ness of a tissue gradually disappears through the development of granulations, and during suppuration. However different therefore these processes of destruction apparently are from the processes of growth, at a certain point nevertheless they entirely coincide. There is a stage, when it is impossible to decide with certainty, whether we have in a part to deal with simple processes of growth, or with the development of a heteroplastic, destructive form.

This mode of development, which I have just described to you, is not, however, in any way peculiar to pus alone, but characterizes every heteroplastic formation; the first changes which we have shown to take place are found occurring in exactly the same manner in heteroplasms of every sort up to the most extreme and malignant forms. The first development of cancer, of cancroid and of sarcoma exhibits

FIG. 138.

the same stages; if the course of their development be traced sufficiently far back, we at last always come across a stage, in which, in the younger and deeper layers, indifferent cells are met with, which do not until a later period, according to the particular nature of the irritation to which they are exposed, assume the one or the other type. We may therefore, taking new-formations in general,

Fig. 138. Development of cancer from connective tissue in carcinoma of the breast. a. Connective-tissue corpuscles, b, division of the nuclei, c, division of the cells, d, accumulation of the cells in rows, e, enlargement of the young cells and formation of the groups of cells1 (foci-Zellenheerde) which fill the alveoli of cancer, f, further enlargement of the cells and the groups. g. The same developmental process seen in transverse section. 300 diameters.

1 When these groups of cells fall out, the alveoli (loculi) of cancer appear, the relation of the group to the alveolus being the same as that of the bone-cell to the lacuna. From a MS. note by the Author.

DURATION OF LIFE OF INDIVIDUAL ELEMENTS. 455

consider the history of the greater number, and especially of those which principally consist of cells, from an entirely similar point of view. The form of ulceration which is presented by cancer in its latest stages, bears so great a resemblance to suppurative ulceration, that the two things have long since been compared, and quite in the olden time a parallel was drawn between the eroding form of suppuration, or chancre, and the suppuration," or sanious ulceration' (Verjauchung) of

cancer.

But there are essential differences between the individual species of new-formations in consequence of their elements... attaining to very different degrees of development, or to express myself otherwise, in consequence of the length of time their elements are calculated to last-the average duration of the life of the individual elements-being extremely different. We know, that if we examine a spot a month after suppuration has taken place in it, although the pus is apparently still present, we can no longer rely upon finding unaltered pus in the collection. in the collection. Pus which has lain anywhere for weeks and months is, strictly speaking, no longer pus, but disintegrated matter, débris, dissolving particles of pus which have become altered by fatty degeneration, putrefying processes, calcareous deposits and the like. On the contrary we find that a cancerous tumour may last for months, yet still contain the whole of its elements intact. We can therefore positively affirm, that a cancer-cell is capable of existing longer than a pus-corpuscle, just as we know that the thyroid body exists longer than the thymus gland, and that certain organs, for example

1 Jauche (sanies) always conveys the idea of decomposition. We call Mistjauche the fluid obtained by the maceration of manure. Verjauchung is the process during which the substances are decomposed which subsequently furnish the Jauche. The French putrilage is nearly equivalent to Jauche in its pathological acceptation, only the latter is rather thinner and more liquid. From a MS. note by the Author.

individual parts of the sexual organs, early perish in the course of ordinary life, whilst others retain their existence throughout the whole of life. So it is also with pathological new-formations. At a time when certain forms have long since entered upon their course of retrogressive metamorphosis, others are only just beginning to attain their full development. In the case of many new-formations, retrograde metamorphosis begins comparatively so early, nay constitutes to such a degree what is ordinarily met with, that the best investigators have looked upon its different stages as the really characteristic ones. In the case of tubercle, for example, we find, that the majority of all modern observers who have made it their professed study, have taken its stage of retrograde metamorphosis for the really typical one, and that inferences have hence been drawn with regard to the nature of the whole process, which with equal right might have been drawn with regard to the different stages of the retrograde metamorphosis of pus and cancer.

We are as yet able in the case of very few elements to give in numbers with absolute certainty the average length of their life. There manifestly exist variations similar to those we meet with in normal organs. But among all pathological new-formations with fluid intercellular substance there is not a single one, which is able to preserve its existence for any length of time, not a single one, whose elements can become permanent constituents of the body, or exist as long as the individual. This may no doubt seem doubtful, because many forms of malignant tumours subsist for many years, and the individual retains them from the time of their development until his death which may perhaps occur at a very advanced age. But the tumour as a whole must be distinguished from its individual parts. In a cancerous tumour which lasts for many years, the same elements do not last the whole time, but within

COMPOUND NATURE OF TUMOURS.

457

2

its limits there occurs a frequently very numerous succession of fresh formations. The first development of a tumour takes place at a definite point, but its subsequent growth does not consist in the production of a constant succession of new formations from this point, and in the occurrence there of an intus-susception (absorption) of material, by means of which the existing parts enlarge and so the whole tumour grows. On the contrary around the original focus1 (Heerd), little new foci are formed, which, increasing in size, group themselves around the first, and so gradually give rise to a continually progressing enlargement of the existing tuber. If the tuber is seated on the surface, we find on section a semicircular zone of the most recently formed matter, at its periphery; if it is in the middle of an organ, the newly apposed foci form a spherical cortex around the older centre. If we examine a tumour after it has existed perhaps a year, it usually turns out that the elements first formed no longer exist in the centre. There we find the elements disintegrating, dissolved by fatty changes. the tumour is seated on a surface, it often presents in the centre of its most prominent part a navel-shaped depression, and the portions immediately under this display a dense cicatrix which no longer bears the original character of the new-formation. These retrograde forms I have described as occurring in cancer, especially in the liver, lungs and intestines, where they are not unfrequently met with, and can be readily demonstrated.

If

It is always possible to convince oneself, that, what is called a tumour, constitutes a conglomerate mass, often extraordinarily large, made up of a number of little miliary foci (lobules), of which every single one must be referred to

1 Focus here signifies the first rudiment of a tumour, produced by the proliferation of a limited group of cells. See note on Heerd, p. 341.—From a MS. note by the Author.

Tuber tuberous tumour. See note, p. 427.

a single or a few parent elements.

Inasmuch as the forma

tions progress in this manner, no matter whether they consist of pus, tubercle or cancer, new young zones are being constantly added on to the old ones, and we may, if we intend to trace the course of development, calculate with great certainty upon always finding the young parts at the extreme circumference, the old ones always in the centre. But the zone produced at the latest period of the disease extends to a considerable distance beyond the zone of degeneration that can be discerned by the naked eye. If we examine any proliferating tumour of a cellular character, we often find, three to five lines beyond its apparent limits, the tissues already in a state of disease, and exhibiting the first traces of a new zone. This is the chief source of local recurrence after extirpation, for it proceeds from the zone that cannot be detected by the naked eye beginning to grow, in consequence of the increased supply of nutritive material which results from the removal of the original tumour. No new deposit from the blood takes place there, but the new-formed germs, which already lie in the neighbouring tissue, run through their further development in the same manner that it would otherwise have taken place, or perhaps, even still more quickly.

This fact I regard as extremely important because it shews us that all these formations have essentially a contagious character. As long as it was imagined, that the mass once formed increased only by the growth of its constituents, it would of course look as if all one had to do for the purpose of getting rid of it was merely to cut off from the tumour all further supply of material. But there is manifestly a contagious matter formed in the tumour itself, and when the cells, which are in its immediate neighbourhood and are connected by anastomoses with the diseased cells, likewise enter upon the heterologous proliferation, it is impossible, I think, to come to any other