122 AKTHROLOGY. 



between the vertebral ceutra. SiraPlform or InvesHvg, wl'.e'i) it 

 clothes the parts of hopes over which the tendons of muscles play, 

 sometimes existing in the tendons themselves. 



This tissue is dullish white, opaque, and. for the mofit part. 

 devoid of perichondrium | it is vascular, but its blood -vefisels are 

 few, and confined to the fibrous tissue, which exists as interwoven 

 bundles of fibres, with cartilage cells interspersed amongst them. 

 In the variety connecting vertebras, it consists of concentric rings 

 of fibrous tissue, enclosing a soft elastic centre, partty mude up of 

 cartilixge cells, and often regarded as the remnant of the itotochord. 

 In fishes this portion is soft and pulpy, filling the opposing con- 

 cavities of the vertebral centra. Its power of cohesit>n is very 

 great, surpassing even that uf bone. 



Yellow eladic fihro-cartilage is found in the epiglottis or vaive 

 which closes the principal air-tube ; it forms part of the frame- 

 work of the ear. and of the Eustachian tubes which convey air 

 to the tympanum. The fibres forming the matrix aro similar to 

 those of yellow elastic tissue. 



Cellular or ret'lcular cartilage is found in the v;ar of some 

 small rodents, and in the bat. It consists of cells devisaly packed, 

 and apparently without a matrix : the walls of tKe cells thus 

 coming into contact, give it a net- like appearance, hence the 

 name reticular cartilage. 



CONNECTIVE TISSUE. 



In one form or other this tissue is found in t-W }>arts of the 

 body. The chief varieties are the areolar and the fibrous ; the 

 former serving as a connecting medium, and support to the various 

 organs, and to the structures of which they are formed. It 

 appears as a loose translucent mesh, its interwoven bundles form- 

 ing spaces termed the areolae or cells, hence its name Gellular or 

 Areolar Tissue. It consists of minute lamina and filaments 

 mixed with small fibres of elastic tissue, while cells, or their 

 remains, nuclei and walls, are also present, the whole embedded 

 in a perfectly transparent basis. Other slightly varyiug forms 

 are termed Betiform,, Gelatinous, &c., while the coniiecti^'e tissue 

 of the brain and retina has received the name of Neuroglia. 



White fibrous tissue has a similar structure to the above, but 

 is dense, strong, and practically non-elastic. Tb& filaments which 

 form it are mostly parallel and wavy in their arrangement. It 



