4. Issue In Death

Diseases are mortal for the most part,

(a.) Through exhaustion of power and of organic matter, tabescence, loss of fluids.

(b.) Through the suspended function of organs essential to life; through palsy; through sudden and extensive displacements; through hypertrophy, atrophy, diseases of texture.

(c.) Through vitiation of the blood and palsy of the nervous centres arising out of the conflict between contaminated blood and nervous medulla.

XIII. Where Several Diseases Coexist In An Individual

Where Several Diseases Coexist In An Individual, they are in part primary, in part secondary and subordinate to, although homologous with, the former. Again, they are partly sequelae and residua of antecedent disease, as in the case of atrophy of the brain consequent upon apoplexy, upon encephalitis.

XIV. Very Dissimilar Anomalies

Very Dissimilar Anomalies may coexist in one individual, as mere local affections or complications. Combination or exclusion result only in the case of heterogeneous diseases founded in or determining a dyscrasis: for example, cancer and tubercle, organic heart disease and tuberculosis. The study of these two relations opens a rich field of promise for the furtherance of accuracy in diagnosis.

XV. The Import Of A Disease

The Import Of A Disease bears a direct ratio to the worth of the organs attacked: take, for example, hypertrophy in different muscular organs.

XVI. With Reference To The Period During Which Anomalies Originate

With Reference To The Period During Which Anomalies Originate, we have to distinguish congenital, or such as have become established during intra-uterine life, and acquired, or such as have arisen during extra-uterine life. The former comprehend primitive anomalies.

XVII. Primitive Anomalies

Primitive Anomalies comprise malformations. These are deviations of the organism, or of an organ, so intimately blended with its primary development, as to occur only at the earliest periods of embryonic life, or at any rate before that of mature foetal existence.

Malformations, when inconsiderable and harmless to the individual, are termed lusus naturae, variation, defect of formation, malformation; when more marked, deformity; when excessive, misbirth, monstrosity, monster.

Despite some progress made in this field of late years, the genesis of malformation is still veiled in much obscurity. The opinions of modern physiologists on this point may be collected under two heads. According to the one section, the malformations are referable to a primitive malformation of the germ. According to the other, to various influences affecting the germ in the progress of development.

The former opinion resolves itself into that of the ovists and that of the spermatists. Those believed in the foreshadowing of the malformation in the ovum; these regarded it as dependent upon the spermatozoa as embryones.

At this day both theories are rejected as inapplicable to a vast number of malformations which unquestionably do originate during the development of the germ. Still the malformation might be founded in the nature of the ovum and of the sperma, although neither of these constitutes the embryo. The frequent recurrence of the same malformations out of the same parents, and the hereditary character of these anomalies, render this not improbable. We might further advert to the nature of certain malformations - inversions, duplicate formations, for instance - in which the fusion of two germs, and the bisection of a single germ, during their development, are neither of them quite conceivable.

The second of the aforesaid propositions embraces several hypotheses.

(a.) The oldest and most popular attributes the malformation to a sudden and forcible impression wrought upon the mother (Verschen). The question whether mental emotions do influence the development of the embryo must be answered in the affirmative. Instances undoubtedly have occurred of such maternal impressions - fright more particularly - when violent, giving rise to malformations. Seeing that many malformations originate in an arrest of development, and how frequently the former bear a certain resemblance to various animals, it is just conceivable that the development of the embryo may be so arrested by maternal emotions as accidentally to occasion a likeness between the object that produced the impression and the resulting malformation.

(b.) A second doctrine derives malformation from external mechanical influences, such as a blow, a thrust, a fall, etc, suffered by the mother; mechanical obstacles to the passage of the ovum through the Fallopian tubes, and to its growth in the womb; excess or deficiency of liquor amnii; restriction of space for the foetus; the formation of false membranes within the cavity of the amnion, etc. Although F. Meckel dissents from this doctrine, we are not quite prepared to relinquish it ourselves.

(c.) A third opinion assigns, as the cause of malformations, disease of the foetus.

Disease arrests the development of foetal formation with respect to growth, shape, position, and texture of particular organs, indirectly embarrassing the expansion of neighboring organs, or, it may be, causing their destruction. A common disease having this tendency is dropsy, as preventive of union or closure, and productive of disjunction or fissure. Inflammation and its consequences may be mentioned under the same head.

The conditions of encephalocele, of hemicephalus, of anencephalus, and of spina bifida, being obviously due to dropsy, are beyond the pale of arrested formation. Certain anomalies of the peritoneum and of its viscera, formerly reckoned as genuine instances of arrested formation, have been shown by Simpson in certain instances probably to result from foetal inflammation. Some malformations of the heart, especially defects in its septa, we hold to be owing to foetal endocarditis, and to consequent coarctation of the heart's orifices.