For the Vegetable Kingdom it is impossible to give any list composed with the same degree of elaboration as has been attained in the classification of animals. Modern plants are, it is true, as well known and as correctly grouped as modern animal life-forms; but our knowledge of fossil botany is not at all equal to our knowledge of fossil animals. The most minute divisions as well as the most important of botanical classifications are dependent upon the more fully developed and most perishable parts of vegetable organisms—the flowers and the fruits or seeds. Of these the former, the most essential of all, have rarely indeed, if ever, been preserved. One or two doubtful instances have been stated; but these have been by others disputed as being only incipient buds or leaflets, or as accidental appearances, and the investigator of the extinct forms of the vegetable creations of past geological ages has, at the best, to infer from the remains of leaves, branches, or stems, usually more or less decayed, the probable class to which the originals—often, indeed generally, of very different structures and organic characters from his existing types—belong. Not uncommonly, indeed, his only guides are vague and indefinite resemblances of form. Still, however, if it be essential for the attainment of a knowledge of the exact concatenation of past events in the succession of organic life on our planet, it is equally as important to note whether plants have been progressive in their development, as to determine this point in relation to the animal-kingdom.

These veins penetrate the crystalline schists, particularly the gneiss, in those localities where the latter are largely penetrated by porphyry. They also generally penetrate the porphyry; only a few exceptions from this rule serving to show that the porphyry-eruptions continued into the period of the formation of the ore-veins. These veins form three or four principal groups, according to their direction, which groups in general differ both in age and in contents. Still, all veins by no means show similar directions in connection with similar contents, or the converse, only these predominant characteristics often coincide. Veins of distinctive contents are almost as much confined to certain localities as they are characteristic of definite directions. According to the contents we can distinguish three or four paragenetic combinations of different ages, but which often extend into one another in such a manner that one fissure sometimes contains the products of two or three of these different periods.