258 



NATURE 



[Jan. i8, 1877 



animal must belong to a much larger and quite distinct 

 species, of which we trust it will not be long before 

 perfect examples are received in Europe. 



The significance of the discovery of a species of Tachy- 

 ^lossHS in New Guinea will be appreciated when we con- 

 sider that hitherto the Monotremes or Ornithodelphs, 

 which, according to the most recent authorities, constitute 

 not merely a distinct order, but even a separate sub-class 

 of mammals, have been supposed to be at present ex- 

 clusively restricted to Australia. The two only known 

 genera of Monotremes are Tachyglossus (sive Echidna) 

 and Ornithorhynchus. Of the latter the single known 

 species is peculiar to South-Eastern Australia, of the 

 former, the two species are found, one in South-Eastern 

 Australia, and the other in Tasmania, The whole of the 

 north and west of the Australian continent is, so far as 

 we are at present informed, without any representative of 

 this remarkable group. Looking at these facts, the dis- 

 covery of a species of Monotreme in New Guinea becomes 

 still more significant, and leads us to expect that when 

 the mountain-ranges of Queensland have been further 

 explored, some representative of the order may still be 

 found lingering in this district, and uniting the newly- 

 discovered area of distribution with that previously 

 known. 



Finally we may remark that the fundamental unity of 

 the Papuan and Australian fauna was already sufficiently 

 obvious by the existence amongst mammals of Macropus 

 and amongst birds of such peculiar genera as Orthonyx 

 and Clbnacieris in New Guinea. The discovery of 

 Tachyglossus bruijmi is another confirmation of the 

 correctness of this view, as regards zoology, though, as 

 regards the flora of New Guinea, facts, we believe, point 

 rathtr in another direction. P. L. S. 



ON THE TROPICAL FORESTS 

 HAMPSHIRE 1 



II. 



OF 



T T has been mentioned that in some of the clays remains 

 ■*■ of leaves, fruits, and flowers are met with, and I will 

 now proceed to tell you something about them. There are 

 some enlarged drawings here on the wall which I should 

 tell you are not all enlarged to equal scale, and there are 

 trays of specimens on the table. 



These leaves are found in various conditions of preser- 

 vation. In most cases the impression only of the leaves 

 in the clay is met wiih, but in some cases they are so well 

 preserved that the actual substance has been retained 

 although chemical changes have altered its composition, 

 and it will peel off and blow away. In some of the clays 

 the masses of leaves are so decayed that they cannot be 

 recognised, and are not worth our collecting. 



Where the preservation is good we can readily distin- 

 tinguish the various original textures of the leaves by 

 comparing their general aspect and colour both among 

 themselves and with existing forms. For instance, those 

 which are thick, such as evergreens, thin, as convolvulus, 

 hard, such as oak, or soft, such as lilac, or even velvety, 

 such as the common phlox, can all be recognised. Their 

 colours, in most of the beds, vary from bufl" to brown, but 

 I need hardly tell you that in no case have we any of the 

 green colouring of the leaves preserved. Whilst these 

 various shades of dark buffs and browns are in many 

 cases the result of chemical change that has taken place 

 after the leaf was covered up, yet I believe that in many 

 cases this change had occurred, at least partially, before 

 the covering up, just as we saw a few weeks ago the 

 changed colours of the fallen leaves of autumn. 



In the darker clays the remains are black and com- 



I Lecture in connection with ihe Loan Collection of Scientific Apparatus 

 given at the South Kensington Museum, December 2, 1876, by J. Starkie 

 Gardner, F.G.S. Continued from p. 233. 



pletely carbonised ; where this is so the finer venation is 

 indistinct and the remains difficult to save, so that we may 

 discard them unless the outline of the leaf is of unusual 

 form. The darker browns, I take it, indicate hard and 

 evergreen leaves ; for instance, the laurtl-like leaves are 

 always of a deep colour, whiht both the thin and the 

 succulent leaves are always of light colour, as in the 

 leaves which we suppose to be fig, some species of 

 smilax, &c. 



No other colours have been met with with one remark- 

 able exception ; fragments of a reed-hke aspect are found 

 of a deep violet, staining the surrounding clay mauve for 

 a considerable distance. 



Fig. 4 —Leaves op Dicotyledons, from the Lower Bagshot Beds. 



I and 2, Fagus ; 3, Laurus ; 4, Acer ; 5, Atalia (?) ; 6, Stenocarpus ; 



7, Dryandra; 8, Quercus. 



I next call attention to the shapes of these leaves ; the 

 most cursory examination shows that the differences in 

 shape are very great. Here are drawings of palmate 

 leaves, leaves resembling in general shape the beech, the 

 sub-tropical Dryandra, which, though unfamiliar, have 

 been probably seen by most of you in the warmed houses 

 at Kew ; laurel-like leaves, a tropical kind of oak, maple, 

 smilax, aralia, yew, palms, and a fern. These have been 

 selected to show the great diversity in the shapes which 

 existed. 



Most people are familiar with the process of skeleton- 

 ising leaves — that is, the removal of the green part, and 

 the preservation of what is called the skeleton. I have 

 here a large case of leaves so prepared by Mrs. J. E.i 

 Gardner, and which may be examined at the close of the.| 

 lecture, 



I would next draw attention to some leaves of trees which^ 

 are well known as now growing in England. In these a 

 continuation of the leaf-stalk can clearly be distinguished 

 running through the leaf, which is commonly called the 

 mid-rib. [The mid-ribs in two diagrams were co'oured 

 red.] Those running from the primary ribs are called 

 secondary ribs (coloured blue). There are, again, running 

 from these many smaller portions, which are calJed the 

 network of the skeleton. In some, as, for example, the 

 plane-tree, there are three primary ribs ; in a {&^ leaves 



