From familiar things I pass to things little known; that is, to the early stages of the lizard.

In the early stages I cannot confine myself to the nerve-supporting organs, but, of set purpose, let my work overlap that of my friend Mr. Balfour, who is, to me, the typical embryologist; Mr. Milnes Marshall's excellent papers, however, are not forgotten.

Much that is figured of the earlier stages is not described; my illustrations can, however, easily be compared with those of the chick in Foster and Balfour's work; and with the copious and exquisite illustrations given in Mr. Balfour's work on the "Elasmobranchs."

The reader is asked to refer to these works, especially the latter; that he may see how perfectly my observations on the embryo of the lizard correspond with what Mr. Balfour has discovered in other types.

Some of the most important of them relate to structures that must be well understood before we can gain even the most elementary conceptions of the morphology of the vertebrate skeleton.

These are the brain and main nerves; the sense-capsules; the respiratory openings (clefts) through the wall of the throat; the "pituitary body," and its relation to the mouth and brain; and the extension into and subdivision of of the pleuro-peritoneal cavity in the head, even in front of the mouth.

The modification of the "segmental" muscular masses in the head; the difference between the axial structures of the head and the body; all these things have to be carefully attended to.

I will now propound my own theory of the skeleton of the head and throat, as compared with the skeleton of the body generally, namely, the spine and thoracico-abdominal cavity.

The undivided condition of the paired tracts, on each side of the notochord, which is so constant in the head, is the original state of things; the head is archaic, the trunk, with its vertebræ intercalating with the muscle-plates, is a much more modern result of evolutional metamorphosis than the undivided head; the limb-girdles and limbs are the newest of all.

Archaic entomocranial Vertebrates, had no vertebræ, properly speaking; they had a long head, composed of fourteen or fifteen segments; their throat was a large multiperforate bag; and instead of having one vagus nerve, they had seven or eight pairs of vagi, forking over all the respiratory passages, except those supplied by the glossopharyngeal and portio dura.

Some of them were like Cæcilians; they had long, vermiform bodies, and scarcely any tail behind their anal opening; they had no finished vertebræ, but a semi-solid, half-cartilaginous tube, surrounding the notochord.

Others were a sort of exaggerated tadpoles; they were the fathers

of all such as gradually improved into the larval condition (for a long while permanent) of the modern Batrachia, but they were Ametabolous, or arrested.

These ancient bull-heads had a huge pharynx, under which, more than behind, a very short abdomen was swung, with a snake-coiled intestine; their body was a mere lash, like the lash on the tail of the larva of the smooth newt and Dactylethra, and the lash of the tail of the adult Chimæra.

The forms from which the Marsipobranchii on the one hand, and the Chimera on the other, sprung, were intermediate between the two extreme forms imagined; they were, however, close akin to the primordial tadpole.

What the pituitary body was, at that time, when the mesocephalic flexure just appeared; how the vesiculation of the neural axis arose; and whether the sense-capsules were at first paired or unpaired; of these things I will speak when I have obtained more light upon this dark subject.

But, even in the foggy illumination of the present, we can make out that even the term "the vertebral theory of the skull," is absurd; vertebræ, as such, are a late specialization of a segmented creature, whose mouth is opposite its nervous axis, and on the same aspect as its main circulating organ (hæmostomous).

For a long while there was no definite division into head and body; the Selachians show this to this day; their investing mass or parachordal tracts run on from the head into the body without division the occipito-atlantal articulation is very late in its appearance.

:

Moreover, both the lamprey and Heptanchus show (or indicate) that the head of modern Vertebrates has been greatly shortened— much more than their throat; the cervical vertebræ are new segments of the axis, intercalated at that part, to bind the shortening head to the retreating body.

This view is curiously strengthened by an observation of Mr. Balfour's, with regard to the formation of "somatomes" in the cervical region of the chick; the foremost do not appear first, but the 4th, 5th, 6th, &c., are to be seen first, and then the three front segments.

*

Dr. Milnes Marshall's observations on the segmental nerves of the chick, showing that the third, or motor oculi, is as good a segmental nerve as the great 5th, or trigeminal, and that the olfactory or first nerve is developed exactly in the same manner as the other cranial nerves, namely, from the dorsal region of the "epiblast; " these discoveries, I think, are of the greatest importance, and are very suggestive.

* See " Quarterly Journal of Microscopical Science," vol. xviii, New Series, Plates 2, 3, pp. 1-31.

Even those who are content to work at the development of the lowlier types, such as the worm and the cray-fish, are helping at this good work, for they are throwing light upon the evolution of the Vertebrates.

VII. "On the Chemical Composition of Aleurone Grains." By SYDNEY H. VINES, B.A., B.Sc., F.L.S., Fellow and Lecturer of Christ's College, Cambridge. Communicated by Dr. MICHAEL FOSTER, Prælector of Physiology in Trinity College, Cambridge. Received October 22, 1878.

I. The Aleurone Grains of the Blue Lupin. (Lupinus varius.) The proteids stored up in the seeds of certain plants, more especially of Leguminosa, have been stated by various observers to exist in the form of the vegetable caseins such as Legumin and Conglutin, and this view has been advocated of late years more particularly by Ritthausen ("Die Eiweiss-Körper der Getreidearten, &c., 1872 "). In 1877, Weyl published some observations ("Zeitschr. für Physiol. Chemie, Bd. I), which tend to show that the proteids exist in the seeds of these plants in the form of globulins, and that the caseins, extracted by Ritthausen and others, are the products of the alteration of the globulins effected by the reagents (alkaline solutions) used in their extraction.

In order to be in a position to form a decided opinion upon the subject, I first repeated Weyl's experiments, using the seeds of the blue lupin. I found that on treating the ground seeds with 10 per cent. NaCl solution, I obtained a fluid which gave all the reactions characteristic of fluids which hold globulins in solution. On dilution with water it gave a precipitate of a substance soluble in 10 per cent. NaCl solution (vitellin); and on saturating it with NaCl (rock-salt), a substance (myosin) was precipitated which was soluble in 10 per cent. NaCl solution.

With the view of ascertaining the value of Weyl's suggestion, that the casein (conglutin, Ritthausen) contained in the lupin was a product of the alteration of the globulin under the action of an alkaline solution, I made the following experiment: About 50 grms. of the ground lupin-seeds were placed on a filter, and 250 cub. centims. 0.1 per cent. NaHO solution poured over them. The fluid ran through in a few minutes, and was found to give the reactions characteristic of alkaline solutions of vegetable casein (see "Sachsse, Chemie und Physiologie der Farbstoffe," &c., 1877, p. 267). The residue on the filter was then well washed with distilled water until the washings ceased to give an alkaline reaction. It was then treated with 250 cub. centims. 10 per cent. NaCl solution, and on testing the filtrate it was

The residue on the filter

found to hold much globulin in solution. was then placed in a beaker with 500 cub. centims. of the 0.1 per cent. NaHO solution, and allowed to stand for twenty-four hours. At the end of that time the alkaline fluid was poured off, and the residue placed on a filter and well washed with distilled water. On treating it with 10 per cent. NaCl solution it was impossible to extract from it more than the merest traces of globulin. It appears, therefore, that the globulin had become altered by the action of the alkaline fluid, that it had in fact become dissolved in it in the form of alkali-albumin. This change probably occurs in the extraction of conglutin by Ritthausen's method.

Moreover, I found that conglutin prepared according to Ritthausen's methods gives reactions which are characteristic of the substances formed when various animal proteids are treated with dilute acid or alkaline solutions (acid-albumin, alkali-albumin), and it does not differ very widely from these substances in elementary composition. These facts support the view that conglutin is merely a product of the alteration of the true reserve-proteids. Weyl had already shown that no proteids, except such as are soluble in 10 per cent. NaCl solution, can be extracted from the seeds by treating them with 1 per cent. Na2CO3 solution. This proves that conglutin does not preexist in the seed.

I therefore agree with Weyl in concluding that the proteids stored up in the seeds of the blue lupin consist of globulins (vegetable vitellin and vegetable myosin).

Subsequent observations, however, assured me that this is not the only form in which the reserve-proteids are present. I found that the 10 per cent. NaCl extract of the seeds contained, in addition to the globulins, a proteid in solution, which was not precipitated by boiling, or by saturation with rock-salt, or by dilution with distilled water. This substance may be isolated by extracting the ground seeds with distilled water; boiling the extract several times to remove all traces of globulin ; evaporating to small bulk over a water-bath, and allowing the fluid to filter into absolute alcohol. As it drops into the alcohol a dense precipitate is formed. The substance which is thus precipitated is readily soluble in distilled water even after being exposed for months to the action of alcohol. Its solution in distilled water does not become turbid on boiling; it gives a precipitate on the addition of a drop of HNO3, which is soluble in excess of acid; it gives the xanthoproteic and Millon's reactions; it gives an immediate precipitate with acetic acid and potassic ferrocyanide; and it gives a bright pink colour when treated with excess of strong NaHO solution on the addition of a drop of dilute CuSO, solution. The substance does not dialyse. These properties and reactions indicate that the substance is allied to the peptones. It most nearly resembles the a peptone of Meisoner, or,

adopting Kühne's nomenclature ("Verhandl d. Nat.-Med. Vereins zu Heidelberg," Band I, 1876), the substance to which he gives the name of Hemialbumose; a name which may be provisionally applied to this substance also.

The proteids stored up in the seeds of the blue lupin are therefore of two kinds:

(1.) Hemialbumose-soluble in distilled water.

(2.) Globulins-insoluble in distilled water, but soluble in 10 per cent. NaCl solution.

ance.

In order to determine the exact distribution of these substances in the cells of the seed, I made a series of micro-chemical observations. Thin sections of the cotyledons were placed for a few minutes in ether and then in absolute alcohol, in order to remove the fatty matters present which would otherwise interfere with the observation. Α section examined in a drop of absolute alcohol shows the cells filled with aleurone grains lying in the meshes of a delicate matrix. They are hyaline or faintly granular, and have a yellowish tint. On adding a few drops of distilled water the grains become coarsely granular; the granules gradually disappear, and then vacuoles make their appearFurther treatment with water produces no apparent change. If now a few drops of 10 per cent. NaCl solution be added, the hyaline vacuolated grains at once disappear, and nothing remains in the cells (when the section is very delicate) but the network of the matrix. A precipitate may be produced in the fluid under the cover-slip by diluting it with distilled water. The precipitate assumes the form of rounded drops of a viscous nature which are readily redissolved on the addition of NaCl (vegetable vitellin). If the section be irrigated with 10 per cent. NaCl solution until the addition of distilled water produces no precipitate, and if it be then well washed with distilled water nothing remains within the cells but the matrix. This is rendered conspicuous by adding a drop of solution of iodine which gives it a bright yellow colour.

It is well known that aleurone grains consist essentially of proteids, but the nature of these proteids has not as yet been determined. From the foregoing observations it appears that at least one proteid is present which is soluble in water, and one which is insoluble in water but

soluble in 10 per cent. NaCl solution. The preceding chemical experiments suffice to prove that the former is hemialbumose, and that the latter includes the two forms of vegetable globulin.

My observations on the solubility of the aleurone grains of the blue lupin in water agree in the main with those of Pfeffer ("Unters. über Protein-Körner, &c. Jahrb. f. Wiss. Bot.," Band VIII, 1872, p. 447), but I have been unable to discover that, as he asserts in the case of Pæonia and Cynoglossum at least, long continued exposure to alcohol diminishes their solubility in water. Such treatment affects neither