manent cure, I shall feel contented in the idea, that my labour in the composition of this paper has not been lost or misspent. 15 SOUTHAMPTON Street, Covent Garden.

ARTICLE VI.-On Restoring the Lower Lip. By S. CHISHOLM, M.D., Inverness.

William Monro, from the parish of Urquhart, aged 60, was admitted to the Northern Infirmary in January last, having the whole of the lower lip involved in a cancerous disease. Owing to some family circumstances, he had to leave the house without having had any operation performed on him, and during his absence, applied to a medical gentleman in a neighbouring county, who excised the lip in the usual way, (V), bringing the parts together with the twisted suture. As might however be expected, from the great loss of substance, the parts, shortly after the operation, gave way. Repeated attempts to produce adhesion proved equally unsuccessful, and the man was re-admitted to the Inary about the end of March. On re-admission, the whole of the under lip, from angle to angle, and down to the chin, as represented in the plate, Fig. 1, was wanting. The saliva was constantly flowing down over the chin.

I first made an incision from the lower part of the breach in the lip, obliquely down to the side of the chin, as pointed out by the line A. Then a somewhat semilunar incision, (line B), from near the angle of the mouth to the termination of the first, and separated the flap thus formed from its connection with the gum underneath. The same was done on the other side, and the two flaps brought together with the twisted suture, as represented in Fig. 2. The parts healed kindly, and the man left the institution, extremely thankful for the result of the operation, which succeeded to my utmost satisfaction.

INVERNESS, 28th May 1842.

ARTICLE VII.-Observations on the Development of the Blood Corpuscles in the Chick, with the various changes which they present from their first appearance to their full development; with some remarks on these changes. By WILLIAM MACLEOD, Esq., Surgeon, late Assistant to Dr John Reid in the Pathological Department of the Edinburgh Royal Infirmary.

Previous to 1838, physiologists were wholly unacquainted with any general law by which the development of structure could be

explained. In that year, Schwann of Berlin induced, from the generalization of numerous isolated facts scattered through the various scientific journals, along with his own observations, the grand and universal principle, that all organized structures have their origin from cells. Since that year, numerous microscopic observers have increased to a great extent the facts by which the above principle is supported.

The following observations are designed to show the manner of formation of one of the bodies belonging to the first class of Schwann's classification of tissues-the blood corpuscles-with the different changes which they present from their first appearance to their full development. These were made on the blood corpuscles of the chick. Before describing the appearances which they present in their process of development, I shall state shortly the manner in which these observations were conducted. To get the blood perfectly pure, I removed it from the heart of the chick, (this can be done so early as the third day,) so that none of the granules contained in the nutritious matter which surrounds the embryo could enter the blood. I diluted the blood thus removed with fresh filtered serum. To allow the appearances going on within the corpuscle to be seen more distinctly, I used weak acetic acid, which was the only reagent employed. I also examined the blood contained in the germinal membrane and allantois, diluting it with the fluid albumen contained in the egg; and the appearances which the blood corpuscles presented in all these situations, were the same, provided the two last structures were examined at the proper time; for if the examination is made very early, the oval appearance of the blood corpuscles will not be seen, as they do not take this form until after the fourth day.2 By examining the blood in these different ways, I hoped to be able to remove all chance of fallacy.

1 This statement is not altogether true, as Raspail, in his Organic Chemistry, has the following sentence :-" Organization, on the contrary, is, as it were, a crystalliza tion which gives a tendency to assume a vesicular form, and produces a cell capable of absorbing the gases necessary both for its vesicular development, and for the reproduction of others similar to it. This cell is a laboratory where gases are condensed into liquids, which in their turn are organized into textures. It is in short, an organized body." And in one of his papers in reply to Dutrochet, published a short time subsequent to his New System of Organic Chemistry, is contained the fol lowing startling expression. "Give me a cell capable of producing others, and I will form an organised world." These are not his exact words, and I cannot at this moment lay my hands on the paper in which this remark is contained; but the idea, to which the above sentence gives birth, is the same as that contained in the original. 2 The time of this appearance, however, varies much in different chicks, as also does the time of the appearance of the different structures and organs. This is not the effect of any external cause, as it is observed when the eggs are put into the hatching house at the same time, and removed together after having lain there for a certain period, and when consequently all external circumstances must have been the same to each and all of them.

1 Raspail's Chemistry, translated by Dr Wm. Henderson, p. 10.

I shall divide the following description into three stages. In the first, the different changes which the blood corpuscles present from their first appearance, until their central part has become granular. Second, from the gradual disappearance of this granular structure, to the flattening of the sides of the corpuscle. And, thirdly, the changes which they present whilst passing from the circular to the oval form.

First Stage. On placing the blood removed in the manner above described under the microscope, a number of small granules are seen floating about in the field; these enlarge and become clearer in the centre; this enlargement goes on very rapidly, and when they have gained to about twice their original size, the central clear part becomes dull. This dulness slightly increases, and in a short time it is seen to be distinctly granular, whilst the borders are observed to be well defined, smooth, and clearer than the central part. The enlargement of these bodies, with the granular appearance of their centre, seems not to depend on the aggregation of granules round a central one, but on a property which they have in themselves of enlarging and of presenting that figure. In the field, a number of these objects are frequently seen close together, and many of them appear more granular than the rest. During all this time they are quite spherical, and are of good consistence, as they do not lose their form by considerable pressure.

Second Stage. The central portion becomes gradually less opaque, and gradually ceases to appear granular, the external portion at the same time separating in some degree from the central part. This part I shall subsequently call nucleus. The blood corpuscle in this stage of development has the appearance of a slightly flattened round cell, formed of a somewhat delicate but elastic membrane, with a nucleus in the centre. At this time, a number of these bodies, being close to each other in the field, present a yellowish colour. This colour seems to me to reside in the space between the nucleus and membrane. Of this, however, I

am not certain. During the time that the elastic membrane is separating from the nucleus, the intervening space becomes flattened. This flattening goes on to such an extent, as to leave a depression between the nucleus and border. The edges of the corpuscles are flat, appearing as if they had been cut off abruptly. The convexity of the nucleus, the flattened edges of the corpuscle, and the concavity intervening between these two parts, are distinctly seen when any of these bodies, at this stage of development, are observed turning upon themselves. During all these changes the blood corpuscles are perfectly circular.

Third Stage. One side of the corpuscle is seen gradually to elongate itself, until it has gained a pear-shaped appearance; the opposite side then elongates itself in the same manner, and VOL. FOR 1842, NO. IX. 5 Q