674 COMPARATIVE ANATOMY 



fasciculus. One of the divisions of a funiculus of the spinal cord 



femur. The thigh bone. 



fenestra cochleae. The round window of the internal ear. 



fenestra vestibuli. The oval window to which the stapes bone is attached. 



fertilization. The union of sperm and egg nuclei within the ovum. 



fetus. The child in the womb after the end of the third month. 



fibril. A cytoplasmic thread. 



fibrin. The clot-forming substance of the blood. 



fibrocyte. A flat elongated connective tissue cell. 



fibula. The outer shin bone. 



filum terminale. The thread-like termination of the spinal cord. 



fimbriae tubae. The fringe-like end of the uterine tube. 



fission. Asexual division into equal parts. 



fissure. A deep fold of the cerebral cortex which involves the entire thickness of 



the brain wall. 

 fistula. A deep ulcer-like opening, usually into a hollow organ. 

 fiabellum. A fan-like set of radiating fibers in the corpus striatum. 

 flagellate. Having whip-like processes. A protozoon with flagellae. 

 flagellum. A whip-like protoplasmic process of a cell. 

 flame-cell. An excretory cell having one or more flagellae. 

 flexion. The condition of being bent. 

 flexure. A bend or fold. 



flocculus. A small lobe on the lower side of the cerebellum. 

 floor plate. The flooi- of the neural tube, 

 foliate papillae. Leaf-like folds on the sides of the tongue. 

 follicle. .\ small secretory sac or gland. The integumentary sac enclosing the base 



of a hair or feather. 

 fontanelle. One of the unossified regions in the skull of the infant. 

 foramen. A small opening, usually in a bone. 



fornix. A band of commissural fibers ventral to the corpus callosum. 

 fossa. A pit or depression. 

 fovea centralis. A pit in the macula lutea of the retina where the layer of nerve fibers 



is lacking. 

 freemartin. The sterile female twin of a male calf. 

 frenulum linguae. A median fold between tongue and mandible. 

 friction-ridge pattern. A concentric arrangement of fine ridges on the hands and 



feet. 

 frontal. The bone of the forehead. A sectional plane which divides a bilateral body 



into dorsal and ventral divisions. 

 function. The normal activity of an organ. 

 fundus. The part of a hollow organ opposite its opening. 

 fungiform. Mushroom-shaped. 

 funiculus. One of the three chief divisions of white matter on the sides of the cord. 



gall bladder. The pear-shaped sac which stores the bile secreted by the liver. 



gamete. A sexual cell — ovum or spermatozoon. 



ganglion. A functional group of nerve cells outside of the central nervous system. 



Gartner's duct. The rudiment of the Wolftian duct in the female mammal. 



Gasserian ganglion. The semilunar ganglion of the trigeminal nerve. 



"gastraea" theory. The theory that the gastrula stage represents a coelenterate stage 



in vertebrate phylogenesis. 

 gastric glands. The glands of the stomach wall. 



