The red globules are vesicles having a distinct homogeneous envelop, which incloses a central mass of whitish albuminous matter, and a surrounding film of red fluid. Their form is circular and biconcave, they present therefore cupped surfaces and an 8-shaped edge. They readily distend themselves by endosmosis with thinner fluid and assume a spherical shape. On sudden pressure being applied, and sometimes Fig. 1.

Fig. 2.

from other causes, they assume a kind of crenate form, conveying the idea that the central mass, the so-called globulin, is broken up into a number of granules, pushing irregularly outwards the homogeneous envelop. The white corpuscles are much larger, nearly double the size of the colored ones; they are spherical, and may often be seen when a drop of blood is examined under the microscope, remaining motionless and fixed in the field, while the red globules are hurried along on all sides round them by the currents which are created in the fluid by capillary attraction. No true nucleus can be seen in the white corpuscles; they seem to consist of a semi-solid mass of albuminous matter, inclosed within a delicate envelop. Their function is not certainly known; by some physiologists they are regarded as constituting, together with the similar corpuscles in the lymph and chyle, transitional forms in the development of the red particles. By others, they are supposed to be the agent in the formation of the fibrin, which they elaborate out of the albumen, imparting to it its peculiar coagulating and so-called plastic properties. The use of the red globules is in all probability connected with the function of respiration; this seems wellnigh demonstrated by the facts of comparative anatomy, and by the marked changes which they undergo in the course of the circulation. Liebig has expressed the opinion that they are the carriers of oxygen to the various tissues, or, more exactly, the iron which they contain; this element in its protoxide form receiving in the lungs another atom of oxygen, and thereby passing into the state of peroxide, while in the course of the circulation it again parts with the atom of oxygen in exchange for one of carbonic acid, and thus passes into the state of protocarbonate. This view may be in part true, but is doubtless too exclusive; there is as much reason to suppose the Liquor Sanguinis to be the vehicle of the oxygen and carbonic acid, as the red corpuscles.

1 Acetic acid brings into view, or produces one, two, or three granules similar to those contained in the pus cell.

Mr. Wharton Jones believes that the red globules elaborate the fibrin, or rather are transformed into it, bursting and dissolving like secreting cells. Various plausible arguments have been advanced in support of this view, which was first propounded by Dr. Simon, of Berlin, and is adopted also by Wagner and Henle; but it does not appear to the writer that it can be considered at all established. Neither on the other hand can Dr. Carpenter's be considered proved, though the preponderance of testimony seems on the whole to be in its favor; nor is there, in short, any positive cause to forbid us to believe that the truth may lie intermediate, and that the production of fibrin may be one result of the general cell growth taking place in the blood. With respect to the red globules, however, this is certainly proved, that their amount is, ceteris paribus, proportionate to the vigor, health, and strength of the individual. In the examinations made by MM. Andral, Gavarret, and Delafond, of the blood of various animals, it was constantly observed that those which possessed most strength and vigor, and were generally the finest specimens of the race, gave the highest figures in a series showing the relative amounts of globules; while those that were debilitated and poor showed a corresponding deficiency in this particular. Also, when the breed of a species was improved by crossing it with another, there was a corresponding increase in the quantity of red particles. In the human subject, the comparison of the general vigor and activity of the sanguine temperament, both as regards body and mind, with the sluggishness and dulness of the lymphatic temperament, or with the languor and debility of the anemic patient, show that the same rule holds good. In Prevost's and Dumas's experiments, animals near death from loss of blood, were recovered by an injection into their veins of a mixture of red particles and serum. serum alone had not this effect. The proportion of red globules dried to 1000 parts of blood, is in healthy males estimated at 127 parts by Andral and Gavarret; lower and higher figures have been given by other analysts, but this probably is the result of somewhat different modes of proceeding. In females the proportion of globules is lower, Becquerel and Rodier make the difference to be about 15 parts per 1000. The blood of the foetus appears to contain an unusually large amount of globules, stated by Denis in the proportion of 222 to 140 of maternal; after birth this gradually diminishes. Plethora is the chief pathological condition in which an increase of red globules has been observed. One of the cases of cerebral congestion mentioned by Andral presented an amount of 138, 6 parts per 1000, an excess of 11 above the normal figure; after venesection, the globules in this case were so far diminished that the quantity only amounted to 101, 1 per 1000, considerably below the mean. In various febrile diseases, an augmentation of the globules has also been observed; thus, in the period immediately preceding the outbreak of continued fever, their amount was once found as high as 157.7; in the early period of a case of severe inflammatory fever, the fourth day of the disease, the globules had attained the extraordinary height of 185 parts per 1000, the greatest amount ever observed; in several cases of typhoid fever (fever with intestinal complication) the globules had risen to 142 or even 149, and

The

even on the second bleeding were found still considerably above the mean; in scarlatina and in measles an increase in the amount of globules was also found, the maximum (which existed in the latter) being as much as 146. No increase was observed in cases of variola or of modified smallpox. The condition of the general system coexisting with, and probably occasioned by, the increase in the amount of red globules is exaltation of the animal heat, heightened sensibility, and muscular irritability; the spirits are high, and the mental energy great, the pulse beats full and firm, the power of resistance to debilitating and morbid influences is considerable, the tendency in disease is to active inflammation and high febrile excitement, and bleeding, if employed, is well borne. Probably, a chief cause of danger when the amount of red globules is considerably increased, is the simultaneous diminution, or at least non-proportionate increase of the fibrin; hence arises a liability to serious hemorrhages in the brain or other parts. The effect of iron in promoting an increase of the red globules is well known, but it will often fail where the attendant circumstances are unfavorable, and we have seen a much more rapid effect produced by the change from a scanty to an ample diet. Free exposure to fresh air and light seems also powerfully to promote the formation of red blood, as much as the deprivation of them tends to destroy it. The opposite condition to plethora, for which the term spanemia (oravos, scarce) is more appropriate than anemia, is essentially characterized by a deficiency in red globules. Extreme cases of this state are by no means unfrequent, and, which is not sufficiently known, are by no means unattended with serious danger. Sudden death has in several instances taken place apparently from the cessation of the heart's action, the debilitated organ being insufficiently stimulated by the impoverished blood. In an extreme case of chlorosis, Andral found the globules at so low an amount as 38.7 per 1000, the water at the same time being increased from 790 to 868.7. Similar alterations were found in the blood of other individuals who had become anemic from other causes, from lead poisoning, the cancerous or tuberculous cachexia. In Bright's disease, there is evidently a marked failure in the power of producing red globules, and the same is the case in the peculiar affection termed leucocythemia, which either depends on, or is coincident with, great hypertrophy of the spleen. We are inclined to think that in spanemic states the red globules are not only deficient in number, but defective in quality; they appear under the microscope manifestly paler than those of persons who have a healthy color, their hæmatin, in all probability, is not properly formed. The well-known symptoms of this condition are general debility, diminished temperature, palpitation, often excessive, of the heart, and various nervous affections. In some of the most malignant fevers the blood-globules appear to be actually destroyed; Dr. Williams has observed this in a case of albuminuria, proving fatal by purulent infection, and in a case of malignant scarlatina; we have examined the blood a few times in persons dying of such diseases, but have not found any noticeable alteration in the globules. Rokitansky mentions that he has observed in a septic state of the blood an altered condition of the globules, which are swollen up from their natural disk-like shape, and have parted with much of their

hæmatin to the surrounding fluid. The red globules, as has been mentioned, are very liable to be affected by the fluid in which they float; when this is dilute, they distend themselves by endosmosis, and become spherical, while the mass at the same time assumes a dark red color. By the addition, however, of concentrated saline solutions, the bright red color is again restored, and the corpuscles again assume their biconcave form. When carbonic acid is added to arterial blood, the corpuscles change their biconcave for the biconvex form,' and the color at the same time changes from red to black. On these facts, Scherer and Nasse maintain the theory that the alteration of color in the blood which is effected in the lungs, depends upon an alteration in the form of the corpuscles, the biconcave disks acting as concave mirrors, which collect the reflected rays instead of dispersing them as convex surfaces do. Whether this theory be true or not, the facts it records are certainly worth remembering, as a distended state of the corpuscles, by whatever cause occasioned, must greatly increase the liability to the occurrence of local congestions. When the fluid in which the corpuscles float is more aqueous than natural, the red fluid which they contain passes out of them by exosmosis, and mingles with the serum. When this is the case, the walls of the vessels, and the tissues in immediate contact with them, very commonly become saturated with a red color, which must be carefully distinguished from that which accompanies inflammation. The effect of diluting the Liquor Sanguinis upon the blood-globules is exceedingly well shown by an experiment performed by Mr. Lane. An animal was bled, and the serum, after the formation of the clot, was, as usual, colorless, or of a light yellow; a certain quantity of matter was then injected into the veins, and soon after blood was again drawn. The serum of this, however, was of a decided red, contrasting strongly. with that of the preceding quantity. It was, therefore, quite clear, that the hæmatin had been removed from the globules, and dissolved in the serum. We have observed the same thing with the microscope in the blood of frogs, and in that of foetal vertebrata. When the globules have not been exposed to the action of water, or only in a slight degree, the space between the envelop and the nucleus is filled with red fluid, which almost or entirely conceals the latter; but when water has been freely added, the red fluid entirely disappears, and the nucleus comes clearly into view. It seems very probable, as Dr. Williams suggests, that the instances of sudden death occurring immediately after copious draughts of cold water in an exhausted state of the system, have been in some measure owing to such alterations of the blood-globules, as we have just noticed. The same changes may also be concerned in the phenomena consequent on excessive losses of blood, especially in occasioning the local congestions which are apt to take place in them, and in the anemic generally. The red globules of human blood exhibit a tendency to cohere together in such a manner as to form tolerably regular piles, or rouleaux; in the healthy condition the cohesion soon. ceases, and is not nearly so strongly manifested as in the inflammatory state. Of this, indeed, it is quite characteristic that the globules form

The authors of the Physiological Anatomy, however, do not confirm this statement.

Fig. 3.

rows of some length, made up of numerous disks cohering together by their surfaces, and having their edges disposed so as to form a tolerably straight line. The cause of this tendency is not certainly ascertained, but the phenomenon seems to give some countenance to the opinion of Mulder, that the red corpuscles become invested in the lungs with a film of oxidized protein matter, which is found more abundantly in inflammation, and may cause the adhesion of the particles to each other. There must, however, be some further reason why the disks should so exactly adapt themselves to each other face to face.

diameters.

While so much uncertainty prevails respecting the origin of the red corpuscle, it is not possible to point to any foregoing condition as specially tending to promote their growth and increase, or to occasion their atrophy. All that can be said is, that a proper constitution of the Liquor Sanguinis is certainly essential, as being the material out of which these floating cells are nourished and built up. If this be impoverished, or otherwise deteriorated, the corpuscles will not be properly developed; and again, by improving the quality of their plasma, their healthy condition will be restored. Of this, we have a good example in those cases of chlorosis, where the administration of iron is sufficient to reproduce the ruddy hue of the complexion. In other cases, a defective state of nervous influence, proceeding from some mental affection, occasions the atrophy of the red particles; but we cannot tell whether this cause acts upon them primarily, or, as is more probable, through the medium of other organs and functions. There can be no doubt that the blood-globules have an appointed period of existence, after which they naturally decay. This decay probably takes place in the general course of the circulation, at least in part. Evidence, however, has recently been adduced to show, that the spleen is especially the seat of a destructive process, affecting the globules; and that the yellow pigment matter, so frequently found in this organ, is, in fact, the remains of their altered hæmatin. In the liver, also, the bloodglobules seem to yield up their coloring matter, to furnish the yellow pigment of the bile; and the coloring matter of the urine is no doubt derived from the same source. The circumstance that so much pigmentary matter should, by these two channels, be ejected out of the system, shows, on the supposition that it is derived from that of the red globules, how rapidly the latter must undergo decay; and, by consequence, how fast their reproduction must take place. It is worth remarking, that one drug, the most commonly used, perhaps, of all, seems to have almost as much tendency to cause the destruction of red corpuscles, as iron has to promote their formation. This is mercury, under a course of which, as Dr. Watson mentions, a patient was blanched as white as a lily, who previously had a complexion compounded of the rose and the violet. The non-depuration of the blood mass exerts an injurious influence upon the development of the red globules, as well as upon its other constituents. The effect of some