When the summits of these are worn by mastication their surfaces present circles of dentine surrounded by a border of enamel, and as attrition proceeds different patterns are produced by the union of the bases of the cusps, a trefoil form being characteristic of some species.
Organization and tactics did not affect the issue directly, for the conduct of the men and their junior officers gave abundant proof that in the hands of a competent leader the " linear " principle of delivering one shattering blow would have proved superior to that of a gradual attrition of the enemy here, as on the battlefields of the Peninsula and at Waterloo, and this in spite of other defects in the training of the Prussian infantry which simultaneously caused its defeat on the neighbouring field of Auerstadt.
There are conditions in which we have an abnormal increase in the tissue elements but which strictly should not be defined as hypertrophies, such as new-growths, abnormal enlargements of bones and organs due to syphilis, tuberculosis, osteitis deformans, acromegaly, myxoedema, &c. The enormously long teeth sometimes found in rodents also are not due to hypertrophy, as they are normally endowed with rapid growth to compensate for the constant and rapid attrition which takes place from the opposed teeth.
Should one of these teeth be destroyed the opposed one loses its natural means of attrition and becomes a remarkable, curved tusk-like elongation.
In the end complete success rewarded the sacrifices and efforts of the Federals on every theatre of war; in Virginia, where Grant was in personal control, the merciless policy of attrition wore down Lee's army until a mere remnant was left for the final surrender.
When the attrition is carried further, so that the grain is reduced to small round pellets, it is termed " pearl barley."
As the part east of the river was once covered by the ice-sheet, its hills have been lowered and its valleys filled through the attrition of glaciers until the surface has a gently undulating appearance.
The policy of "attrition" upon which Grant had embarked, and which he was carrying through regardless of his losses, was having its effect.
It shows no trace of grinding lines or attrition, nor yet of the blows of a hammer.
Hence for the indifferent Christian, Attrition, Confession and Indulgence became the three heads in the scheme of the church of the later middle ages for his salvation.
This doctrine of Attrition had not the undivided support of the theologians of the later medieval church; but it was taught by the Scotists and was naturally a favourite theme with the sellers of Indulgences.
Treating this rule as axiomatic the Schoolmen elaborated their analyses of the sacrament of penance, distinguishing form and matter, attrition and contrition, mortal and venial sins.
Yet the attrition if slow was sure, and by the end of the century the proportion of land belonging to Roman Catholics was probably not more than one-tenth of the whole.