The archiblastic group corresponds to those generally ascribed to epi and hypo-blast; the parablastic to that derived from mesoblast. Mr. Williams has evidently no belief in the presence of micro-organisms as the cause of malignant tumours, for at page 140 he remarks, “Malignancy then depends upon the indefinitely sustained activity of lowly organised cells, which grow and multiply independently, without ever reaching a high grade of organisation. To such causes I attribute the distinctions between malignant and non-malignant neoplasms, and not to any essential difference in the nature of the morbid process. Viewing the matter in this light, I can see no probability of there being any truth in the theory that malignant neoplasms are the outcome of general blood disease, due to the pressure of micro-organisms, like tubercle and syphilis : cancer cannot be inoculated, and it is not contagious. Its infectiveness is due to the autonomous power of its constituent cells, which everywhere tend to reproduce the parental type; whereas the lesions of phthisis and syphilis are inflammatory products, caused by the intrusion of foreign germs ab-extra. The agency of microorganisms is no more necessary to account for the phenomena of cancer and tumour formation than it is to account for the development of a tooth or a hair." We think, however, that it is doubtful whether it is justifiable to say that "Cancer cannot be inoculated, and it is not contagious." The difficulty of experimental inoculation, under suitable conditions, is so great that a complete investigation has never been possible, and there certainly is some clinical evidence that cancer is contagious.

The remarks on ætiology call for little notice, but it may be observed that they are to a great extent corollaries of what has gone before. One statement on page 192 can however hardly go unchallenged, where the author states that "in animal tissues we have no certain evidence that external stimuli can ever excite their cells to proliferation; they appear to cause only inflammation."

In conclusion, we think that Mr. Williams has done well to embody his arguments in their present form, and we look forward with interest to his future communications.

A DIRECTORY FOR THE DISSECTION OF THE

HUMAN BODY.*

CLELAND'S Directory has been so long and favourably known that there is little left to be said about it on the appearance of a new edition. Every school has its own traditions concerning the best method for displaying the structures in certain parts of the body, and those in the book under review in some cases are different from the plans in vogue elsewhere, but it may safely be said that the student who pursues Professor Cleland's directions carefully will not find that he has missed much by the time that he arrives at the end of his anatomical studies.

THE SECTIONAL ANATOMY OF CONGENITAL CECAL HERNIA.†

THIS brochure contains an account of a series of sections through the pelvis and inguinal regions of a subject with a large congenital hernia, and consists of thirty pages of letter-press and three coloured plates. The subject was a powerful man who was brought into the Anatomical department of Trinity College, Dublin, and the sections were cut at different levels after the body had been frozen. The hernia contained portions of the cœcum, and vermiform appendix, ileum and mesentery. There was found a curious pouch of peritoneum lying on the outer side of the hernia and quite independent of it. This the authors regard as a fœtal structure originated by the gubernaculum muscle. A close examination of the sections reveals many points of interest both to the surgeon and the anatomist. The plates are reduced facsimiles of the originals and are beautifully executed.

* A Directory for the Dissection of the Human Body. By John Cleland, M.D., LL.D., F.R.S. Third Edition, thoroughly revised by J. Y. Mackay, M.D. London: Smith, Elder & Co. 1888.

†The Sectional Anatomy of Congenital Cocal Hernia. By E. H. Bennett, M.D. and D. J. Cunningham, M.D. Illustrated. H. K. Lewis. 1888.

London :

RETROSPECT.

223

OPHTHALMOLOGY.

BY E. WOOD-WHITE, B.A., M.B.

A Case of Injury to the Eye from Lightning Stroke. Dr. Buller, Arch. Ophth., Vol. xvii.-The stroke caused complete loss of consciousness and collapse, so intense that for some time life seemed extinct, three quarters of an hour elapsing before there was any sign of recovery. Examination showed that the electric fluid struck the head above the left eye, singeing the lashes and leaving a red mark on the brow, it then passed in front of the ear, down the side of the neck, the median line of thorax, and finally traversed the outer surface of each lower extremity. Complete paralysis of the pharynx, tongue, and of the muscles of the body and extremities followed. There was also a suffusion of the lids of the left eye, causing complete closure, and there was a slight effusion in the anterior chamber. The paralysis and effusion gradually passed off; but for several weeks the left eye was drawn inwards and upwards. The patient was examined sometime afterwards by Dr. Buller, who then found nothing abnormal in the external appearance of the eyes. An ophthalmoscopic examination, however, revealed an opacity of the posterior part of the left lens, circular in outline, but not defined, and some opacities in the vitreous. The optic nerve was pale, its margins blurred and indistinct, and the arteries and veins were much diminished in calibre, some of them having white borders. At the periphery there was a large patch of pigment, in the centre of which there was a patch of orange colour. V. The author considers that the lesions to the nerve may have been caused by an effusion into the tissues of the orbit, causing pressure on the optic nerve, an effusion into the sheath of the nerve, or an interstitial neuritis

resulting from concussion. The peripheral pigmentation may have been due to a rupture of the choroid and hæmorrhage. He states that all these lesions are such as might have resulted from an ordinary traumatism, and he considers it probable that the lesions were caused by mechanical violence rather than by the chemical or thermal action of the electric fluid.

Dr. Bull has

The point

A Contribution to the Treatment of Membranous Opacities of the Vitreous.-Dr. Bull, Boston Medical and Surgical Journal, July, 1888. The author states that opacities of the vitreous in the form of membranes or shreds are rarely freely moveable, and resist internal treatment. Operation by incision with a needle was first recommended by Von Græfe. performed the operation in seventeen cases selected by preference for the introduction of the needle was just in front of the equator of the eye, and below the insertion of the external rectus muscle. There is no danger of loss of vitreous or hemorrhage, but the puncture must be well behind the ciliary processes, and pressure with the forceps must be avoided. As a rule little or no reaction follows the operation. A protective bandage is required for a few days. Antiseptics were used in all of the cases given; in 14 there was improvement in vision; three failed to improve in sight: but there was no loss of vision from the operation in any instance. The author does not perform the operation until all inflammatory symptoms have subsided.

Retinal changes in Bright's Disease.-R. Maguire, M.D. (Lancet, July 1888). The pathology of the white patches in the retina occurring in Bright's disease is by no means clear. In the majority of cases the condition of the lesion is one of degeneration rather than that of inflammation. The white spots usually occur at some distance from the blood vessels, and they are most common in cases of granular kidney. The other feature which Dr. Maguire has found common to all cases of socalled albuminuric retinitis is high arterial tension, and he is inclined to think that the degeneration is directly due to this tension. In Bright's disease the vessels become much contracted,

consequently parts at a distance from the vessels suffer from lack of nutrition. It is well known that high arterial tension causes a diminished circulation through the smaller vessels, and consequently the retina becomes more than ever deprived of its blood supply. The rarity of albuminuric retinitis in cases of amyloid kidney, and other forms of Bright's disease where it is unusual to find cardiac hypertrophy or increased arterial tension lends support to the theory advanced. The author has found

vision improve in many of his cases where high tension has been combated by rest in bed, and the use of calomel and salines. Insufficiency of Internal Recti Muscles.-H. Hansell, M.D., Medical News, August, 1888. The strain and headache caused by uncorrected errors of refraction are widely known both by the profession and laity; but it is perhaps less recognised that insufficiency of the extrinsic muscles of the eyeball frequently give rise to somewhat similar symptoms. When it is of high degree the patient complains of occasional double vision, and the degree of deflection can be easily ascertained; but when the insufficiency is slight, no strabismus can be detected and diplopia is absent. In such cases the tests must be modified by the induction of vertical diplopia by means of a prism, which must be used strong enough to overcome the superior or inferior rectus, the base being placed directly upwards or downwards. A lighted candle placed at a distance of 20 feet will then appear double. Now if the external and internal recti muscles are in equilibrium, one light will appear directly over the other; but if the internal muscles are too weak and the lines of vision diverge, the patient will have a crossed diplopia as well. The prism placed horizontally, which is necessary to bring the light back to the vertical line, will be the measure of the defect. The symptoms in these cases are very similar to those caused by refractive errors, Close work is only possible for a short time. Neuralgia, nausea, dizziness are often complained of. The causes of insufficiency may be divided into those of constitutional and local origin. Among the former are mentioned malaria, exhaustion from overwork or

P