GLOSSARY. 185 



Sphyg'moscope* (Gr. spliugmos, the pulse ; skopeo, I look into). 



An instrument for indicating by means of a flame, 



variations in arterial pressure. 

 Staircase beats. A peculiar feature in heart-beats in which a 



succeeding beat is higher than the preceding; due to 



summation of impulses during artificial stimulation. 

 Stannius, Experiment of. The application of a ligature to 



frog's heart at sino-auricular junction. 

 Steap'sin. A ferment of pancreatic juice which is concerned 



in saponification. 

 Stepha'nion (Gr. Stephanos, a crown). A point of skull where 



coronal suture crosses temporal line. 

 Summation of stimuli. Occurs when a single weak stimulus 



(which is incapable of producing contraction) may, if 



repeated sufficiently often, excite the muscle. 

 Supplemental air. The air which can by a special effort be 



expelled from lungs after tidal air has lelt. Also called 



" Reserve air." 

 Supra-condyloid foramen. A bony tunnel, situated above 



internal condyle of humerus ; transmits median nerve and 



brachial artery. 

 Suspe"sory ligament. Connects odontoid process of axis 



with basi-occipital bone. Represents vestige of notochord. 



(Rathke.) 

 Synerget'ic muscles (Gr. mn, together; ergon, work). Are 



those which together subserve a certain kind of move 



ment. 

 Syn'thesis (Gr. suntithemi, to place together). The formation 



of a compound substance from simpler matter, or from 



distinct elements. 

 Syn'tonin(Gr. sun, together; teino,\ stretch). Acid albumen, 



a stage in the conversion of proteid into peptone by 



gastric juice. 



Telolem'ma (L. tela, a web ; lemma, bark of plants). The 



sheath of a motor end plate, divided into epilemma and 



endolemma. 

 Tenon, Capsule of. A thin membrane covering the posterior 



and greater portion of eye-ball. 

 Tet'anus (Gr. teino, I stretch). The fusion of a series of 



simple spasms into one apparently continuous contraction. 





