The assemblage of the fibres forms, according to anatomists, layers which they have considered as in juxta-position, and held together by little pins according to some, and by the interlacing of fibres according to others. These osseous layers do not appear to me to exist in nature. All the fibres of the compact texture adhere to each other, cross and form a whole that we cannot conceive of in this manner, and which besides does not accord with the irregularity of the distribution of the vessels. Art separates here fibres layer by layer, as it is done in a muscle, in a ligament, &c.; but these layers are wholly factitious; to exhibit the bones as formed by an union of these layers is to give a very inaccurate idea of their structure. It is still more inaccurate to consider these layers as attached to each other by osseous pins, by attraction, or by a glutinous matter which serves as a glue. All these ideas, contrary to anatomical examination, suggested by a false application of the laws of the adhesion of inorganic bodies to the adhesion of organized fibres, now belong only to the history of physiological errors. There is a circumstance, it is said, that very evidently proves the lamellated structure of the bones, it is their exfoliation. It is true that often very distinct layers are separated from the living bone, but these layers are only the product of exfoliation itself. Then in fact the bone dies on the surface; the superficial vessels receive no more blood; this fluid is stopped under the portion deprived of life, the exhalation of the phosphate of lime ceases there, every kind of sanguineous, exhalant and absorbent vessel is destroyed; a slow inflammation, with suppuration, comes on, and fixes the line of demarcation; and as this line is often at the same place, all which is above it becomes an inorganic layer which gradually falls off, and preserves its osseous solidity, because the dead absorbents were not able to remove the phosphate of lime. Besides, nothing is more common than to see exfoliation take place not by layers, and the bone afterwards exhibit an unequal surface, the effect of the inequality of the thickness of the exfoliated portions. Finally, exfoliation often takes place in a direction opposite to that which the layers are thought to have; this is what we see in the separation of the extremity of the long bones, that have been exposed to the air or too much irritated after amputation, in the shedding of the horns of animals, &c. Let us consider the compact texture as an assemblage of condensed fibres, not separated by layers, which we can only consider as imaginary.