so in an actinomycotic focus giant cells are often seen. The blood vessels in the immediate vicinity of the focus are but rarely obliterated.

All the actinomycotic lesions may be divided into two great classes:

(1.) the neoplastic type, which is the one usually found in horses and cattle, and

(2.) the inflammatory type, which is the one usually found in man and hogs.

The neoplastic type of lesion usually occurs in very vascular tissues which are capable of an intense reaction and which often result in the production of a fairly-well defined indurated area clinically resembling sarcoma. The neoplastic type represents an attenuated form of the disease which does not possess marked invasive properties and is the form in which spontaneous recovery not infrequently occurs, the granulation tissue tumor representing nature's method of overcoming the infection.

In the inflammatory type the process of destruction exceeds in rapidity and intensity that of defense. The process tends to extend through the connective tissues and avoids, so far as possible, parenchymatous tissue, in which opposition to extension seems to be more vigorous. The inflammatory type tends to the production of sinuses but does not tend to the development of large abscess cavities which are usually the result of a secondary infection. The rapidity of development, as well as the nature of the lesion, depend more upon the differences in resistance manifested by the tissues than upon the initial virulence of the parasite.

The muscles are not favorable sites for the development of actinomycotic foci, probably because of the small amount of connective tissue present. The bones, too, afford a very unfavorable medium for the development or extension of the process.

The tendency to the formation of fistulous passages is quite characteristic. The discharge from these fistulae may present marked differences. In some instances it is serous, in others sero-purulent, and in still others distinctly purulent. The discharge usually contains the actinomycotic granules in varying number.

If the case has existed a considerable

To Illustrate the Article by Dr. Vander Veer and Dr. Elting, on a "Resume of the Subject of Actinomycosis with Report of a Case

period of time and shows evidences of improvement it may be difficult to find the characteristic granules. In fistulous cases secondary infection practically always exists.

Another of the characteristic features of actinomycotic lesions is the tendency to extend by continuity, rather than by metastasis. Metastasis does, however, often occur and usually takes place through the blood channels. Metastasis through the lymphatic channels is of very rare occurrence and involvment of the regional lymphatic glands is also rare unless secondary infection has supervened.

Poncet and Berard propose a division of actinomycotic infections into the following groups:

(1.) cervico-facial; (2.) thoracic; (3.) abdominal; (4.) cutaneous. Foci in bone, the spinal column, the genito-urinary organs, the brain, special organs of sense, etc., are regarded as complications.

From a considerable number of statistics it would appear that about fifty-five per cent. of the cases were of the cervicofacial type; about twenty per cent. of the thoracic and pulmonary type; about twenty per cent. of the abdominal type and about five per cent. of a variety of types.

In the abdomen, actinomycosis involves primarily only a single group of organs, i. e., the gastro-intestinal tract. There has never been a definitely authenticated case of primary abdominal actinomycosis reported which had not originated from the gastro-intestinal tract. There is no microorganism which can cause such extensive destruction of the abdominal viscera as the actinomyces. This results partly from the slow extension of the process allowing the formation of extensive adhesions, and partly from the opportunities afforded for the development of a secondary infection. Adhesions and abscesses then are the characteristic features of abdominal actinomycosis, the abscesses always resulting from a secondary infection.

The actinomyces gains access to the stomach along with the food, either animal or vegetable, most commonly the latter. Neither the gastric juice or the bile appear to have any very decidedly harmful effect upon the fungus.

The different portions of the alimentary tract seem to be affected in direct proportion to the length of time which the

intestinal contents remain in the different parts. For the development of an actinomycotic focus it would seem necessary to assume the existence of some lesion, however slight, of the mucosa. Once having penetrated the mucosa two modes of progression of the fungus are possible, first, a superficial involvement of the mucosa or secondly a penetration into the deeper structures without leaving behind any demonstrable defect of the mucosa. The latter mode of progression explains why with the extensive involvement of the abdominal viscera it is frequently impossible to locate the portal of entry.

Intestinal actinomycosis appears first as a small nodule in the submucosa which undergoes degeneration at its centre and presently gives rise to a small ulcer with undermined edges, which may extend either by progression or by confluence of several small ulcers. The base of the ulcer presents a granulating surface dotted with the characteristic granules and the mucosa about the ulcer is reddened. In certain instances the ulcers heal leaving irregular pigmented scars. It is very rarely that these early lesions are seen and they have been best described by Chiari. As the process extends there is a decided tendency for the involved portion of the intestine to become adherent to other portions of the intestine, the abdominal viscera or the abdominal wall. The extensive and widespread adhesions prevent, in most instances, a perforation into the general peritoneal cavity. When the pro

cess originates from the colon, i. e., from a portion of the intestine not provided with a mesentery, a retroperitoneal abscess is not an uncommon complication. This involvement of the retroperitoneal tissues may extend from the cul-de-sac of Douglas to the diaphragm, denuding the vertebral column, attacking the kidneys, liver and other viscera, and in some instances extending even through the diaphragm into the pleural cavity. The usual outlet in such cases is either through the ischio-rectal fossa or the pleural cavity into the intercostal

spaces or a bronchus. Most peri-anal actinomycotic fistulae

are of this origin.

If the process originates from the small intestine, caecum or appendix the tendency is for the disease to attack the anterior abdominal wall, which is by no means an uncommon