bumens are converted into non-coagulable proteid, and certain by-products, among them leucin and tyrosin, make their appearance.

Differences are noticeable in the readiness with which autolysis of organs takes place under different pathological conditions. Jacoby found that liver autolysis was much accelerated in animals poisoned with phosphorus; and I have made some tentative experiments upon the rapidity with which organs from infected and noninfected human beings undergo this change.

Many of you will have been impressed with the remarkable softness presented by the liver, spleen, kidneys and other organs in persons who have succumbed to typhoid fever, peritonitis, septicæmia, etc. This softness has nothing to do with putrefaction, and I think it reasonably certain that it is the result of autolytic processes which may have begun to operate even before death. The changes through which the acutely swollen spleen, such as is met with in typhoid fever, goes illustrate very well the manner of action of these ferments. The diffluent quality of the spleen in this disease quickly develops outside the body; and it can be shown to be independent of the post-mortem growth either of the typhoid bacilli or putrefactive bacilli. Every pathologist has seen a moderately firm spleen outside the body become soft and semifluid in a few hours; and I find that, reduced to pulp and placed under toluol-water, the same change takes place.

In view of the resemblance of the hepatic lesions of advanced phosphorous poisoning to those of the liver in acute yellow atrophy, and the frequency with which the latter obscure disease supervenes upon acute infections, and, further, in view of the close agreement of the chemical products of degeneration of liver tissue in yellow atrophy with those of autolysis of the liver,

the question arises whether the hepatic lesions in acute atrophy may not be the result of active autolytic processes set up by some agent that is as yet unknown.

The alterations in structure and consistence of muscle occurring in certain acute diseases (such as the so-called Zenker's degeneration which appears in typhoid fever) have features in common with changes noted in autolysis. The softening and preparation for absorption of infarcted areas in the brain, kidneys, spleen and other organs are also attributable to the action of intracellular ferments; and a similar form of softening occurs, if imperfectly, in malignant tumors, notably carcinoma, and in syphilis, where ferment action is possibly accelerated through the use of drugs, of which potassium iodide is the most efficient in use.

It

On the other hand, not all dead tissues are subject to this digestive liquefaction and absorption. Tuberculous foci, though degenerated, are remarkably persistent; and, as Prudden has shown, undergo softening probably only when certain bacteria invade secondarily the necrotic areas. is of importance, in this connection, to recall that streptococci, which in themselves are not energetic tissue dissolvers, bring about softening and cavity formation in tuberculous foci; and the question as to whether their action is a direct one through products of their growth, or an indirect one by causing an increase in autolytic ferments, is pertinent but not as yet to be answered.

Fresh pus obtained, let us say, from an empyema, or fresh sputum, kept under toluol at the body temperature, becomes fluid, and a creamy layer collects upon the surface. The cells and nuclei disappear, and there appears in the fluid, as Naunyn first ascertained in 1865, various distintegration products, among which are leu

Pus

ein, tyrosin, xanthin, guanidin, etc. which thus undergoes digestion is capable of dissolving fibrin and even portions of organs independent of the action of bacteria. From this the conclusion can be drawn that pus, or really the leucocytes of pus, possess active digestive properties, a fact which the history of abscess formation and the removal by leucocytes of necrotic and other kinds of tissue, renders easily comprehensible. Many years ago Weigert attempted to explain, by assuming the operation of a peculiar poison which prevented fibrin-formation, the absence of fibrin from abscesses, etc., in which the fibrin factors must have originally been present. It is much more probable that what happens is a digestive transformation of fibrinogen, or of fibrin at the moment of its formation, by the ferments of the pus cell.

Broadly speaking, exudates and necrotic tissue are removed in two ways: (1) by absorption, and (2) by organization. In the first mode disintegration and solution of the cells, etc., with the exception of the fat and certain other elements, such as pigment, take place, and an emulsion results well adapted for entrance into the lymphatics. In the second, new vessels develop and invade the exudate or necrotic tissue, and by supplying a fresh set of leucocytes to dispose of the offending material, it is finally removed. From what has already been said, the first series of changes will readily be recognized as caused by autolysis; but the operation of the same cause is not so apparent in the second series. And yet, the two series are essentially the same. In the one the original material. contains ferments of a kind and a quantity. sufficient to bring about the transformation which is necessary before absorption can take place; in the second, the ferments being originally insufficient, are renewed

by fresh leucocytes which emigrate from the vessels, load themselves with débris, and finally accomplish their entire removal.

There is little doubt that in many pathological conditions the leucocyte is the essential agent in bringing about absorption; and what is required to accomplish this end is not living leucocytes so much as large numbers of these cells, since autolysis proceeds independently of the vitality, as such, of the cells. The fate of pathological formations is dependent in large part on the numbers of leucocytes present within them.

The different behavior of a caseous and croupous pneumonia; the facility with which the one and the difficulty with which the other undergoes resolution is to be ascribed probably in part to the absence in large measure of leucocytes from the tuberculous process and their presence in enormous numbers in the. acute inflammatory condition. Other examples illustrating the importance of leucocytes in promoting autolysis and absorption might be given.

I have been interested for the past two years in studying autolysis of the exudate in the lung in two inflammatory conditions, namely, acute lobar pneumonia and unresolved pneumonia. The pathology of the latter condition, except so far as the organization of the exudate is concerned, is, as you know, involved in the deepest obscurity. The study of the histology of the lung in various stages of the process of organization emphasizes one pathological condition, the import of which appears great in view of our present knowledge of autolysis; the exudate in unresolved pneumonia is fibrinous rather than cellular, and many of the alveoli of the lung are filled with dense hyaline fibrinous masses. All attempts to explain upon ordinary etiological grounds the peculiar changes, or absence of changes, in unresolved pneumonia, have failed; and

evidently the peculiarity of the process is to be sought in other causes.

Friedrich Müller first studied autolysis. of the lung in croupous pneumonia, and described in detail its occurrence and the chemical products, among which are lysin, leucin, tyrosin, purin bases and phosphoric acid, of the digestive process. I have found that it is in the stage of gray hepatization that autolysis takes place quickly and perfectly, while in the stage of red hepatization it is very imperfect—a fact that can, I think, be attributed to the small number of pus cells present in the latter condition. But if the lung in unresolved pneumonia is exposed to conditions favoring autolysis, the process is slow and incomplete as compared with what takes place in gray hepatization. In gray hepatization, autolysis after death is a mark of the tendency during life of the exudate to become absorbed; in unresolved pneumonia the absence or reduction of autolysis is equally an indication of the future fate of the exudate, namely, during life to undergo organization.

I am, therefore, inclined to view unresolved pneumonia as an acute lobar pneumonia in which the inflammatory exudate, either because of some disproportion between the leucocytes and other constituents, or other cause as yet unknown, failing to autolyze perfectly, can not be absorbed, and hence undergoes organization.

SIMON FLEXNER.

UNIVERSITY OF PENNSYLVANIA.

SCIENTIFIC BOOKS.

A Revision of the Lepidopterous Family Sphingida. By the Hon. WALTER ROTHSCHILD, Ph.D., and KARL JORDAN, M.A.L., Ph.D. Novitates Zoologica, Vol. IX., Supplement. Issued at the Zoological Museum, Tring, April, 1903. Pp. cxxxv+972; plates I-LXVII. 4to.

This great work, based upon the splendid collections contained in the museum at Tring,

and also upon all the other large collections in Europe as well as those in America, which have been carefully consulted, has occupied the learned authors fully eight years in its preparation. It is truly opus magnificum. On every page it gives evidence of the most painstaking and minute research, and is the first really satisfactory attempt to collate and bring into systematic review what has been done during the past one hundred and fifty years in relation to the large and interesting family of insects with which it deals.

The work falls into three parts: The Introduction, covering one hundred and thirty-five pages; the descriptive portion, occupying eight hundred and thirteen pages; and a Synonymic Catalogue of the Sphingidæ of the World, to which one hundred and sixty-seven pages are allotted. Sixteen of the plates are devoted to figuring hitherto little-known or hitherto undescribed species. These plates are executed in photo-colortype, or by the half-tone process. The remaining fifty-one plates, which are beautifully engraved upon stone, are devoted to the illustration of anatomical details. Evidently neither labor nor expense has been spared in making the treatise one of the most satisfactory pieces of monographic work which have ever issued from the press.

The introduction has value not merely for the lepidopterist, but for all students of the biologic sciences, inasmuch as the laws and methods of procedure, which should govern in systematic work, are taken up and discussed at length. The statements which are made as to the principles of nomenclature are especially worthy of study, and the conclusions reached are such as undoubtedly command the respect and win the adherence of all those who are sufficiently well versed in this subject to appreciate the position taken by the authors.

The hawkmoths are divided into two great groups, the Sphingidæ Asemanophora, including the subfamilies Acherontiina and Ambulicine; and the Sphingidae Semanophoræ, including the subfamilies Sesiinæ, Philampelinæ, and Chorocampinæ. The law of priority' has been strictly applied in ascertaining the generic names, which should be used.

The result may appear, to the student who is familiar with current nomenclature, in some cases strange, if not even startling, but the evidence submitted for the entire correctness of adopting the changes from current usage is, in the judgment of the present writer, cogent, and in almost every case entirely convincing. So far as the nomenclatorial adjustments touch familiar North American species, it may be worth while to point them

out.

=

The species named cingulata by Drury is referred with its congeners to the genus Herse Oken. The genus Protoparce Burmeister receives into its embrace our species sexta: carolina Linnæus, quinquemaculatus = celeus Hübner, occulta, rustica and brontes. For the species named hageni Grote the genus Isogramma is erected; for cupressi Boisduval the genus Isoparce is proposed and described; and for elsa Strecker the genus Dictyosoma is set up. For Sphinx plebeja Fabricius the authors propose and describe the new genus Atreus. Inasmuch as Atreus is preoccupied in the Arachnida by Koch, the present writer proposes to substitute for it the generic name Atreides and this name will be given to the genus in The Moth Book,' which is now

going through the press. To the genus Hyloicus are referred the species hitherto generally assigned to the genus Sphinx in American lists. Our species modesta Harris, which has recently quite erroneously been referred to the genus Marumba Moore, is put into the genus Pachysphinx, which is erected for its reception. Inasmuch as the type of the genus Sphinx Linnæus is undoubtedly ocellata Linnæus (see Systema Naturæ,' Ed. X., p. 489), the American congeners of this species are placed in that genus, and the name Smerinthus Latreille, hitherto almost universally applied to them, is dropped as a synonym. As the type of the genus Sesia, erected by Fabricius, is undoubtedly the species named tantalus by Linnæus, this generic name is retained for that species and its congeners. This will no doubt provoke protest from recent authors, but the step is logical, consistent, and in fact the only one which can

be taken unless the 'law of priority' is to be set aside and disregarded. The generic name Hæmorrhagia is applied to thysbe Fabricius and its allies, while the genus Macroglossum Scopoli, of which the European stellatarum is the type, is placed in the Philampelinæ, at a wide remove from Hæmorrhagia (Hemaris auctorum), with which it has hitherto commonly been associated. Our common Morning Sphinx falls under the arrangement adopted into the genus Celerio and appears as Celerio lineata.

The work deserves the most careful study, and will remain a monument to the learning and the liberality of the distinguished nobleman and his erudite colleague, who have prepared it. W. J. HOLLAND.

CARNEGIE MUSEUM, June 12, 1903.

Variation in Animals and Plants. By H. M. VERNON, M.A., M.D., Fellow of Magdalen College, Oxford. New York, Henry Holt & Co. 1903. Pp. 415.

Since Darwin's Variation of Animals and Plants under Domestication' we have had no general résumé of the principles of variation. Yet this period has witnessed the rise (and fall) of many speculations on the subject, and for the past decade has yielded the solid fruits of biometric and experimental investigation.

This important gap is now filled by the well-arranged collection of data to be found in Vernon's book. These data are considered under three main headings as follows: 'The Facts of Variation'; 'The Causes of Variation'; and 'Variation in its Relation to Evolution.' In the first part some of the results of biometry are given without going into the more abstruse mathematical methods. In connection with the discussion of discontinuous variation De Vries's theory is considered in some detail. The causes of variation are classified as blastogenic and environmental, and several chapters are devoted to the latter class. In the third part the author discusses the action of natural selection on variations, and gives some of the evidence for the inheritance of acquired characters, based on the cumulative effects of the conditions of life

(where we miss the results of Standfuss and Fischer), and finally discusses adaptive variation. The author admits the importance of self-adaptations, which are, however, in his opinion, of little effect without natural selection. Degeneration' is a difficulty that the author does not attempt to compass, while admitting the unsatisfactory nature of Weismann's explanation. He should remember that the theory that phylogenetic degeneration' is due to disuse has inadequate support, and that animals with degenerate' organs, however produced, can still be adapted if they get into situations where such organs are of

no use.

6

The book will be a welcome one to those who desire quickly to get at the recent literature on variation. The data are given in an impartial, sometimes even colorless way. The book lacks the vigor of the special plea and the enthusiasm of the book of one idea. It will be found very useful; but it will not found a school. C. B. DAVENPORT.

SOCIETIES AND ACADEMIES.

NEW YORK ACADEMY OF SCIENCES.
SECTION OF GEOLOGY AND MINERALOGY.

A REGULAR meeting of the Section of Geology and Mineralogy was held at the rooms of the American Museum of Natural History on the evening of April 20, with Professor Kemp in the chair. Dr. A. A. Julien presented the results of his work on the hornblende schist which occurs at the extreme northern end of Manhattan Island near Spuyten Duyvil Creek. He was able, in the first place, to prove the undoubted igneous origin of this rock by the unaltered crystals pointing to an original gabbro which it still preserves. The speaker then presented his views in favor of the igneous origin of all the hornblende schists of Manhattan Island.

The second paper was by Mr. D. W. Johnson, on 'The Geology of the Cerrillos Hills, New Mexico.' The Cerrillos Hills form the most northerly group of a series of four laccolithic mountain masses in north-central New Mexico. The relation of these hills to the associated Cretaceous beds and the age of the intrusion

were discussed. A brief petrographical description of the several igneous rocks was given and the subdivision and correlation of the sedimentaries on paleontological grounds considered. The origin of the anthracite coal of the Madrid area and the origin of the famous turquoise deposits of the hills were then treated. The speaker closed with a résumé of the geologic history of the region. Professor Kemp led in the discussion which followed. Dr. H. S. Washington was asked by the chairman to calculate an analysis of the type of andesite which is found in the Cerrillos Hills. GEORGE I. FINLAY, Secretary pro tem.

ON May 18 the first paper was by Dr. George I. Finlay, of Columbia University, and was upon 'The Geology of the Nephelite Syenite Area at San José, Tamaulipas, Mexico.'

In this paper Dr. Finlay said in part: The town of San José in the state of Tamaulipas, Mexico, lies in a hollow surrounded on all sides by mountains, and is about seventy miles from the coast of the Gulf of Mexico. The range of peaks immediately to the south of it, and extending for fifteen miles in that direction, is of nephelite syenite. The range is known as the San Carlos Mountains. San José itself is on the site of an eroded laccolith of andesite (locally known as 'porphyry '), intruded into limestone. Some limestone masses stand on end within the areas of the laccolith, and are thought to have floated or worked their way down to their present position during the intrusion of the igneous rock. There are two or three hundred of these isolated limestone masses, and it is in connection with these that the copper ores are found. Contact metamorphism has not been developed to any great extent in the limestone surrounding the laccolith, but has been greatly induced in the included masses, marble, grossularite, vesuvianite and several other minerals being the products. Aside from the occurrence of the nephelitesyenite in the area south of the laccolith, the region is interesting on account of the dyke rocks which are found cutting the andesite of the laccolith. Among these are analcite