The result of the entrance of a virulent bacterium into the tissues of an animal is not a disease with hard and fast characters, but varies greatly with circumstances.
It should be observed, however, that the repeated intercalation of marine deposits within the continental series and the frequent occurrence of thin coaly layers in the marine series makes any hard and fast distinction of this kind impossible.
It is by no means certain that a hard and fast line can be drawn between intraand intercellular lumina.
It is extremely difficult, if not impossible, to draw a hard and fast line between epistemology and other branches of philosophy.
Modern research seems to show that living protoplasm, wherever it exists, is subject to certain laws and manifests itself by certain phenomena, and that there is no hard and fast line between what prevails in the two kingdoms. So it is with the diseased conditions to which it is a prey: there is a wonderful community of design, if the term may be used in such a sense, between the diseases of animals and plants, which becomes singularly striking and instructive the more they are inquired into.
Obtaining hard and fast evidence was their not-always simple chore.
No hard and fast physical distinction can be drawn between the various classes of short-period variables; as the distance between the components diminishes the Algol variable merges insensibly into the (3 Lyrae type.
These systems are separated one from another by unconformitics in most places, and the lower systems, as a rule, have sufferetl a greater degree of metamorphism than the upper ones, though this is not to be looked upon as a hard and fast rule.