THE SPINAL ANIMAL 
43 
motor organ, and impel the motions of the individual. That deeper depression shows how, as the 
individual ascends the scale of being, the more percipient, the more cognisant does it become ot 
the circumambient universe outside that is 'not me;' and thus the latter acquires a more and more 
preponderant directive influence over those reflections, those expressions of the creature's neural 
states, its 'doings.' 
DESCRIPTION OF PLATES 
Illustrating The Spinal Animal (Charles S. Sherrington, M.A., M.D., F.R.S.) 
Plate I 
Fig. I. — This figure indicates the position of the limits of the skin-fields of the cervical and 
brachial spinal nerve-roots. Both the anterior and the posterior borders of the fields are indicated in 
the diagram, which renders the figure somewhat confusing. A portion of the limit ot each field is, 
however, omitted, namely, that portion of it which joins the portions of the adjacent fields to form the 
vetitral axial line of the limb. This combined portion of the borders forming the ventral axial line ot 
the limb is represented by itself in fig. 2 of this same Plate I. The lines which in fig. i indicate the 
posterior limits of the fields are finely dotted lines, thus ; the lines which indicate the anterior 
limits of the fields are simply broken thus . The number attached to each line signifies the number 
of the cervical or thoracic nerve-root in the enumeration of the vertebral series; thus 4 signifies the 
position of the anterior limit of the skin-field belonging to the fourth cervical nerve-root, and 1 . . . . 
signifies the position of the posterior limit of the skin-field belonging to the first thoracic nerve root. 
The line v signifies the posterior border of skin-field of the cranial fifth nerve. 
Fig. 2 shows the position of the ventral axial line of the brachial limb, v. a. l., as formed by the con- 
junction along the place indicated of the borders of the consecutive skin-fields of the brachial nerve- 
roots. 
Figs. 3 and 4. — These figures indicate in the same way as the preceding the positions ot the 
limits of the skin-fields of the cervical and brachial nerve-roots, and how from those limits an axial line of 
the limb is revealed by their conjunction along a certain line. These figures ditler from the two preceding 
only in giving the dorsal aspect of the limb instead of the ventral, d. a. l., the dorsal axial line. In 
fig. 3 the line v signifies the posterior limit of the fifth cranial nerve. 
Plate II 
Fig. I. — B. p. = the carotid blood-pressure in a cat (chloroform and ether, in addition to morphia 
and curare). An injection of 2^ cubic centimetres of normal saline solution at body temperature was made 
into the common bile-duct at the place marked by the signal. A marked rise of the carotid pressure 
ensued. The time is marked in seconds. 
Fig. 2. — B. p. = blood-pressure tracing from the carotid artery of the cat. s. Electric signal. 
T. Time marked in seconds. From 1 to o on the signal trace 1 cubic centimetre of normal saline solution 
at body temperature was introduced from a reservoir into the left ureter, about five seconds. The animal 
was chemically narcotized with a mixture of chloroform and ether, and by a hypodermic injection ot 
morphia; it was paralyzed with curare. Tracing reads from left to right. 
Fig. 3. — B. p. Graphic record of the arterial blood-pressure of a dog (carotid artery) under chloro- 
form and ether after morphia, and in addition to curare. The spinal cord had been completely severed 
transversely at the seventh cervical segment eight weeks prior to the observation. The gap in the signal 
trace shows when, for five seconds, the toes of one hind foot were forcibly extended. The movement 
caused a reflex rise in the arterial blood-pressure, followed by a temporary fall. Zero of b.p. marked the 
level of the float in the manometer under atmospheric pressure. It is noteworthy that there is acceleration 
of pulse as well as rise ot the arterial pressure. 
