Volume 1

The collected papers of Sir W. Bowman, Bart., F.R.S / edited for the committee of the "Bowman Testimonial Fund" by J. Burdon-Sanderson and J. W. Hulke.

  • Bowman, William, Sir, 1816-1892.
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: The collected papers of Sir W. Bowman, Bart., F.R.S / edited for the committee of the "Bowman Testimonial Fund" by J. Burdon-Sanderson and J. W. Hulke. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    plexus is interposed between the efferent vessels of the Malpigliian bodies and the veins. The efferent vessels of the Malpighian bodies are always solitary and never inosculate with one another : each one is an isolated channel between its Malpighian tuft, and the plexus surrounding the tubes. They are formed by the union of the capillary vessels of the tuft, and emerge from its interior in the manner already explained. After a course of variable length they open into the plexus. Their size is various. In general, they are smaller than the terminal twig of the artery, and scarcely, if at all, larger than the vessels of the plexus into which they discharge themselves. But where the Malpighian tuft is large, the efferent vessel is usually large also, and divides into branches before entering the plexus. This is eminently the case with those situated near the base of the medullary cones, where the medullary and cortical portions of the organ seem to blend. The efferent vessels from these large Malpighian bodies are often three or four times the diameter of those of the plexus, and take a course towards the pelvis of the kidney between the uriniferous tubes. They were formerly mistaken for tubes. They branch again and again in the manner of arteries, and form the plexus with long meshes which invests this^ part of the tubes. Some of the veins springing from this plexus form i lie well-known network on the nipple-shaped extremities of the cones, around the orifices of the tubes, and thence take, with the remainder, a backward course, like- wise parallel to the tubes, to empty themselves into venous branches that lie about the bases of the cones. These also, when injected, have been mistaken for tubes. The other venous radicles are dispersed at about equal distances throughout the cortex of the kidney, and each receives the blood on all sides from the plexus surrounding the convoluted tubes. When these venous radicles are congested, or injected, they mark out the surface of the cortical substance into lobules not very unlike those of the lobules of the liver. On the Horse's kidney, especially, this may be often well seen. Each lobule contains many tortuous ducts with their capillaries, but the convolutions of any one duct are not confined to a single lobule. These radicles unite in an irregularly arborescent figure, anastomose and form the several branches of the renal vein. Those on the surface, especially of the human kidnej^, have a tendency to converge towards a central vessel, which then dips into the interior, and runs, like the rest, towards the hilus. Thus are formed the stellated vessels of anatomists, often conspicuous in diseased specimens. Between the sprawling arms of these Stellas the convoluted tubes, with their plexus, come up to the surface (Plate IV., fig. 11), but the Malpighian bodies are rarely, if ever, visible quite on the surface. They are always covered in by convolutions of the tubes. The veins from the capsule and surrounding fat join the renal vein in some part of its course. It is probable that the capillaries of the vasa vasorum, within the substance of the organ, pour their blood into the capillary plexus surrounding the