248 GENERAL ANATOMY. 



they terminate; because primitively the testicles and ovaries 

 were situated near the kidneys. 



365. The number, the volume, and consequently the 

 amount of vessels, as well as the quantity of liquid they carry, 

 vary equally in the different organs. The greater number of 

 organs receive several vessels of each kind: such are, for in- 

 stance, the muscles, the bones, the encephalon, the stomach, 

 the intestines, the uterus, &c. ; some have only a single arte- 

 rial and a venous trunk; such are the spleen, the kidneys, &c. 

 The vessels, almost always, greatly subdivide at the surface of 

 the organs before penetrating into their interior, as is observed 

 in the brain, the bones, the muscles, &c.; sometimes they enter 

 into an organ through one single point, and subdivide within 

 its mass, such as, for instance, the spleen, the testicles, &.c. 



The amount of the vessels, resulting from their number, and 

 from their volume, as well as the quantity of the fluid con- 

 veyed through them, vary greatly. The most vascular parts 

 are the lungs, then the tegumentary membranes, the pia-mater 

 and choroid ; then the glands, the follicles, the vascular gan- 

 glions, the cortical substance of the brain, and the nervous 

 ganglions; then the muscles, the periosteum, the adipose tissue, 

 the medullary nervous substance, the bones, and the serous 

 membranes; then the tendons, the ligaments; finally, the carti- 

 lages and the arachnoid are but little so or not at all; and the 

 epidermis, the nails, the hair, the ivory, and the enamel of the 

 teeth, seem to be altogether deprived of vessels.* 



366. Having arrived in the tissue of the organs, and hav- 

 ing attained a degree of tenuity more or less great, the vessels, 

 by their divisions and subdivisions, by their direction, and by 

 their anastomoses, form a very minute net- work, the form of 

 which, although very diversified, is always the same in the same 

 parts. They present arborizations in the intestines and epi- 

 didymis, stars on the liver, tufts on the tongue, tendrils in the 

 placenta; they have the form of a bottle-brush in the spleen, 

 resembling a bundle of rods in the muscles, curls in the testicles 



* See Soemmering', de Corp. human, fabric:!, V. iv. tmgiologia, 1800. G. 

 Prochaska, Disquisitio anat. physiol. organismi corp. hum, &c. foennae, 1812. 

 Cap. ix. De vosis scmguintis capillaribus, &c. 



