In reference to this supposed line, Dr. Henry Beates, Jr., President of the Philadelphia Clinical Society, of this city, an expert pathological and histological microscopist, and a gentleman whose learning and scientific attainments will not be questioned by any man, says:

"A microscopic study of the section of embryonic tooth you sent me discloses the existence of a space between the dentine and the enamel. At the base of the enamel, i. e., the surface of the enamel rods next to the dentine, there exists an apparent line or membrane. Below this line is a somewhat homogeneous or colloid looking substance, evidently of much less consistency than the structure above. Above this line is the enamel, more fully developed and already hardened. At first glance I considered this line to be a membrane similar to the membrana propria of glandular tissue, but, upon close study, was surprised to find its existence a mere optical delusion, dependent upon an angular displacement of the inferior or softer portions of the enamel rods-so there is no line or membrane in reality at all. The inferior, softer and apparently more homogeneous substance is certainly the newer or primarily secreted enamel substance. The absence of a membrane, the physical characteristics of the enamel, the position of the softer and more indurated enamel, all tend to confirm the view that the enamel is formed at the dentine, and develops and becomes indurated as it is elevated by the development of new structure below, precisely as in the case of epidermal cells. I believe the teeth to offer no exception to the general physiological law, and consider the doctrine which teaches that

enamel is formed upon the dentine and grows by deposits from above, as erroneous as the announcement that a membrane or line exists in the middle of the enamel rods."

DEAN'S LEGROS AND MAGITO describes the under layer of the enamel in the following language:

"The prismatic cells of the concave surface of the enamel organ (the enamel cells or ameloblasts) offer some peculiar characteristics to which we call your attention. Originally identical with those of the lowest layer of the malpigian stratum, from which they are directly derived, these cells, besides increasing in length, experience some important changes in form. The extremity that is directed toward the centre of the organ becomes long and slender, forming processes which unite with or are continuous with the filiments that proceed from those neighboring cells which constitute a portion of the enamel organ, known as the stratum intermedium. The opposite or peripheral extremity, that is to say the base of these cells, presents the regular prismatic form of a hexagon. If, now, we examine an underanged layer of these prismatic cells or ameloblasts magnified about 400 diameters, we shall find that the free margin of this layer (that is to say, the part that corresponds to the base of these cells) appears clearer than the bodies of the cells themselves, and in a fresh preparation seems like a continuous line. If, however, a like examination be made of some hardened preparation, or if careful means be taken to detach this marginal line, which the edge of the section of the plateau represents, from the base of it, it will be found that it can be subdivided into as many sections as there are cells in the layer. And yet some preparations may be met with in which more or less of these clear lines become detached in the form of a shred ribbon. It is this strip, which is evidently made continuous by artificial means, that has given rise to the hypothesis that a membrane invests or lines the concave face of this stratum of cell-ameloblasts. We shall see, moreover, in examining these peculiarities in detail, that this appearance is not specially and exclusively confined to the cells of the enamel organ, since it exists wherever we find the prismatic cells provided with what has been termed a plateau. The prismatic cells of the intestines are known to be thus supplied."

You will notice that the above quotation speaks of the "enamel cells," "ameloblasts," cells of the enamel organ," as all being on the lower strata. It also uses the analogy of this lower layer of the enamel organ with that of the prismatic cells of the intestines. No one will dispute that these cells constantly undergo multiplication, and the new cells thus produced push outwards those which have been previously formed. It is one more point in favor of my position, that the enamel is not built by deposit from above, but pushed upwards by a multiplication of cells from below.

Diagram No. 9, which appeared in the April number of the Dental Cosmos for 1884, page 197, is by Dr. J. L. Williams, an advocate of the "accepted theory," and a gentleman who, by reason of his eminent ability, has been selected to write a chapter upon the development of the teeth, &c., in the forthcoming work on Dentistry by American Authors.

a. Epithelial layer of mucous membrane.

b. c. Breaking up of epithelial cord and formation of globular bodies, from which supernumerary teeth are said to be developed.

d. Stellate cells of enamel organ.

e. Columnar cells, from which enamel cells are developed. f. Dentine germ.

g. Ossification of inferior maxilla.

This is a fair representation of the enamel organ, though diagramatical as all plates are. Let us, however, compare it with the diagrams of other epidermoid structures. Dr. Williams describes e as columnar cells from which enamel cells are developed. This is true. The Stratum Malpighii in the diagram of the skin represents the columnar cells from which the epidermis is developed. b, in the diagram of the nail, shows the columnar cells from which nail is developed, and m, in the diagram of the hair, shows the cells from which the hair is developed.

In all these structures it will be seen that these columnar cells are of the Malpigian layer of the epiderm, and originally from the epiblastic layer of the embryo. All authorities agree in stating that at the bottom (where this layer exists) there is a continual multiplication of these cells, each successive series being followed and pushed from their original place by others." I cannot, therefore, accept the theory, groundless in proof and supported, as far as I can see, only by assertion, which selects a single inoffending tissue of the body, and in referenee to which entirely reverses this formative order. There are legitimate discoveries possible in the field of Histology. As a science, it is yet in its infancy. But a discovery to support the truth of which, it is necessary, magic-like, to change a fully developed cell into an embryonal state, and wholly and completely set aside every law of nature, should at least be looked upon with suspicion, if, indeed, it should not be charged with being an enthusiastic prostitution of a great science.

The facts I have produced, and others I might mention did space permit, have led me to question the truth of the theory that these particular columnar epidemic cells of the enamel act diametrically opposite to all other epiblastic structures in the animal creation. There is no reason why it should be so; there is no proof that it is so, and on account of the lack of these two essentials to every truth I was led to investigate the theory, and now hold that it is not so.

AN ANOMALOUS FACIAL MUSCLE.

BY C. LEVIS BOWER, PH.G.

In a recent dissection made by me at the Philadelphia School of Anatomy, I found an anomalous muscular slip in the oculo-nasal region that appears to merit description, since it has not been seen previously by several anatomists to whom I have shown it.

It arose from the malar bone just in front of the zygomaticus major, and, after running obliquely downward parallel to this muscle for about half an inch, turned upward toward the orbicularis palpebrarum, beneath the middle of which it divided into two portions. The upper or wider portion seemed to run under the orbicularis of the lower lid, and its fibres afterwards became visible and were lost in the orbicularis fibres of the upper lid.

The lower portion was inserted or lost in the outer side of the levator labii superioris alæque nasi, near its middle.

There was a distinct interval between the two bands before they reached their points of insertion.

It presented no tendon; nor was there any loop of fascia noticed. The zygomaticus minor crossed the anomalous muscle on a more superficial plane.-The Polyclinic.

TAKING THE BITE.

FRANK R. FABER, D.D.S.

Mechanic to the Profession, Philadelphia, Pa.

One of the knotty points connected with Dental Mechanism is the getting of a correct bite. As much annoyance and inconvenience in this one point is to be found, as in any other particular part of the whole operation, not only to the dentist who patronizes the mechanical laboratories, and who stands more chance of inconvenience in this way, but also the individual who does his own mechanical work, and although he is familiar with the mouth, and thinks he knows it in its full detail, is very often surprised to find the bite incorrect when the case is finished. It is very clear to the minds of my readers that although the apposition of the jaws on the articulator may look wrong to the dental mechanic, he never having, "or in most cases never having" seen the patient, has nothing else left to do but mount the teeth in wax, and get them ready for trial in the mouth. While on the other hand, if the man who handles the mouth has had some experience in this direction, he can, in a majority of cases, satisfy himself with a glance as to whether it is right or wrong, and if wrong a fresh attempt made.

The man you occasioually meet who never has any failures in taking bites, you can very quickly understand does not have many to take; he is the same man whose fillings never fail, and whose plates are always a success. There are no set rules for correctness in this direction, or if there are I have never found them. A great deal of opposition is given to the dentist by the patient, some of them in their good natured endeavors to get it right, others by their stupidity and assurance, "they know how;" particularly is this noticeable of the large-mouthed female patient, who wants to close and purse up her lips in imitation of a Miss of sixteen. It does not do to get out of patience, but it is certainly exasperating when a patient sits in the chair to have a bite taken for a partial set of teeth, and whose occlusion of natural teeth is normal, persists in bringing them end on end, upper and lower, and at last getting them right, "this time by mistake." The hardest patients to get along with are those to whom you give the most instruction, and for this reason when you are getting ready to take the bite, and taking it, talk about anything else but what you are going to do next; talk about something-anything to divert the patient's attention from what you are doing.

The prime movement is to get a set of teeth that will be finished when they are put into the mouth. It will impress the patient more favorably than if there be any grinding and fitting to do, and it is never as satisfactorily done on the finished plate as it can be in the course of construction. The ideas which I propose to give are not the result of an individual practice by any means, but are the points which have