GLOSSARY 675 



gastrula. The two-layered stage of ontogenesis. 



gelatin. The translucent protein which forms jelly and glue. 



genetic. Pertaining to origin or birth. 



geniculate body. A tubercle-like body in the lower part of the optic thalamus. 



geniculate ganglion. The ganglion of the facial nerve. 



genital. Pertaining to the organs of reproduction. 



gestation. Pregnancy. The condition of being with child. 



gigantism. Excessive growth sometimes due to disease of the anterior lobe of the 



pituitary. 

 gingiva. The gum. The tissue which covers the jaw and surrounds the necks of the 



teeth. 

 gizzard. The muscular grinding stomach of birds and reptiles. 

 gladiolus. The middle chief portion of the sternum. 

 glans penis. The swollen terminal portion of the penis. 

 glenoid. The concave depression in the scapula in which the head of the humerus 



articulates. 

 globus pallidas. The pale interior of the lenticular nucleus of the corpus striatum. 

 glomerulus. The knot of capillaries of a renal corpuscle, 

 glottis. The pharyngeal opening of the larynx. 



glycogen. Animal starch, a carbohydrate stored in the liver and other tissues. 

 gnathostomes. Fishes with biting jaws in contrast with cyclostomes. 

 goblet-cells. Mucus-secreting cells of the intestine. 

 goiter. Enlarged thyroid gland. 



Golgi-Mazzoni corpuscles. Special tactile corpuscles of the finger-tips. 

 gonad. A gamete-producing gland. 



gonotome. That part of the mesoderm which forms the gonad or germ-gland. 

 goose flesh. The formation of skin papillae due to the action of cutaneous muscles on 



hairs. 

 Graafian follicle. An ovarian vesicular sac containing an ovum and secreting an 



hormone (estrin). 

 Grandry's corpuscles. Special tactile corpuscles of tongue and mouth. The same as 



Merkel's corpuscles. 

 granulocyte. A leucocyte which contains coarse granules. 

 gray matter. That portion, mostly cellular, of the central nervous system which lacks 



the white myelin. 

 groin. The part of the abdominal wall adjacent to the thigh. 

 gubemaculum testis. The fetal cord which attaches the testis to the scrotal sac. 

 gullet. The esophagus. 

 gustatory. Pertaining to the sense of taste. 



gynandromorph. An organism having both male and female characteristics. 

 gyrus. A fold or convolution of the brain cortex. 



hagfish. The cyclostome myxine. 



habenular commissure. The "superior" commissure which connects the habenular 



ganglia in the roof of the diencephalon. 

 habenular ganglia. Olfactory centers anterior to the pineal body. 

 hamate. The distal carpal bone adjacent to the fifth metacarpal. 

 haploid. The reduced number of chromosomes found in mature germ-cells. 

 harelip. A congenital cleft in the upper lip, rarely double. 

 Harrimania. A genus of hemichordates. 

 harvest men. Long-legged spiders or "daddy-long-legs." 

 Hassall's corpuscles. Clusters of concentrically arranged epithelial cells of the thymus. 



