This is chiefly remarkable because of the general tardiness of change in the stamina, since it shows that the binary formation of the pistillum is a primary effect: it may be asked, if the number should be 5, why has it not reverted to its original or typical state? The calyx is not reducible to 5. The permanency of the character of aggregate flowers is here shown, as well as in Echinops, so that it is scarcely probable we shall ever meet a compositious flower solitary in the axil of an ordinary leaf.
To be examined hereafter in detail.
If wood is a descending formation, produced by leaves, how are woody tendrils to be accounted for. In the vine the ancient tendrils are perfectly woody, although this may not be true wood, yet it is truly fibrous, and I ask, from what is it formed?
The growth of young shoots is at once a proof that the whole system may be formed from ascending growth, for in many we find woody fibre complete, though not indurated, and all the leaves from which wood is said to be formed are only in a rudimentary state.
October 2nd.—Seh-Baba. Spiræa belloides, commonish on limestone rocks in the ravine near the road which leads from Tazeen valley to Khubur-i-Jubbur. This limestone is in thin strata; the strata are subdivided by quartzose veins, they occur generally at a dip of from 15 to 20 degrees, but are occasionally quite vertical or highly wavy, presenting evidence of concentrated force upwards. The outcrop wears an uniform aspect, and occurs to the north of the ravine. The south here and there presents sheets of rock, the overlying strata having slipped off. The strike of the strata is north and south.
Coal is said by Hatchet to be formed chiefly from the resinous principles of plants,—this would account for its appearance when burnt, which is the same as that of burnt bitumen. But resinous principles are, even when they exist, of partial extent only in plants. In good coal the whole of the vegetable substance seems to be transformed, a supposition barely compatible with Hatchet’s idea.
To study this, extensive examination of coal in all degrees of formation would be necessary, beginning with the wood so curiously changed by the Brahmapootra, i.e. brown coal occurring in its sand banks, and which has a very peculiar and disagreeable odour when burning. It would also be necessary to examine how far the coal-plants exhibit vegetable structure, are they mere impressions or are they the plants themselves changed? To what extent do these agree with coal? What particular plants and what parts of these appear to have formed coal? Its fibrous structure would hint at formation from the woody system, and it is not incompatible with the deliquescence of a thick layer of drift.
The plants of coal fields having been drifted, can only give us an idea of the vegetation along the natural drains of the then country, such may by no means have had one universal character.
The plants of the open surface of modern tropical countries being generally different from those along the beds of streams, in which situations now-a-days Equiseteæ, Lycopods and Filicis are chiefly found. Coal being drift, it follows that the plants of the coal fields can give us no information on the distribution of vegetables in those days; to gain information on this, the fossils should be in their original situation. And there again an obstacle may exist in our not being able to ascertain the height or level of that situation.
If the plants of coal fields are found to be converted into coal, then the only difference between coal shale, and coal will consist in the very small proportion of vegetable matter in the former.