Although we deem it necessary to refer specially to the anomalies of these vessels, we must observe that we are entering upon a field of inquiry which has hitherto only been partially cultivated in reference to the general anatomy of certain processes. In the following remarks, we purpose referring to what has been already stated, both generally and specially, regarding the diseases of the vessels.

We therefore omit to notice the formation of new vessels, which occurs under certain conditions, as well as the atrophy of the capillaries, which presents itself under other conditions, and proceed at once to the consideration of the following anomalies.

1. Anomalies Of Calibre And Especially Dilatation

Under this head there are commonly placed Aneurism by Anastomosis, Teleangiectasis, Fungus hoematodes.

Aneurism by Anastomosis consists, according to J. Bell, in dilatation of the small arteries and their anastomoses, giving rise to a pulsating, more or less defined, tumor; it is separated from the venous system by normal capillaries; the dilatation sometimes, however, extends to these vessels, and, finally, to the veins.

Teleangiectasis, on the other hand, consists in a dilatation of the capillaries, and appears sometimes in the form of slightly elevated patches, which may be smooth or may present inconsiderable nodules, and sometimes in the form of roundish, nodular, and lobulated smooth tumors, which are either of a bright-red color, or of a darker, purple or cherry-red tint, and are either tough and elastic, or soft, and of a doughy consistence. They are capable of swelling and of undergoing a considerable collapse; and hence the name of erectile tumors; which Dupuytren has applied to them. We must, however, remark, that there is no analogy between the arrangement of their vessels and that which occurs in the erectile organs. Teleangiectasis may certainly in some cases be developed chiefly on the arterial side of the capillaries, and in other cases on the venous side; and its form may in part be referred to its position, for we regard those that extend superficially as chiefly of an arterial nature, and those which become developed into tumors as especially of a venous nature. It occurs most commonly in the tissue of the general integuments, and in the subcutaneous cellular substance; and further, besides those cases in which it is continued from these to the neighboring mucous membranes, it is also developed independently upon the mucous membranes, as, for instance, those of the intestinal canal; and, lastly, in rare cases in other tissues, as in the muscular substance, etc.

It is in general congenital, although it is capable of further development after birth. In some rare cases it even originates in later periods of life.

The structure of congenital teleangiectasis is mainly to be referred to the transition of the dilated extremities of arteries into saccularly formed dilated venous radicles, from whence a varicose condition extends for a considerable space to the larger ramifications. The convolution of dilated vessels is held together by means of a loose and partially embryonic cellular substance. The above remarks give the main points of the opinions hitherto maintained in reference to dilatation of the minute vessels and the true capillaries - more especially when the disease is of a congenital character. But these views undoubtedly require much consideration. A similar observation applies equally or even more forcibly to the teleangiectases, which are observed to arise in different and more advanced periods of life, as a consequence of repeated inflammations, and of loosening and rarefaction of the tissue in the neighborhood of ulcers, and in and around the most various new formations, etc. The dilatation of the existing capillaries, which has commonly been considered as a sufficient cause for this anomaly, is certainly, in many cases, inadequate to explain its existence, and we find that, in addition to this condition, there occurs simultaneously a new formation of vessels, - a subject which we have already considered generally in its relation to the original vascular apparatus.

Fungus hoematodes, which does not consist in a mere dilatation of the vessels, has been fully noticed as a secondary formation in the General Anatomy.

The present notice would be incomplete, were we to omit all reference to a morbid structure, which has been generally regarded as belonging to the teleangiectases, and from which it has been supposed, on somewhat obscure grounds, to be developed. It does not appear to us to belong to these affections, and we are rather disposed to regard it for the present, at all events, as a new formation. It includes cavernous tumors, having a cellular structure similar to that of the corpora cavernosa. They are composed of a cellulo-fibrous tissue and a lining membrane investing the interstices, and enclosed in a dense cellular capsule. These structures admit of being separated from the organs in which they are seated, are capable of tumefaction, and may be injected by a vein. They occur in the form of the so-called secondary spleens (which, according to Andral, are of a placenta-like texture) in the subcutaneous cellular tissue, and are of especially frequent occurrence in the liver; we have also observed them in the cranial bones, and in the pia mater. They sometimes contain sand-like concretions, which may be regarded as similar to phlebolites.

2. Separations Of Continuity

These are very numerous in the capillaries, or arise from cuts or from lacerations induced by contusions and shocks. They result in an extravasation of blood into the tissue, and hemorrhage externally or into different cavities and canals.

A higher degree of interest must be attached in a pathological point of view, - 1, to spontaneous laceration of the capillaries in apoplexies (parenchymatous hemorrhages) of the different organs and tissues, arising from hyperemia (vascular apoplexy), which, although formed in the usual manner, has been developed beyond a certain limit; - and 2, to spontaneous lacerations resulting from a morbid brittleness of the walls of the vessel, or from a similar condition of bogginess in the tissue affected by the hemorrhage, as, for instance, the substance of the uterus.