Malformations. Excessive Development of the Nearer and Remoter Segments.—But there are other proportions that are of interest to us, within the limbs themselves. Even between the nearer and remoter portions of the limbs there ought to be certain constant relations (indices) that constitute differential characteristics between the various human races and between man and the ape. If the humerus or upper arm is taken as equal to 100, the radius or forearm is equal to 73 in the European, while in the negro it is equal to about 80. Furthermore, it is a well-known fact that excessive length of the forearm is an ape-like characteristic.

Consequently, the measurement of the segments of the limbs is important, and it is made with a special form of calipers; when the index of the segments deviates from the accepted normal figure, this constitutes a serious anomaly, frequently found in degenerates, and it often happens that an excessive development of the remoter segments, the bones of the extremities, explains the excess of the total spread of the arms over the stature, unassociated with the macroscelous type.

Absence of Calf.—In addition to this fundamental deviation from normality, there are other malformations worthy of note that may occur in the limbs. Such, for example, is a deficiency or absence of the calf of the leg. The well-turned leg, which we admire as an element of beauty is a distinctive human trait most conspicuous among the races that we regard as superior. Among the more debased negro races the leg is spindling and without any calf; furthermore, it is well known that monkeys have no calves, and still less do they exist among the lower orders of mammals.

Flat Feet.—Another important malformation relates to the morphology of the feet. Everyone knows the distinctive curve or arch of the foot, and the characteristic imprint which it consequently leaves on the ground. Sometimes, however, this arch is missing, and the sole of the foot is all on the same plane (flat foot). The dark-skinned natives of Australia have flat feet as one of their racial characteristics; in our own race it constitutes an anomaly that is frequent among degenerates. Flat feet may also be acquired as the result of certain employments (butler, door-keeper, etc.), which compel certain individuals to remain much of the time on foot. But in such cases the deformity is accompanied by a pathological condition (neuralgic symptoms and local myalgia). Like all malformations, this may have special importance in connection with infantile hygiene (the position of the pupil, the work done by the children, etc.).

Opposable Big Toe.—Another malformation combined with a functional anomaly, that is never met with as a deformity resulting from adaptation, is the opposable big toe. Sometimes the big toe is greatly developed and slightly curved toward the other toes, and capable of such movement as to give it a slight degree of opposability; hence the foot is prehensile. This characteristic, regularly present in monkeys, is so far developed in certain degenerates as to make it possible for them to perform work with their feet (knitting stockings, picking up objects, etc.); so that this class of degenerates, who are essentially parasites, solve the problem of supporting themselves by trading on the curiosity of the public, so that, by straining a point, we might bestow upon them the title of foot labourers.

Loose and Stiff Joints.—Anomalies may also occur in connection with the articulation of the joints. It sometimes happens that they are extremely loose and weak, and allow the bones an excessive play of movement; and, if the lower limbs are thus affected, it increases the difficulty of maintaining equilibrium when standing erect or walking. On the other hand, it may happen that the articulations are too stiff, and consequently render many movements difficult, especially if through an anomalous development of the outer coating of the bone, it results in congenital ankylosis.

Curvature of the Legs.—A special importance attaches to certain alterations undergone by the heads of the bones which contribute to the formation of the knee, because of the curvature of the leg which results from them (rachitis, paralysis). The leg may become bowed outward or inward; when it is bowed inward (knock-knees, genu valgum), the knees strike together in walking; when, on the contrary, it is bowed outward, the result is bow-legs (genu varum), known popularly in Italy as "legs of Hercules," a deformity which in a mild degree may also result from the practice of horse-back riding.

Club-foot (Talipes).—Other deviations from the normal position occur in connection with the foot. Certain paralytic children (Little's disease) walk on the fore part of the foot (talipes equinus, "horse's foot"); in some cases the foot is also turned inward, and consequently such children cross their legs as they walk (talipes equino-varus).

The Hand

Chiromancy and Physiognomy. The Hand in Figurative Speech. The High and Low Type of Hand.—The hand is in the highest degree a human characteristic. It is man's organ of grasp and of the sense of touch, while in animals these two functions are relegated to the mouth. The hand has always claimed the attention not only of scientists but of all mankind without distinction. Attempts have been made to discover the secrets of human personality from the hand, and a whole art has been built up, called chiromancy, which endeavours to read from the hand man's destiny and psychic personality, just as physiognomy was the art of interpreting the character from the face.