594 INFLUENCE OF RESPIRATION ON THE CIRCULATION OF THE BLOOD. 
one-tenth of arterial pressure. The breaks indicate synchronical points in the two 
tracings. 
Plate XXIII. tigs. 1, 2, 3, 4 & 5. Varieties of natural breathing: fig. 6 represents 
that form of breathing in which expiration commences with a prolonged whine. 
Plate XXIV. figs. 1-4. Obstructed respiration: figs. 1, 2 & 3, partial closure of 
breathing-tube, the degree of obstruction being indicated by the shaded portions of the 
circles B, C, D ; fig. 4, complete closure. 
Plate XXIV. figs. 5 & 6, and Plate XXV. figs. 1, 2, & 4. Artificial respiration 
after subcutaneous injection of woorara: fig. 3, period during which artificial respiration 
was arrested; figs. 5 & 6, effects of single injections of air into the chest after several 
minutes’ discontinuance of artificial respiration. 
