spinal cord was stimulated-provided the animal was not under the influence of woorara-perhaps in consequence of the coincident irritation of vaso-motor nerve-fibres, a speedy diminution of the hæmorrhage, and in some cases even complete arrest of it occurred. This phenomenon was independent of the capability of functional activity of the nervi pudendales communes. Erection could also be called forth by excitation of the pons Varolii and of the crura cerebri at their points of entrance into the cerebrum. Eckhard draws the conclusion that the nerves inducing erection run through the pons and take their origin from some part of the cerebrum.

GENERATION.

1. WILLIAM ROBERTS, M.D., of Manchester.

Studies on Bio

genesis. (Proceed. of Roy. Soc.,' vol. xxii, p. 289.) 2. JOHN WILLIAMS. The Structure of the Mucous Membrane of the Uterus, and its Periodical Changes. (Proceed. Roy. Soc.,' 1874, vol. xxii, p. 297.)

1. Dr. Roberts's paper is divided into three sections. The first is on the sterilization by heat of organic liquids and mixtures. He finds that when beef tea or a decoction of turnip is boiled for a few minutes and afterwards preserved from extraneous contamination it passes into a state of permanent sterility. This state is characterised by loss of power to originate organisms with conservation of the power of nourishing and promoting the growth of organisms. All organic liquids and mixtures seem capable of being brought to this state by exposure to a heat of 212° F., but the length of time during which exposure to this heat is necessary to induce sterilization varies greatly according to the nature of the materials; ordinary infusions being sterilized in ten minutes, whilst milk, chopped green vegetables in water, pieces of boiled egg in water, and other mixtures, were not sterilized unless the heat was continued for twenty to forty minutes. Hay infusion was sterilized like other infusions by boiling for a few minutes, but when rendered alkaline by ammonia or liquor potassæ it was not sterilized except after an exposure to 212° F. for more than an hour; sometimes it germinated after two and once after three hours' exposure. The two factors-duration of heat and its degree-seem to be mutually compensatory, a longer exposure to a lower heat being equivalent to a shorter exposure to a higher temperature. Speaking roughly, an exposure for an hour to a heat of 212° F. appeared to be equivalent to an exposure of fifteen minutes to 228° F.).

Section 2 is devoted to the capabilities of the normal tissues and juices to generate Bacteria and Torule without extraneous infection. Egg albumen, blood serum, blister serum, milk, grape, orange, and tomato juice, turnip and potato tissue-these were rapidly removed from their ordinary sites and placed in sterilized tubes, and kept at temperatures varying from 60° to 90°, and the rarity with which Bacteria and Torulæ were developed when the last condition of the experiment were carefully preserved led to the conclusion that the

normal tissues of plants and animals were incapable of breeding Bacteria and Torulæ except under the stimulus of extraneous infection.

The third section is devoted to the bearing of these facts, which is that ordinary air and water contain, in addition to their proper elements, multitudes of particles capable of provoking germination. Dr. Roberts is therefore a panspermist, and he observes that were it hereafter established that bacteria and fungoid vegetations do under exceptional instances arise abiogenically, it would not overturn the panspermic theory, but would merely limit the universality of its application.

2. Dr. Williams's paper consists of observations made on the uteri of nine women who had died in different stages of the monthly period. Dr. Williams finds that menstruation appears essentially to consist, not in a congestion or a species of erection, but in growth and rapid decay of the mucous membrane. The menstrual discharge consists chiefly of blood and of the débris of the mucous membrane of the body of the uterus. The source of the hæmorrhage is the vessels of the body of the uterus. The mucous membrane having undergone fatty degeneration, blood becomes extravasated into its substance, then the membrane undergoes rapid disintegration and is entirely carried away with the menstrual discharge. A new mucous membrane is then developed by proliferation of the inner layer of the uterine wall, the muscular tissue producing fusiform cells, and the groups of round cells enclosed in the meshes of the muscular bundles producing the columnar epithelium of the glands.

JAMES DEWAR and JOHN E. MCKENDRICK. On the Physiological Action of Light. (Transactions of the Roy. Soc. of Edinburgh,' vol. xxvii, p. 141.)

Dr. Dewar and Dr. McKendrick consider they have experimentally proved-1. That the impact of light on the eyes of members of the following groups of animals, viz. Mammalia, Aves, Reptilia, Amphibia, Pisces, and Crustacea, produces a variation amounting to from 3 to 10 per cent. of the normal electro-motive force existing between the retinal surface and the transverse section of the nerve. 2. That this electrical alteration may be traced into the brain. 3. That those rays that we regard as most luminous produce the largest variation. 4. That the alteration of the electrical effect with varying luminous intensity seems to follow very closely ratios given by the psycho-physical law of Fechner. 5. That the electric alteration is due to the action of light on the retinal structure itself, as it is independent of the anterior portion of the eye, eliminating, therefore, the natural supposition that the contraction of the iris might produce a similar result. 6. That it is possible by experiment to discover the physical expression of what is usually called in physiological language fatigue. And, 7. That the method employed in this research may be applied to the investigation of the special organs of other senses.

109-LV.

17

Mr. J. L. TUPPER. On the Centre of Motion in the Human Eye. (Proceed. Roy. Soc.,' 1874, vol. xxii, p. 429.)

Mr. Tupper proves that the centre of motion of the eye is about of an inch, instead of 1 of an inch, behind the cornea's anterior surface.

M. ED. V. BENEDEN. The Distinct Origin of the Testis and Ovary. ('La Revue Scientifique.')

M. Beneden remarks that it has hitherto been almost universally admitted that the testis and ovary spring from the same embryonic organ, which, becoming differentiated with the advance of growth, becomes the testis in the male and the ovary in the female. His own researches, however, made on different kinds of zoophytes, and principally upon Hydractinia, Echinata, Clava squamata, and Campanularia gelatinosa, have convinced him that the axiom of the identity of the two sexual glands has no scientific basis. The testis he finds to be derived from the external lamina or ectoderm, whilst the ovary has its point de départ in the internal lamina of the embryo, which is the homologue of the endoderm of zoophytes. The homology which exists between the two primordial lamina of the embryos of Vertebrata and the two lamina which form the bodies of Zoophytes was first recognised by Huxley. At present the form "gastrula," consisting of an ellipsoidal cavity, circumscribed by two cellular lamina applied to one another, the endoderm and the ectoderm, has been observed not only amongst Zoophytes and Vertebrata, but also amongst Vermes, Echinodermata, Mollusks, and Arthropods-in a word, in all the great divisions of the animal kingdom with the exception of the Protozoa. These are generally monocellular, like the Gregarinade and Infusory Animalculæ, and never present anything comparable to the two laminæ of the metazaries. The ectoderm of Zoophytes is homologous with the external laminæ of the embryo of Vermes, Mollusks, Echinodermata, Arthropods, and Vertebrata. The endoderm has in all metazoaries the same anatomical value. For the study of the origin of the essential organs of generation M. v. Beneden selected zoophytes, in which animals the ectoderm and endoderm persist almost unaltered throughout the whole course of evolution. He finds that the ova in Hydractinia and Clava are only the modified cells of the endoderm, which the testis develops at the expense of a cellular bud which proceeds from the inner face of the ectoderm. The male organ arises from the nervous or animal layer; the female organ proceeds from the intestinal or vegetative layer, and fecundation consists in a simple mixture of ectodermic elements with a product of the endoderm. Moreover, M. v. Beneden has shown that every sporosac originally contains within itself the rudiments of an ovary and of a testis; and if this observation be associated with the researches of Waldeyer on the Vertebrata and the established fact that all animals possess an endoderm and an ectoderm, the conclusion is forced upon us that every animal is primarily hermaphrodite. In accordance, however, with the development of one or the other, the testis or ovary remains in a rudimentary condition.

REPORT ON PHYSIOLOGICAL AND PATHOLOGICAL

CHEMISTRY.

BY A. H. CHURCH, M.A.,

Professor of Chemistry at the Royal Agricultural College.

Chemistry of Food and Digestion.-The mineral or inorganic constituents of food perform two functions, or at least are found under two conditions. Those salts which are united in fairly constant proportion with the several plastic constituents, tissue materials, and combustible compounds of the body, constitute the more important section. If salts be withheld, the perfection and integrity of the organic matters is gradually destroyed, for mineral salts continue to be eliminated. When muscles are thus exhausted of their necessary complement of salts muscular exhaustion ensues, while in the nerves the excitability which first occurs is followed by paralysis of the nerve-centres. (J. Forster, in 'Zeitsch. f. Biol.,' ix, 297.)

G. Bunge (in 'Zeitsch. f. Biol.,' ix, 104) gives the results of his experiments on the functions of common salt in the animal organism. He attributes the craving for sodium chloride shown by herbivora to the excessive disproportion between the potassium and sodium salts contained in the vegetable matters on which they feed. All good analyses of cattle food show very distinctly that the quantity of potassium present is several times greater than the sodium. Now, the exhibition of potassium salts causes the elimination from the system of an increased quantity of sodium salts, probably through a decomposition of the common salt in the blood. In a single day Bunge found more than twice the normal amount of chlorine in his urine after taking during that day in three doses an amount of potassium phosphate containing 18-24 grams of KO. Still more effect was produced by taking the same quantity of K,O in the form of citrate, when an amount of common salt was eliminated (in the urine of twenty-four hours) corresponding to something like half of that calculated as present in the whole blood of the body. Bunge considers that some potassium salts decrease the excretion of phosphoric acid, though all increase that of chlorine. He further remarks that the blood-corpuscles retain potassium salts especially in the form of phosphate, and that their presence in the liquor sanguinis is injurious. Man, living on a mixed vegetable and animal diet, requires common salt from mineral sources as an addition to his food, in consequence of the quantity of potassium compounds present in the vegetables which he eats..

The nature of the transformation products of starch has been very closely studied by E. Brücke (Wien. Akad. Ber.,' (3) xv, 126). Four to five hours after a meal of boiled starch the animals to which it had been given were killed. In the stomach unaltered starch was found together with soluble starch and that variety of

dextrin (erythrodextrin) which strikes a dull-red purple tint with iodine; in the small intestine sugar was always found, but in the stomach itself mere traces of it, showing that the ptyalic ferment had done but little work, and that its action had been arrested by the acidity of the gastric juice. The soluble starch had been formed, probably, by the action of the acid of the gastric juice. The present reporter has found that one of the dextrins, probably achrodextrin, is the main product of the action of oil of vitriol (sp. gr. 156) upon pure cellulose when the action takes place at about 15° C. and the dissolved cellulose is, after three to six hours, thrown into cold water. Brücke regards erythrodextrin as a product of the action of lactic acid upon starch-the lactic acid itself being producible by the action of a ferment existing in the starch upon that body. But at present, it must be owned, our knowledge of the transformation of starch, and of cellulose as well, both in the body and out of it, is by no means complete.

Those of our readers who wish to study the chemistry of starch in its most recent developments should read a little brochure of 116 pages just published at Leipzig. It is a memoir by Dr. Walter Nägeli, and gives an account of the different varieties of starch, and of dextrin as produced from starch. A complete bibliography of starch renders this pamphlet most useful.

Dr. Resch (J. Anat. und Phys.,' 1874) concludes hydrochloric acid, secreted mainly towards the cardiac extremity of the stomach, to be the free acid mainly concerned in the digestion of albuminoids. It is concluded by Von Wittich ('Pflüger's Archiv,' vii, 18) that the fundus portion, and not the pyloric, of the mucous membrane of the stomach has the power of digesting albuminoids-that is, of converting them into peptones. G. Wolffhügel (loc. cit., 188) agrees with V. Wittich and others in denyingto the pyloric glands the power of secreting pepsin, but later on the view of V. Wittich seems modified (loc. cit., viii, 444).

The chemical and physical distinctions of different albuminoids or proteids have been discussed by A. Béchamp (Compt. Rendus,' Îxxvii, 1525). His acquaintance with previous researches is obviously very limited. Both Béchamp and Dumas seem to think that they discovered for the first time in 1873-4 the existence of three albuminoids in cow's milk; the present reporter gave methods for separating and estimating them in 1870, in his Laboratory Guide,' 2nd ed., p. 169.

The seat of the change and breaking up of albuminoid matters in the body has been discussed by Hoppe-Seyler (Pflüger's Archiv,' vii, 399, 1873). He concludes that this metamorphosis cannot occur in the blood nor in the lymph bathing the tissues, but in the substance of muscles and glands. Thus it is the living cells of the tissues themselves, the albuminoid constituents of which suffer continual change and oxidation by the agency of the oxygen diffused to them through the capillaries.

The changes induced by ferments of various orders, such as ptyalin, pepsin, diastase, &c., are lessened or arrested by carbolic acid and by