CONNECTIVE TISSUES. 25 
What connective tissue cells are found in this kind of tissue ? 
The flattened or lamellar cells. They are very thin and are 
wrapped around the fibres, making the structure look as though it 
were composed of branching cells with anastomosing branches. 
Where is reticular tissue best seen ? 
In lymphatic glands; but as the interstices in the network of fibres 
are filled with round or lymphoid cells, the reticular structure is so 
covered that it cannot be seen unless the round cells are washed out. 
Describe lymphoid tissue. . 
It is a reticular tissue having its interstices filled with lymphoid 
cells. 
What is the appearance of lymphoid cells ? 
They are small round cells in which the nucleus is very large, and 
the amount of protoplasm relatively small. 
In what parts is lymphatic tissue found ? 
Lymphatic glands, tonsils, and the solitary and agminated follicles 
in the small intestine. 
What is the macroscopical appearance of cartilage ? 
It may be of a pearly white or of a yellowish color, it is firm and 
dense, and yields to pressure or torsion, resuming its former shape 
when the constraining force is removed. 
What is the perichondrium ? a 
It is a moderately vascular fibrous membrane which covers all car- 
tilages except those at the joints. 
What are the varieties of cartilage? 
Hyaline, yellow elastic, and white fibrocartilage. 
Into what classes may hyaline cartilage be divided? 
Temporary and permanent. 
Where is temporary cartilage found? 
The skeleton of the embryo is made up in great part of hyaline 
cartilage, which later becomes ossified and forms true bone. 
What are some of the permanent cartilages? 
Costul cartilage, articular cartilage on the articular surfaces of 
bones, and the tracheal cartilages in the trachea, 
