Summary. 
In Animals. 
(1) By its tonie contraction, the trapezius or its equivalent exerts 
an important influence in converting the shoulder into a fixed point 
from which respiratory muscles can act in pronograde mammals. 
(2) It is further reinforced in this function by its being actually 
a muscle of respiration in these animals. 
(3) In case of failure of the trapezius or its equivalent to per- 
form these functions, respiratory embarrassment and ataxia of the 
forelimb result. 
In Man. 
(4) The tonic action of the trapezius holds the shoulder in 
position and relieves the chest of the weight of the arm. 
(5) Its respiratory action may become very pronounced in certain 
cases of paralysis, while it is constantly in action as a respiratory 
muscle working harmoniously with the other muscles of upper thoracic 
respiration. 
(6) Where the trapezius fails to perform these functions the 
respiratory embarrassment may not be marked, but symptoms may 
appear in the upper brachial cords as a result of mechanical injury. 
References. 
(L) Geppes. “Intense Neuralgic pain in the Arms after Child-birth.” Lancet, 
May 18th, 1912. 
(2) Bett. The Nervous System. 3rd Ed. 1844. 
(3) THorBurN and GARDNER “Case of Tumour of the Axis.” Brain. 1903. 
(4) BERNARD. Lecons sur le systeme nerveux. T. ii, 1857. 
(5) LESBRE et Maranon. “Contribution a la physiologie du pneumogastric et 
du spinal.” Annales Soc. d’ Agric. Sciences et Indus. Lyon. 1907. 
(6) Topp. “Descent of the Shoulder.” Anat. Anz. Bd. 41, 1912. 
(7) Inrp. “The Sterno- and Brachio-cephalic muscles and their nerve supply.” 
Anat. Anz. Bd. 44. 1912. 
(8) Isın. “Injuries of the nerve supply to the musculus brachio-cephalicus.” 
Anat. Anz. Bd. 41, 1912. 
