106 THE HUMAN BODY. 



cordingly known as lymph canaliculi. In addition to the 

 fixed branched connective- tissue corpuscles there are often 

 found other cells, when living connective tissue is exam- 

 ined. These cells much resemble white "blood corpuscles, 

 and probably are such which have bored through the walls 

 of the finer blood-vessels. They creep about along the 

 canaliculi by means of their faculty of amoeboid movement, 

 and are known as the "wandering cells." During in- 

 flammation at any point their number in that region is 

 greatly increased. 



Subsidiary Varieties of Connective Tissue. In various 

 parts of the Body are connective-tissue structures which 

 have not undergone the typical development,, but have de- 

 parted from it in one way or another. The cells having 

 formed a non-fibrillated intercellular substance around 

 them, development may go no farther and the mass remain 

 permanently as the jelly-like connective tissue; or, as in 

 the vitreous humor of the eye (Chap. XXXI.), the cells 

 having formed the soft matrix, may disappear and leave the 

 latter only. In other cases the intercellular substance 

 disappears and the cells branching, and joining by the ends 

 of their branches, form a network themselves, nucleated or 

 not at the points answering to the centre of each originally 

 separate cell. This is known as adenoid connective tissue. 

 In other cases the cells almost alone constitute the tissue, 

 becoming flattened, closely fitted at their edges,, and united 

 by a very small amount of cement substance. Membranes 

 formed in this way lie beneath layers of epithelium in 

 many places and are known as basement membranes. In 

 brain and spinal cord, protecting and supporting the nerve 

 tissues, are found branched cells forming the neuroglia. 

 They are not true connective tissue, but correspond to cells 

 of the horny layer of the epidermis, shut in when the 

 medullary canal was closed in the embryo. 



Elastic Cartilage, and Fibro-Cartilage. We may now 

 return to cartilages and consider those forms which are 

 made up of more or less tme cartilage mixed with more or 



