Page:Popular Science Monthly Volume 43.djvu/136

126 The chapter on animal parasites contains a reference to the Amœba coli and its relation to dysentery, and also brief reference to the presence of coccidia in certain epithelial growths. The chapter on vegetable parasites contains reference to ptomaines, toxins, and toxalbumins, as well as an excellent summary of the important question of immunity, though the authors do not commit themselves to any doctrine regarding that subject.

The subject of infectious diseases induced by the pyogenic bacteria has been rearranged and placed as one of the earlier chapters in the work, which seems to us to be an excellent plan. An illustration of the caution displayed by the authors is shown in the section on lupus, in which reference is made to the fact that, while that disease is a form of tubercular inflammation, it is not unlikely that in the clinical group of diseases called lupus there may be lesions that are not caused by the tubercle bacillus, a point that must be decided by more exact bacterial studies. This same caution is shown in accepting the bacillus described by Lustgarten as the cause of syphilitic inflammation.

The skepticism expressed in the former edition regarding the causative relationship of Löffler's Bacillus diphtheriæ to diphtheria, has been supplanted by a frank acceptance of that organism, the first sentence in the section on diphtheria defining that as an acute infectious disease caused by the Bacillus diphtheriæ.

New sections on rhinoscleroma, tetanus, influenza, smallpox, scarlatina, measles, and actinomycosis, and descriptions of the Bacillus ædematis maligni, Bacillus pneumoniæ, and BaciUus coli communis have been added.

The chapter on tumors contains a reference to the structures that have been found in and between the cells of tumors, "inclusions" that the authors consider to be invaginated epithelial or other cells, or cell nuclei that have undergone various degenerative metamorphoses, fragmentation, etc. They state that some of the cell inclusions in carcinoma may be coccidia or allied organisms; but while not asserting that tumors can not be caused by parasites, they do not believe that adequate ground exists for believing that they are so caused, because the transplantation of tumors from one species of animal to another has almost uniformly failed, while it has been impossible to cultivate either directly or by inoculation any constant organisms from these morbid growths. This matter is one that is attracting the attention of pathologists in several countries, and the more thorough study of the subject of the etiology of cancer will probably determine the status of the coccidia in relation thereto.

The section on chronic arteritis has been rewritten, the authors believing that the morbid changes in the arteries are the results of a combination of chronic productive inflammation and of degeneration occurring in connective tissue—a point of view that regards the arteries as definite parts of the body, and as likely to become the seat of chronic inflammation as the liver or kidneys.

The subject of colitis is another valuable addition, and the text is enriched by some excellent engravings of the several varieties of pathological conditions that occur in inflammation of the large intestine.

In the section on the organs of generation reference is made to the adenomata that lie on the border between the distinctly benign and the definitely malignant new epithelial tissue growths, attention being called to the fact that the more benign forms are extremely prone to develop, both in structure and malignancy, into carcinomata.

While the substitution of the terms "lymph nodes" and "lymph nodules" for "lymph glands" and "lymph follicles" respectively was recommended in the last edition, the change has been made throughout the text in this volume.

The work is fully abreast of the scientific knowledge of the day, and it will undoubtedly be accorded a popularity similar to what it has received in the past.

volume is the first of a series entitled Delights of History, and a delightful book has been made of it. Beginning with the wonderful journeys of the Polos, and the expeditions sent out by Prince Henry of Portugal, events which may well have fired the imagination of the youthful Columbus, we are brought at length to the gates of Genoa. Here we learn something of the condition of the weavers among whom