marked disproportion between the resisting power of the individual and the strength of the pathological agent producing the anemic state-a disproportion shown by an inability of the bonemarrow to generate a sufficient number of red-blood cells to supply the deficiency. Bunting next discusses the various possible ways in which anemia may be produced, especially in reference to this disease "first by insufficient blood formation, second by excessive loss of red-blood cells from the circulation, third by excessive destruction of red cells, and fourth by a combination of the preceding factors or any two of them." The author discusses each of these questions at length in regard to pernicious anemia, and from this concludes that pernicious anemia is probably due to "the absorption of a toxic substance, probably of intestinal origin, which acts on the circulating blood, producing hemolysis, and through the circulation also on the marrow, resulting in a faulty hyperplasia," the symmetrical lesions found at times in the spinal cord being another evidence in favor of a circulating toxine. Bunting then gives in some detail the results of an extremely interesting series of experiments with myelotoxic and hemolytic sera, and more recently with ricin, a soluble toxalbumen from the castor-oil bean, which has a marked toxic effect upon the leucocytes and red-blood cells of the rabbit, the species of animal used in these experiments. He also carried on a series of experiments on the effect of bleeding upon the circulating blood and upon the marrow. The conclusions which he draws from his experiments are "that in hemorrhage there is created a deficiency in circulating red cells, which is met by the marrow with the mature red cells lying close to the capillaries at the periphery of the erythrogenetic groups. In large hemorrhages, with exhaustion of the supply of mature red cells, a certain number of normoblasts are called out to supply the deficiency. On the other hand, with a circulating toxine, there is destruction not only of red cells in the circulation, but also of some at least in the marrow, even of normoblasts, as suggested by the large number of naked nuclei found later in the circulation. The marrow responds in this emergency with nucleated red cells of normoblastic or megaloblastic type, depending upon the extent of the destruction. Applying these conditions to pernicious anemia, it seems possible that an analogous toxine may be present, destroying red cells both in the circulation and in the marrow, so that in the reaction nucleated red cells are used to supply the deficiency; that further action of the toxine reduces the erythrogenetic groups more or less to the megaloblastic centers, diminishing greatly the regenerating power of the marrow, and resulting in a discharge of megaloblastic cells in the hasty effort to supply the needs of the circulation." On this theory it is easy to explain why the presence of a large number of megaloblasts in the circulation is of graver prognosis than the presence of few megaloblasts and many normoblasts. Everyone interested in the subject of pernicious anemia should read this extremely valuable contribution of Bunting's.

In connection with this subject several interesting cases have been described recently. Thus, Thompson (Medical News, April 8, 1905) describes a most interesting case of anemia due to infection with the Dibothriocephalus latus. In this case the reds were 608,000 per c. mm. and the hemoglobin 20 per cent. The high color index, the large number of macrocytes, the presence of normoblasts and megaloblasts and the leucopenia, with absence of the eosinophiles, made Thompson regard this case as one of pernicious anemia. Under treatment, which consisted of the usual dietetic and hygienic measures, with the administration of oleoresin aspidii, arsenic by mouth and hypodermically, Basham's mixture, and adrenalin chloride, a complete cure resulted, the reds reaching 5,980,000 and the hemoglobin 98 per cent. Two other cases of the same kind and due to the same cause are reported by Meyer in the same number of the journal.

REVIEW IN PATHOLOGY.

Under the Supervision of José L. Hirsh, M.D., Baltimore. THE BIOLOGY OF THE MICRO-ORGANISM OF ACTINOMYCOSIS. James H. Wright. Publications of the Massachusetts General Hospital, Vol. I, No. 50.

To this essay was awarded the Samuel L. Gross Prize of the Philadelphia Academy of Surgery. The study is a rather exhaustive one, covering the cases of actinomycosis, with which culture experiments were made and the method of isolation employed, and a critical review of the literature of the biology of the microorganisms of actinomycosis. The conclusions are tersely summed up as follows:

Branching filamentous micro-organisms have been isolated in pure culture from 13 cases of actinomycosis in man and from two cases in cattle. These micro-organisms seem all to be of one species, for the differences among the various strains are no greater than among various strains of tubercle or diphtheria bacilli.

The micro-organisms grow well only in agar and bouillon cultures and in the incubator. In the usual culture and at room temperature it grows very little or not at all. It is essentially an anerobe. It does not form sporelike reproductive elements. In cultures its colonies are similar in character to colonies of the micro-organism in the lesions of actinomycosis. If colonies of the micro-organisms are immersed in animal fluids, such as blood serum and serous pleuritic fluid, the filaments of the colonies in immediate contact with the fluid may, under certain unknown conditions, become invested with a layer of hyaline eosin-staining material of varying thickness, and the filaments may then disappear. Thus structures are produced that seem to be identical with the characteristic "clubs" of actinomyces colonies in the lesions.

Inoculation experiments on animals were made with the cultures of the micro-organisms from 13 cases, including the two bovine cases. All of these strains were found to be capable of forming the characteristic "club"-bearing colonies in the tissues of the experimental animals. These colonies were either enclosed in small nodules of connective tissue or were contained in suppurative foci within nodular tumors made up of connective tissue in varying stages of development. With the cultures from most of the cases nodular lesions identical in histological character with those of actinomycosis were produced in inoculated animals, and with some of the cultures relatively extensive lesions considering the size of the animals. The most extensive lesions showed little progressive tendency, and only in a very few instances did multiplication of the micro-organism in the body of the inoculated animal seem probable. In view of the negative or ambiguous results of those who have inoculated healthy animals with actinomyces directly from the lesions, it would seem that the result of the inoculation with the cultures described in this paper afford as much proof as can be expected from such experiments that the microorganism in the cultures was identical with the micro-organisms in the original lesions.

From his own observation and from a study of the literature Wright is of the opinion that but one species of the micro-organism is the characteristic infectious agent in typical actinomycosis, and that is one with the properties described in this paper. This micro-organism should retain the generic and specific name of Actinomycosis bovis.

The differences between actinomycosis from the human and bovine cases were not sufficient to justify their classification as separate species.

Wright does not accept the prevalent belief that the specific infectious agent of actinomycosis is to be found among certain branched micro-organisms, widely disseminated in the outer world, which differ profoundly from Actinomycosis bovis in having sporelike reproductive elements. He thinks that these should be grouped together as a separate class, with the name nocardia, and that those cases of undoubted infection by them should be called nocardiosis, and not actinomycosis. The term actinomycosis should be used only for those inflammatory processes the lesions. of which contain the characteristic granules or "drusen." That a nocardia ever produces these characteristic lesions has not been convincingly shown. Because the micro-organism here described does not grow well on all the ordinary culture media, and practically not at all at room temperature, Wright does not conclude that it has its usual habitat outside of the body. He thinks that it is a normal inhabitant of the secretions of the buccal cavity and of the gastrointestinal tract, both of man and animals. In these secretions it will probably be found in the form of fragmented filaments, growing in company with bacteria, and not differentiated from them. He believes that the part played by foreign bodies so fre

quently found in actinomycotic lesions is not that of the carrier of the actinomycotic organism into the tissue from without, but that the foreign body, by its traumatic and irritative effects, furnishes a nidus in the tissues for actinomyces which enters therein with the secretions from the buccal cavity and gastrointestinal tract, develops into characteristic colonies, and produces lesions which we call actinomycosis. Concerning the clubs of the actinomyces colony, it is undetermined whether they are an essential product of the micro-organism itself, that is, a kind of product analogous to capsule formation among bacteria, or a deposit upon the microorganism from the surrounding tissue and fluids. The author thinks that animal fluids are essential to their production. The chief function of the clubs is to protect the mass of the colony from the destructive action of the juices and cells of the tissue. Where the resistance of the tissues to the infection is apparently very slight, little or no club formation may occur, and the colonies may consist only of masses of naked filaments.

Concerning the importance of the bacteria which are so frequently found accompanying the specific micro-organism in the lesions, it is probable that they play an important part in the extension of the disease, although the Actinomycosis bovis is capable of acting as the sole infectious agent.

The so-called spores, cocci, and bacilli described by various writers in the granules of actinomyces directly from the lesions are either products of degeneration and disintegration of the filaments of the specific agent or are real micrococci and bacilli growing in symbosis with it.

In consideration of the fact that Actinomycosis bovis has never been shown to have a high degree of virulence for experimental animals, the progressive character of some of the spontaneous cases may be explained by the important factor of individual susceptibility or lack of resistance to the infection. The factors of secondary bacterial infection and of continuous reinfection by way of sinuses connecting with the buccal cavity and with the gastrointestinal canal may be of great importance. That such sinuses are common in actinomycosis is well known, and that repeated reinfections with this specific micro-organism, as well as others, could thus easily occur is obvious if the assumption be true that Actinomycosis bovis is a regular inhabitant of the buccal cavity and of the gastrointestinal tract.

ETIOLOGY AND CLASSIFICATION OF SUMMER DIARRHEAS OF INFANCY. C. H. Dunn. Archives of Pediatrics, June, 1905. Dunn gives a review of the work which has been done on the bacillus dysenteriae, and presents the results of his own observations on the study of 620 consecutive cases of summer diarrheas. The conclusions of the paper are:

1. The diarrheal diseases of infancy occurring in the summer months differ in no way, either clinically or anatomically, from the

diarrheal diseases occurring in the cooler months, except in their much greater frequency.

Classification on an anatomical basis, as, for example, into functional or organic, or non-inflammatory and ileocolitis, is not convenient for etiological study owing to the variety of lesions found in cases of similar etiology and similar clinical course, and to the lack of correspondence between anatomical and clinical pictures.

3. The following classification is suggested: (a) Acute nervous diarrhea, characterized by loose stools of normal color and odor, without abnormal constituents. (b) Irritative diarrhea. Acute intestinal indigestion of the irritative type, characterized by the absence of persistent fever and by the presence of curds and undigested masses in the discharges. (c) Fermental diarrhea. Acute intestinal indigestion of the fermental type, characterized by the absence of fever and by green stools of a foul or sour odor. (d) Infectious diarrhea, characterized by the existence and persistence of fever and by the tendency of early signs of ileocolitis, as shown by the presence of blood and excess of mucus in the discharges. When a specific organism, the bacillus dysenteriae, is proved to be the cause the case may be further particularized by the term infantile dysentery. (e) Rare cases occur, corresponding to the known description of heat exhaustion and cholera infantum. 4. Of the above differentiated types, the indigestion, including the irritative and fermental cases, is by far the most common.

5. The chief or primary cause of all the above types is the increased heat of the weather during the summer months, which probably acts in the non-infectious cases by producing functional disturbances either of the nervous system or of the digestion, and which acts in the infectious cases by producing in the intestine conditions more favorable to the occurrence of infection. The name thermic diarrhea can be given to the entire group.

6. Bacteria are the secondary cause of a certain number of cases, such cases being mainly, if not wholly, of the type classified as infectious.

7. Infection occurs by the introduction of bacteria from without or by autoinfection with bacteria already in the intestine. The latter is probably the usual method.

8. The bacillus dysenteriae is the cause of most of the infectious cases. Whether it is the sole cause remains to be determined. 9. The bacillus dysenteriae can often be found in the intestines. in cases where it probably has no causal relation with the pathologic processes. Such cases are usually clinically of the non-infectious type.

IO.

cases.

II.

Other organisms are probably the cause of some infectious

The anatomical changes of various kinds included under