryognesis, Fig. 209.— Isolated Muscular Fibre with Transverse Striae from an Oblique Section of the Tougue of a Frog Colored with Chloride of Gold. The muscle cells are distinctly shown, and three are visible, each containing several nuclei. P. 61 (Oc, 3 ; obj. 8). Klein. in which development repeats itself, we have the transitional stages in muscle evolution also manifesting itself, the fusiform cells of non-striated muscle fibres inosculating and under- going progressive striation (Fig. 210). Then, again, we have experimental evidence showing electrical phenomena in the muscles during musculation, notably: 1. Every cross- section of a striated muscle represents a negative pole of an electric current, and every longitudinal section a positive pole ; and it is immaterial whether the section be made with a knife or corrosive substance ; while muscles which are rigid, or which STRIATIC^ AND NERVOUS FORCE. 499 have been killed without "rigor" being induced, exhibit no current. Du Bois-Reymond (Hermann). 2. That during the passing of a wave of contraction along the bundle of fibres, produced by stimulating the end, that the different spots in Fig. 210. — Muscular Fibres from a Foetal Sheep in Process of Striation. — Frey. a, &, Very long fusiform cells, two or three nuclei and commencing striations ; c, d, por- tion of a somewhat more mature fibre, with numerous nuclei and considerable diameter ; e, /, g, fibres still further developed, with nuclei in the axis ; h, nuclei beneath the envelope ; i, a fibre breaking up into thick disks. succession on the longitudinal surface become negative in reference to other spots, there being a negative wave, as it were, which travels along at the same rate as the wave of con- 500 STRIATION AX1) NEK VOL'S FORCE. traction, viz., aboat three metres per second (Bernstein'*)f "At each point the negative state, which first increases and then decreases, lasts about vhs of a second ; it is entirely gone by the end of the 'latent period,' which lasts T*ff of a second. Every point in a fibre must therefore first of all undergo electrical changes before contracting (Helmholtz, Holmgren) ; or, in other words, the wave of muscular contraction is imme- diately preceded by a negative wave. . . . The state- ment that this negative wave diminishes in intensity as it travels on (Bernstein) appears only to apply to the case of muscle which is dying (Du Bois-Reymond)." Italics are added. It will thus be seen that dualism in muscles and nervous force is further corroborated by the electrical phe- nomena occurring in the muscles during musculation, the difference in the currents answers to the opposite molecular changes in the sarcous elements corresponding with expan- sion and contraction ; otherwise are inexplicable. But the most striking circumstance, the fact that the negative wzve, which answers to expansion, precedes the positive, which answers to contraction, in the muscles ; the importance of which it would be difficult to overestimate, since it underlies the mechanics for effecting circulation, so that diastole in the heart, vessels, and hollow viscera is not only in conformity with the law underlying the movement in the fluids, but is further made inevitable from the very nature of the mechanics in musculation ; and the two being correlated forces in nature, are readily coordinated in the animal functions by means of the nervous apparatus, which, as it were, separates and limits the two forms of electrical force, pouring one or the other into parts, so as to produce rapid expansion or con- traction in the organs, as the case may be, in the exigencies in the functions ; which would explain the special phenomena, while nothing else would. In short, the nervous system con- trols the electrical currents in the muscles ; at the same time, they may be induced artificially, to wit : * Bernstein, Untersuchungeri iiber d. Erregungsvorgang im Nerven und Muskelsysteme. Heidelberg. 1871. f Human Physiology, pp. 291-292. By L. Hermann, Professor of Physiology in the University of Zurich. STEIATION" AND JSTERVOl'S FORCE. 501 * '•'In a perfectly uninjured, unskinned animal the mus- cles, which are in a, state of rest, are entirely free from elec- trical currents (Hermannf) ; the currents originate during the preparation of the muscle, in consequence of injurious influ- ences acting upon their surfaces. In frogs, for instance, among other such influences, is to be mentioned the action of traces of the caustic secretion of the skin. The more these injurious influences are avoided, the greater the freedom of the muscle from electrical currents. In muscles which are at rest there are, therefore, no currents except those which are brought about by the negative electric tension of the artificial cross- section in reference to the longitudinal section" (Hermann). Then, again : % In the electrical stimulation of muscles, the same laws hold as in that of nerves. Here, also, it is only variations in currents that produce stimulation, which, as before, proceeds, on closing, from the cathode, and, on open- ing, from the anode (von Bezold). As changes take place more slowly in muscle than in nerve (as evidenced, for example, by the different degrees of rapidity with which they transmit impressions), length of duration of the stimulating current is more necessary in the former than in the latter for the production of stimulation. Hence, all induction-currents, and the more transitory constant currents, are unable to stimulate to contraction muscle deprived of its nervous connections by curare, while they are able to cause contractions in a muscle by acting upon its motor nerves (Brucke). This fact was early known to be the case with muscles, the nervous organs of which were rendered inca- pable of performing their functions by exhaustion, local death, pathological paralysis, etc. (von Bezold, Fick, Neu- mann) " The above brief excerpts will be sufficient to show the nature of the mechanics in musculation and nervous force. Last, but not least, we have to mention the sugges- tive fact in the "striae" themselves (Figs. 211, 212), which differ essentially from each other, and placed one above the * Hermann, Weitere Untersuchungen uber den Stofftvechsel in Muskel. Ber- lin, Verlag v. A. Hirschwald. 1867. f Hermann's Physiology, pp. 285-286. X Ibid., pp. 339-340. 502 STHIATIOX AND NKKVOUS FORCE. other alternately, sustain striking resemblance to what obtains in a Voltaic pile (Fig. 212, a, b), the sarcolemma inclosing them ; also, that during musculation the muscle juices give an acid reaction, which corresponds with the conditions in an electric pile. Furthermore, the force which is manifested in Fig. 211.— Fragments of Striped Elementary Fibres, showing a cleavage in opposite directions ; magnified 300 diameters. — Todd and Bowman. A, longitudinal cleav- age—the longitudinal and transverse lines are both seen ; c, fibrillar separated from one another by violence at the broken end of the fibre, and marked by transverse lines equal in width to those on the fibre ; c', e", represent two appearances com- monly presented by the separated single fibrillae (more highly magnified) ; at e' the borders and transverse lines are all perfectly rectilinear, and the included spaces perfectly rectangular ; at e", the borders are scalloped, the spaces bead-like — when most distinct and definite, the fibrilla presents the former of these appearances. B, transverse cleavage — the longitudinal lines are scarcely visible ; a, incomplete frac- ture following the opposite surfaces of a disk, which stretches across the interval and retains the two surfaces in connection — the edge and surface of this disk are seen to be minutely granular, the granules corresponding in size to the thickness of the diskr and to the distance between the faint longitudinal lines ; 6, another disk nearly detached ; b\ detached disk, more highly magnified, showing the sarcous elements. Fig. 2 IS. —Piece of Dead Muscular Filament from the Fly.— Engelmann. a, a, Trans- verse disks ; b, accessory disks. the muscles during energetic action, sufficient to rend them asunder, is not explicable by any other theory than the one of polar action, which should increase cohesive power with afflux of electrical force ; while the progressive increase in hardness is also not explicable by any other theory. From what has preceded, it follows : 1. That striation and fibrillation relate to increase of energy in the muscles. 2. That two forms of GENESIS OF NEKVOUS FOKCE. 503 nervous force exist, which, answer to the two poles in the electric current, or positive and negative ; while the principle for producing motion in muscles is by changing polarity in the molecular elements, which is the function of the nervous appa- ratus. The regular intervals and correspondence between the striations, the transverse markings in all the fibres occur- ring at the same intervals (Fig. 211), should facilitate the passage of the nervous currents and effect concert of action. The mode of nerve-terminations also throws some light upon it. Thus, the wall or sheath of the nerve-tubes (Fig. 213, B, 1, 1) blends with the sarcolemma (3, 3), with which it is continuous, the terminal nerve-plates (5, 5) being within the sheath of the muscle-plates, in immediate contact with them, the medullary substance of the nerve-tubes (4) ceasing abruptly at the site of the nerve-plate, whence electrical force is diffused through the muscle-plates by means of the granular substance which forms the principal part of the nerve-plate, and which may be regarded as distributors of electrical force, which is not by sharp points, but blunt or spherical bodies, so as to more uniformly diffuse it through the fibre, taking from the medullary substance and transmitting it through the muscle-plates. But here again comes up an important question ; notably : ' ' What becomes of the force which is generated in the muscles, seeing that this is the princi- pal seat of oxidation and source of body-temperature ? And while heat rapidly diffuses itself through the tissues, and is removed by the passing blood, we know that considerable pro- portion must undergo metamorphosis into electrical force, or similar to what obtains in the external mechanics. The impor- tance of this question will at once be seen when contrasted with the amount of work performed by the muscles, which must have its equivalent in electrical force derived from some source, and paid for there and then. Take a medium-sized man, or one of one hundred and fifty pounds, for example, during locomotion. He rises to the erect position and steps out — first one, then the other leg, following each other in rapid succession in locomotion ; the force which does this emanates in the brain, but having started the me- 504 GENESIS OF NERVOUS FOKCE. clianics fairly and well, the tiling runs itself from the spinal cord by what is known as "reflex action," propagated through the spinal medulla, the brain itself having little to do with it. Nor can it be imagined for a single moment even that the force for producing all this work is generated in the cord itself, the special nervous centres involved being far too inadequate for this, admitting even that the principle was right, which, for obvious reasous, can by no means be done. On the con- Fig. 213.— Mode of Nerve Terminations in Striated Muscles.— Rouget. A, primitive fasciculus of the thyro-hyoid muscle of the human subject, and its nerve tube ; 1, 1, primitive muscular fasciculus ; 2, nerve-tube ; 3, medullary substance of the tube, which is seen extending to the terminal plate, where it disappears ; 4, terminal plate situated beneath the sarcolemma, that is to say, between it and the elementary fibrillar ; 5, 5, sarcolemma. B, primitive fasciculus of the intercostal muscle of the lizard, in which a nerve-tube terminates ; 1, 1, sheath of the nerve-tube ; 2, nucleus of the sheath ; 3, 3, sarcolemma becoming continuous with the sheath ; 4, medullary substance of the nerve-tube ceasing abruptly at the site of the terminal plate ; 5, 5, terminal plate ; 6, 6, nuclei of the plate ; 7, 7, granular substance which forms the principal element of the terminal plate, and which is continuous with the axis- cylinder ; 8, 8, undulations of the sarcolemma reproducing those of the fibrillse ; 9, 9, nuclei of the sarcolemma. trary, the work involved in transporting the body is paid for by means of oxidation of fresh materials brought into the muscles by means of respiration and circulation, which are in correspondence with the activities, so that the force is neces- sarily generated in the muscles themselves ; but since the nervous apparatus produces and regulates the muscular move- ments, it follows that the force so generated would have to pass into the nerves to the spinal cord, thence out again into the muscles, the nerves serving to conduct it to and fro be- tween the muscles and the ganglia, under guidance and direc- GENESIS OF NEKVO'S FORCE. 505 tion of the ganglia, which determine the movements. In short, it wonld seem to ns that the electric force generated in the tis- sues passes np one set of nerves, notably the so-called "sen- sory nerves," to the posterior columns of the cord (Fig. 214, 13), thence through the gray matter of the cornua, and out again through the anterior roots or "motor nerves" (11, 11, 11) from the anterior columns to the muscles, the nervous ganglia in the cord serving to separate and limit the currents, so as to A. Fig. 214. — Transverse Section of the Spinal Cord at the Origin of the Fifth Pair of Cervical Nerves. — Stilling. In this figure, the white substance of the cord is repre- sented in black, to show more clearly the limits of the gray matter ; 1, 1, antero- lateral columns ; 2, 2, posterior white columns ; 3, anterior median fissure ; 4, pos- terior median fissure ; 5, white commissure ; 6, gray commissure ; 7, central canal ; 8, 9, anterior cornua of gray matter ; 10, 10, group of large multipolar cells ; 11, 11, 11, anterior roots of the spinal nerves ; 12, posterior cornua of gray matter ; 13, posterior roots of the spinal nerves. specialize, at the same time regulating, the energy of the movements in the muscles, and so as to produce expansion or contraction, as the case may be, in the exigencies in the functions ; otherwise impossible. We know, too, that the nervous apparatus regulates respiration and circulation for evolving the force ; that it regulates temperature by means of the vaso-motor centre, compelling the blood to the skin sur- face for cooling it, which would involve control of the whole mechanics, and by implication the force generated in the mus- cles ; otherwise it would be utterly impossible to produce, regulate and coordinate the movements in the muscles, as 506 GENESIS OF NEUVOUS FOKCE must appear obvious. Hence, we must conclude that the force generated in the muscles passes up to the cord through one set of nerves and down again through the other set. This principle in the mechanics has further corroboration in what occurs in the case of the sympathetic ganglia (Fig. 215), in which there is similar arrangement, the nerves passing into the nerve knot through one of the converging trunks, to pass out again at another portion of the knot. Nay, further, the primitive fibrils pass into the separate cells and out again Fig. 215.— Sketch of a Mammalian Sympathetic Ganglion.— Frey. a, b, c, Nervous trunks ; d, multipolar cells ; d, some of the latter with a dividing nerve-fibre ; e, unipolar, and /, apolar cells. from the opposite side, forming multipolar cells (d), some of the latter {d*) with a dividing nerve fibre. Why some cells (e) have only one fibre is explicable only by the hypoth- esis of a special form of nervous force ; while the apolar cells (/) would refer to separating and disuniting the fluids, which are transferred to the muscles through the adjacent cells and nerves. This would explain the presence of the gan- glion on the posterior root of the spinal nerves (Fig. 113, A\ with the fibres running into and out of the cells, thereby re- lieving the ganglia in the spinal cord to that extent, and all sensory nerves are thus intersected by a ganglion knot. The more numerous the fibres, the larger the ganglion ; notably the fifth and the eighth pairs, the latter possessing actually GENESIS OF NERVOUS FOKCE. 507 two such ganglia. And being the universal rule, it cannot be doubted for a single moment that they have important func- tions : in short, tha,fc they effect some change upon the nerv- ous fluid ; otherwise are meaningless. This circumstance has forcible illustration in disease of the posterior columns of the cord, notably "progressive locomotor ataxia," in which this transference of electric fluid through the nervous arc in the cord is arrested, and every movement is made directly from the brain, and necessitating the concentrated attention and volition of the patient in order to effect locomotion, which is extremely difficult, showing conclusively that the main source of force for effecting it is in the muscles themselves and the changes effected upon the fluid in the cord itself. In short, it underlies the principle in "reflex action," which means specialization in force ; not transformation, but rather elec- tive action, separating the two forms of electric xorce ; otherwise, this also would be meaningless. Finally, that there is such transference of force — electric force — from the muscles and all the organs to the appellate nervous centres, would seem inevitable, from the very nature of things. Other- wise, the comprehensive arrangements for generating force would not be effective, and the maintenance of a balance utterly impossible, since every movement involves expendi- ture of force for producing it. One other thing in this connection, and we will bring the matter to a close ; namely, the very intimate relation which the terminal nerve trunks sustain to each other in the tissues (Fig. 216), which is not by inosculation, as Sir Charles Bell thought (the finer work attained by means of the microscope since then mak- ing this known), but the fibres overlapping simply, which has the effect of completely separating the currents, enabling the outgoing current to pass up the sensory nerves and the in-going down the other or motor nerves, without in- terference, passing readily in and out of the open end of the nerves through the terminal plates for collecting it. And it must not be supposed for an instant that the brain gene- rates the nervous force expended in the organism, though undoubtedly it contributes greatly to it ; but as in the case of the spinal centres, its principal role is the separator and 508 GENESIS OF NEEVOIS FOKCE. regulator of the nervous supply, and a> a great reservoir, giv- ing it out in the measure of the requirements. .But if con- stantly drawn upon for producing the voluntary actions, as, for example, in walking over uneven ground, where every move- Fig. 216.— Nerves of the Face, fifth and seventh pairs.— Sir Charles Bell. A, facial nerve : B, trunk of same, dissected off and pinned out ; C, branch of third division of fifth nerve joining the plexus of the facial ; D, masseteric branch of fifth nerve ; E, bucco-labial branch of fifth ; F, branch of fifth to muscles of lower jaw ; G, infra- orbital nerve ; H, mental nerve ; /, infra-trochlear nerve. ment is voluntary, or made directly from the brain, it speedily induces exhaustion, though the amount of work actually per- formed falls far short of that done upon even ground, where the movements are simply reflex, the brain itself but slightly GENESIS OF NERVOUS FORCE. 509 involved. In fine, the generation of force involves the evolu- tion of heat ; hence we must conclude that the main source of force in the organism must be in the muscles ; nor is it reason- able that the furnace should be in the brain, since nervous sub- stance can endure less heat than any other tissue, a few degrees of blood temperature above the normal amount promptly arresting its functions, inducing prostration, insensibility and death. But the nerves terminating in the muscles as they do, the neurilemma blending with the sarcolemma, the nerve-plates in contact with the muscle-plates, we can readily understand how force may be rapidly generated without heating the brain, which is far removed. The nerve cells being the most highly organized, we can readily understand the special arrangements that obtain respecting them and their relations to the rest of the organism. The matter needs looking into. But we may rest assured that everything is as it should be for con- serving the central nervous system, at once the seat of govern- ment and throne of the cell-brood. The question which obtrudes itself, Can force be evolved by oxidation in the tissues without producing corresponding heat % has deepest import, but by reason of the nature of the problem is difficult of solution. In nerve cells heat metamor- phosis into electrical force is probably instantaneous and more or less complete, else active mental processes would be fraught with peril, speedily bringing life to an end from destructive changes it would necessarily superinduce ; hence, we must con- clude that heat metamorphosis is more or less complete and instantaneous. But in muscle cells, etc , it is different ; here an amount of heat is evolved, which cannot be regulated in any other way than by bringing the blood rapidly to the body-surface for cooling, and promoting radiation and con- duction by means of diaphoresis and evaporation, at the same time reducing respiration arid circulation for diminishing the importations, as has already been fully set forth ; otherwise, all these arrangements would be meaningless. Moreover, it is susceptible of easy demonstration by simply inhibiting the due escape of heat from the body for maintaining a balance, which is promptly followed by fever and constitutional disturbance, and, if not relieved, would undoubtedly terminate fatally. 510 GENESIS OF NERVOUS FORCE. Indeed, one may be speedily aroused from deepest sleep by in- creasing the covering- upon Mm simply, the sensations distress- ful in the extreme, the imperious necessity and dominant thought to cool the blood, disrobing with all impetuosity. So, then, we must conclude that oxidation in the body-tissues necessarily involves evolution of heat, and that the arrange- ments spoken of for regulating temperature are the only means for maintaining a balance ; the only question being whether there is exception in nerve cells. For the reasons given, I thirk such is the case. While life is an "eddy" in force, the central nervous system is the heart of the eddy where force culminates, both generated in itself, and rushing into it through the nerves from every'portion of the body, for evolving the movements and producing the psychical phe- nomena, while the rapidity of THOUGHT would of itself show that metamorphosis is instantaneous. THE END. INDEX. PAGE. Abdomen, a ventricle 231 Abdominal sound 189 Acineta, action in 55 Actinosphaerum, action in 51 Air, atmospheric 1 molecular constitution of 2, 5 force for effecting suspension in space 7 mode of producing circulation in, bo as to form the currents in the earth 16, 17 in water 18 bones 90 in intestines 187 residual, functions of 123 Air-bladders in fishes 373 in birds 80, 435 Albumen, rapid absorption of 80, 216 Alveolar action 122 capillaries 123 action in 124 Amoebae-movement, import of. .... . 46, 51 mechanical principle for effecting the molecular movements in 447 Animal circulation, principle in 29, 32 Arteries, anatomy of 148 locomotion of 151 pyramids 153 progressive increase of the muscles in 152 development of 436 pulsations, force of 147 Arterial feeders to stomach 275 small intestines 276 large intestines 277 Arterial pressure and its relation to development 40, 41, 434 physiological problem connected with respiration 134 Arterialization of the blood and its rela- tion to development 41, 434 PAGE. Automatism in the vessels, shown in arterial tracings 138 Bile, mode of circulation 228 muscular force in 229 automatism in the gall-ducts 230 Bladder, urinary, action of 294 gall, action of 231 Blood, circulation of, in the alve- oli 121, 136 Brain, oscillations in 183 Branchiae in arenicola 387 terebella 389 fishes 333 Briinner's glands 209 Capillary action, automatism in. 160, 168 reflux impossible 154 Capillarity, principle in 19» Carbon, atomic weight 22- Carbonic acid, atomic weight 10> normal constituent of the blood. . . 362 function of, in digestion 363 in the nutritive processes 369 in respiration 367 not a poison 364 a food for the tissues 366 Cells, columnar, of intestines 217 Centre, thermic 356 rhythmic, for the womb 335 respiratory 32, 349 vaso-motor 33, 349 voluntary-motor 33, 349 Chorion, human (eighth week) 324 Circulation, primitive 52, 5$ in amoebae 46, 55 ditto, gastrula 56 ditto, worms 383 ground-plan of 380 planaria 381 leech 383 arenicola 387 terrebella 389 XX INDEX. PAGE. , Circulation, decapods 392 lobster 394 | oyster 397 fishes 399 chick 344 ditto, tissue-interstices 176 portal • • 185 hepatic 223 embryonic 316, 436 Coordination of internal and external parts 57, 60 applied to respiration and the ac- tion in the lungs 61, 65 mode of effecting it 67, 68 stomach and walls of the abdomen. 196 Correlation of nervous centres 32, 34 Crocodile connecting link with the birds 430 Curves, Traube's 137 blood-pressure 145 intrathoracic-pressure 134 Defecation, action in 309 Deglutition, action in 193 Diaphragm, office of 86, 91 adjustments in 239 action of the pillars 240 ■ ditto, vena cava lumen 243 action of, in defecation, etc 309 Dicrotism, source of 160 multiple 172 arrested 163 Diffusion, polar action in 20 Digestion, mechanical action in 204 Dualism in muscles 456 in nervous force 453, 503 Ductus venosus, occasion for 440 Eel, amphibious 407 Electrical force 7 source of 10 r61e of 7 producing circulation in the at- mosphere 15 producing circulation in the water. 16 producing, circulation in the plants 18, 19 tension in muscles 453 similarity with nervous force 452 generated in the tissues 448 Embryo, an acpiatic animal 318 human, third week 347 Emesis, action in 315 Erectile tissue, action in 484 Expansion, principle in 449 demonstrated 452, 490 PAGE. Expansion, the primary movement.449, 500 Fat, rapid absorption of 218 Fever, physiology of 253 therapeusis of 357 Floor to the viscera 84, 85, 300 Floral circulation, principle in 23, 27 Foetal circulation 442 Force, dualism in muscular and nerv- ous 444 Frog, circulation 416 respiration, principle in 62 Gall-ducts 230 Gases, functions in swim-bladders 373 genesis of 395 ditto, intestines 187, 362 ditto, stomach 203 Gastric capillaries 201 action 204 Gastrula, action in 56 Glands, peptic 198 mucous 200 Gullet, action of, in respiration 239 Hardness in muscles produced by nerv- ous force 461 ameasure of work 452 explanation for 453 Heart, principle in 126, 140 relation to the lungs 126 ditto tissues 153 special role in 378 beginning of cardial development. 389 great relative size of left cham- bers, explanation of 130 not the force in the circula- tion 174, 433 tracings deceptive 180 tymph, function of 260 embryonic 345 first evidence in terebella 389 in decapods 392 ditto lobsters 393 oyster 397 fishes 399 development of left auricle 412 peculiarities in perennibranchi- ates 415 in the frog 411 in chelonia 426 interventricular septum 428 in draco volans 429 in crocodile 430 in birds 435 Heat, proportion in solar beam 9 INDEX. XXI PAGE. Heat, metamorphosis of, into electrical force for energizing the polar forces. 10 producing circulation in air and water and living organisms 10, 22 effect upon the floral circulation . . 24 Intestines, transverse section of, in birds 187 ditto, mammals 187 import of the action in, or peris- talsis 208 physiological anatomy of 209 capillaries in 218 glands in 210 Iris, anatomy of 477 ■ physiological experiments upon. . . 479 Jaws, mode of opening and closing them 470 Kidneys, physiological anatomy of 290 ■ nerves of 293 ■ action in 296 Laughter, pumping action in 225 Law in the animal circulation 27 Leech, plan of the circulation in 385 no heart in 384 Lieberkuhn's glands 210 " Lines of force " (Faraday) 11 Liver, anatomy of 226 circulation in 227 Lungs, action in 92, 100 alveolar collections, mode of ex- pelling them 101, 102 lung-action demonstrated 109, 113 circulation of air in 92, 104 ditto, blood 121 a dual circulation in 35, 125 mode of effecting coordination 61 nascent condition 409 in chelonia 422 molded to the chest 114 Lung-action absolutely necessary 99 Lymphatics, automatism in 248 physiological anatomy 250 vessels of 252 muscles 253 valves 254 commencement of lacfceals 255 muscles in 257, 258 mechanical action in the walls of intestine 256 force in the abdomen for increas- ing the action 259 hearts, automatic action in 260 Magnetism, terrestrial 14, 15 PAGE. Magnetism, atmospheric 15, 16 involved in polar action 7 molecular movements in cells 447 increased by electricity 453 Mesentery 299 action in 298 position in quadrupeds 85 ditto, man 300 floor of support to 84, 301 Mucous foldings in bronchia, indica- tions of 101 Muscles, external oblique, action in 302 internal oblique, ditto 307, 308 transversales, ditto 305 rectus abdominis 305, 315 levator ani, office of 312 of the tortoise 421 cause of the hardness in, during action 453 stomach 206 intestines 101 levator palpabrae 484 orbicularis oris 480 palpabrarum 484 penis 485 Nerves, recurrent laryngeal, unique distribution accounted for 118 "inhibitor" and "accelerator," physiology of 131, 283 to the capillaries 133, 166 ditto, cell-brood ". . 178, 179 to the viscera in the abdomen 263 correlation of nervous force in . . . 264 of Meissner 265, 272 ■ ditto, Auerbach Ibid. ditto, columnar epithelium. . 266, 270 double ganglionic chain 278, 288 roots of spinal nerves and dorsal ganglia 279 vaso-dilator and contractor 281 ditto, demonstrated 282 pneumogastric, action in 284, 2S5 — — extensive distribution of 286, 287 splanchnic 288, 289 to the walls of the abdomen 313 ditto, gravid womb 333 respiratory, in fishes 401, 406 leech 59 dualism in 444, 503 New-born, changes produced by birth . 338 Nitrogen gas, functions of in the or- gans 370 Nutrition, principle in 28 xxn INDEX. PAGE. Nutrition, rapidity of, in plants 27 difference in the nutritive proc- esses and the generation of force. . 27, 2S in the embryo 440 below the diaphragm 439 Odor, f aecal, source of 3 < 1 Osmose, principle in 20, 21 Ovum, human 348 rabbit 323 mole 348 air-chamber in 341 physiology of the circulation in the chick. 343 Oxidation, seat of 359 Oxygen and nutrition 439 Oyster, physiological experiment upon. 468 Pancreas, action in 231 Pelvic viscera, concentrating force in.. 309 Penis, anatomy of 485 action in 487 Perineum, floor of 312 Perennibranchiates, circulation in 415 Physiological problem connected with the curves of blood-pressur* and intra- thoracic pressure curves 134 Placental souffle, analogue of respira- tion 319 villi, physiological anatomy of — 326 sinuses 327 Pleuretic adhesions 97 Pneumatic ducts 374 Pneumonia, mode of expelling collec- tions 101 Polar force 6 mode of energizing polar force 7 action in the atmosphere 11, 14 action in the water 18, 20 action in diffusion 20 action in osmose 21 action in capillarity 21, 22 action in floral circulation 23, 25 action in nutrition 27 energy of in flora 25, 26 Portal circulation, physiological experi- ments in 222 dependence upon respiration 69 Pressure, its relation to circulation. . 16, 17 mechanics for effecting changes in pressure in the atmosphere 15 ditto in animal organisms 29, 31 arterial, relation to animal move- ment 40, 127, 156, 429 fundamental in the body 43, 45 PAGE. Pressure in the abdomen 189 Pulsation, first visible in the vessels 379 Pulsus venosus 128 Respiration, mechanical principle in 35,36 relation to venous system 37, 38 animal movement 28, 497 ditto body-temperature 355 two respiratory movements per- forming at the same time; notably, one in the lungs, the other in the tis- sues 39 in different stages in develop- ment 47 frog 62,65 bird 72 mammalia 83 in the tissues 160 suspension of, in deglutition 191 effect upon the portal circula- tion 70, 220 in perennibranchiates 418 ditto chelonia 419 axolotl 412 fishes 405 subaquatic 65, 424 Respiratory plane ... 303 rocking in the body 90 Rete mirabile, office of 377 Rhythmic centre for the vessels 136 lymphatics 248 Sacral promontory, explanation for 301 Sacrum, floor to pelvis 311 Sighing, physiology of 224 Sleep, physiology of 369 Spleen, anatomy of 233 action in 235 vein, action in 245 Stoma :h and walls of the abdomen co- ordinated 196 transverse section of, showing mucous fold 197 physiological anatomy of ... . 198, 202 gases, secretion of 203 m3chanical action 205 muscles of 206 leech 386 Sun, source of electrical supply 10 producing molecular action in the atmosphere 8, 18 ditto water 19, 20 ditto plants 23, 26 Temperature, body 349 IJSDEX. XXHL PAGE. Temperature, genesis of 350 relation to musculation 351 mode of maintaining a balance. . . 352 Terebella, plan of the circulation in, . . 390 Thermic centre 350 Tidal air 98 Tissues, respiration in 160 Tissue-circulation, force in 170 Tongue of frog 134 chameleon 486 Trachea, functions in 104, 108 physiological experiments on. 116, 117 action in vocalization 120 Tracings, arterial 140 artificial, produced by apparatus of Marey 141 blood pressure 145 Umbilical cord, pulsations in 147 Uterine sinuses, pumping action in. . 326 vessels 332 centre of reflex action 336 contents, mode of expelling 337 Uterus, physiological anatomy of 322 impregnated 323 Uterus and placenta, section of 325 Vacuoles, action in 52 Valves, tricuspid, insufficiency of jl«» absence of in portal system 237 lymph 254 Vas deferens 492 PAGE. Vasiculae seminales 496 Vaso-dilator nerves 277 Vaso-contractor nerves 278 Veins, physiological anatomy of 244 Vense cavae, anatomy of 244 adjustments in inferior 243 ditto, superior 244 mode of termination at the heart. 436 elongation and contraction of 245 Venous ostia, great relative size of . . . . 129 system, action in 183 Vessels, local action in 155 maternal, action in 334 changes produced by birth 438 automatism in 139 nervous supply 157 Villi, anatomy of 213 Viscera of the tortoise 426 Vital force, nature of 445 Vocalization, principle in 118, 120 Walls of the abdomen, section of 315 Water, action in 18 composition of 18 in perpetual motion from changes in polarity 19 mechanics in evaporation and dif- rusion 20 Waves, respiratory in blood-pressure.. 134 arrested 173 Work, a measure of force 452