162 
MR. TOYNBEE ON THE ORGANIZATION AND NUTRITION 
The First Class of Non-vascular Animal Tissues. 
Of Articular Cartilage and Fibro- Cartilage. 
The tissues which I have placed in the first class are articular cartilage, and fibro- 
cartilage ; but in reference to the latter, the cartilaginous portion only can be consi- 
dered as non-vascular. These tissues are analogous to each other in their situation, 
structure, mode of nutrition and functions. Each of them forms a part of joints, and 
is subject, in the performance of its functions, to concussion and compression, and is 
composed of corpuscles or cells possessing similar characters. Although they are 
properly considered as non-vascular tissues, they appear to be pervaded by blood- 
vessels at an early period of their development, or perhaps it would be more correct 
to say, that as growth proceeds, the cartilage increases, so as to occupy the space 
which had previously been permeated by vessels. 
I have been able to demonstrate that vessels are never found within these carti- 
lages when fully developed, but at that period vessels form convolutions in their 
immediate vicinity. These vessels are separated from articular cartilage at adult 
age by a layer of bone, and in fibro-cartilage, at the same period, they uniformly 
terminate within the boundary of its fibrous tissue. Over a certain portion of the 
free surface of both of these tissues blood-vessels extend, but they do not penetrate 
into their substance. 
The investigations which are about to be detailed, lead, I think, to the certain con- 
clusion, that articular cartilage in the adult state is principally nourished by fluid 
derived from the vessels of the cancelli of the bone to which it is attached, which 
exudes through the coats of those vessels, and makes its way into the substance of 
the cartilage through the intermediate lamella of bone. The cartilage of fibro-carti- 
lage is nourished in like manner by liquor sanguinis, derived from vessels situated 
in the contiguous fibrous portion. The vessels ramifying in a certain extent of the 
free synovial surface of both these species of cartilage contribute doubtless to their 
nutrition, but not to near the same extent as do the vessels of the opposite side. 
With respect to the actual process of nutrition in these cartilages, I shall only observe 
here, that the cells of these structures must be regarded as having the function which 
has been ascribed to those of all non-vascular tissues, viz. that of promoting the cir- 
culation of, and modifying, the nutrient liquor. In connection with this process, how- 
ever, it will be seen, that articular cartilage presents in its adult state very minute 
canals, which may be regarded as existing for the reception of the nutrient fluid, and 
Owen’s Odontography : — “ But since every secretive process, and the development of the primordial cells of 
every tissue are due to changes produced in the liquor sanguinis, transuded from and beyond the sphere of the 
ultimate capillaries, the absence of these vessels in the dense dental substance is as little conclusive against its 
vital and organized nature, as it would be to prove the inert condition of the germinal membrane of the ovum 
before the thirtieth hour of incubation.” — p. 13. 
