GLOSSARY 439 



endoderm. The innermost germ layer. 



endolymph. The liquid contained in the membranous sac of the inner ear. 



endometrium. The mucous lining of the uterus. 



endoneurium. The connective tissue which subdivides a nerve into funiculi. 



endoskeleton. The internal skeleton as distinguished from the dermal skeleton. 



endostyle. A ciliated groove in the floor of the pharynx of lower chordates. 



endothelium. The thin membrane which lines blood vessels and lymphatics. 



end-plate. The expanded termination of a motor nerve on a muscle fiber. 



ensiform. Shaped like a sword. 



enterocoele. A mesodermal cavity formed as an outpocketing of the endoderm. 



enteron. The cavity of the alimentary canal. 



enterokinase. An enzyme secreted by the small intestine which converts trypsinogen 



into tripsin. 

 enzyme. A catalytic organic compound which facilitates chemical changes such as 



the splitting of foods into simpler substances in the alimentary canal. 

 eosinophile. A leucocyte with an affinity for eosin. 

 epaxial. Dorsal to the vertebrate axis. 



ependyma. The lining membrane of the central nervous system. 

 epibranchial organs (ganglia or placodes) . Ectodermal masses above the gill-pouches of 



vertebrate embryos. 

 epicardium. The outer covering of the heart. 

 epidermis. The outer ectodermal layer of the skin. 



epididymis. The mass of convoluted tubules and duct attached to the testis. 

 epiglottis. The lidlike structure which covers the entrance to the larynx. 

 epimere. The dorsal portion of the mesoderm. 



epinephrine (adrenin). The hormone secreted by the medulla of the suprarenal. 

 epineurium. The connective tissue covering of a nerve. 

 epipharynx. The nasal portion of the pharynx. 



epiphysis. The terminal portion of a long bone. The pineal organ. 

 epithalamus. The dorsal portion of the diencephalon. 

 epithelium. The tissue which covers a surface. 

 epitrichium. The outer layer of the fetal epidermis. 

 epoophoron. A rudiment of the mesonephros near the ovary. 



ereptose ferepsin). A peptone-splitting enzyme secreted by the intestinal mucosa, 

 erythrocytopoietic tissue. Tissue forming red blood corpuscles. 

 esophagus. The portion of the alimentary canal between pharynx and stomach. 

 ethmoturbinals. The superior and middle turbinated bones, 

 ethmoid. The sieve-like bone at the front of the skull. 

 eunuch. A castrated individual. 



eustachian tube. The passage which connects the tympanic cavity with the pharynx 

 excretion. The elimination of liquid wastes. 



exoskeleton. That part of the skeleton which is derived from the skin. 

 exteroceptive. Receptive to external stimuli. 

 extirpation. The complete removal of a part. 



extravasation. The escape of blood from a vessel into surrounding tissues. 

 extremity. A limb. 

 extrinsic. Originating outside an organ. 



falciform ligament. A fold of peritoneum between liver and diaphragm. 

 Fallopian tube. The uterine tube or anterior portion of Muellerian duct. 

 falx cerebri. That portion of the dura mater between the hemispheres. 

 fasciculate layer. The middle layer of the suprarenal cortex. 



