332 Glossary 



Larynx. — A muscular and cartilaginous structure situated at the 

 base of the tongue and connecting with the windpipe (trachea). 

 It is the organ of voice. 



Lesion. — Any hurt, wound or local degeneration. 



Leucocytes. — White blood corpuscles. 



Lumen. — A transverse section of the clear space within a tube. 



Lymphatic. — Pertaining to or containing lymph which is a trans- 

 parent slightly yellow liquid which fills the lymphatic vessels. 

 It corresponds in some respects to the serum or liquid portion 

 of the blood. 



Mammal. — Any vertebrate animal which suckles its young. 



Melanosis. — Pertaining to an abnormal deposit of pigment. 



Mesentery. — The fold of peritoneum attached to the intestines. 



Metamorphosis. — In insects the change from larval to adult form 

 as from caterpillar to butterfly. 



Micro-organism. — ■ Any minute (microscopic) animal or plant. 

 Often used in referring to bacteria or germs. 



Mite. — A small artlu-opod somewhat related to spiders (cf. 

 Fig. 40). 



Morphological. — ■ Pertaining to the forms and structures of or- 

 ganized beings. 



Mucosa. — The mucous membrane. 



Mucous membrane. — The lining of the internal cavities of the body. 



Mucus. — The viscid secretion of certain (mucous) glands. 



Mycelium. — The thread-like portion of a fungus (cf. Fig. 53). 



Nacreous. — Resembling mother-of-pearl. 



Necrosis. — Death of a tissue. 



Necrotic. — Pertaining to dead or decaying tissue. 



Nictitating membrane. — The third or lateral eyelid in birds and 

 some related forms, springing from the inner or anterior border 

 of the eye and capable of being drawn across the eyeball. 



Nucleus (pi. nuclei). — A spherical body within a cell. The nucleus 

 is essential to the life of the cell. 



(Esophagus. — That portion of the alimentary canal between the 

 mouth (pharynx) and the crop. 



Oral. — Pertaining to the mouth. 



Ovary. — The female sexual organ in which the eggs develop. 



Oviduct. — The tube through which the egg passes from the ovary 

 to the cloaca. 



Ovum (pi. ova). — The egg, particularly while in the ovary, 

 (cf. Fig. 60). 



Panophthalmia. — Inflammation of all the structures or tissue of 

 the eye. 



Papilla. — A smaU nipple shaped elevation. 



