September 25, 1890] 



NATURE 



521 



survivor of the white rhinoceros being met with, it may 

 be carefully preserved for the National Collection at 

 South Kensington. 



As will be seen by the outline drawings of the heads,^ the 

 points by which this part of the two animals may be distin- 

 guished present themselves very appreciably. In the first 



Fig. I. — Head of Rhinoceros simus. 



place, as is already well known, the " white " or " square- 

 mouthed " rhinoceros (as it is much better called) is distin- 

 guished by its short upper lip. In R. bicornis the central 

 portion of the upper lip is far extended, and forms a quasi- 

 prehensile organ. This is sufficiently manifest in the draw- 

 ing, but may be still better seen in the living example of 

 the same animal now in the Zoological Society's Gardens. 



Head of ^. bicornis. 



A second point in which the heads of the two African 

 rhinoceroses differ materially is in the size and shape of 

 the ears. In R. dicornis (Fig. 2) the ear-conch is much 

 rounded at its extremity, and edged by a fringe of short 

 black hairs which spring from the margin. In R. simus 

 (Fig. 1) the ear-conch is much more elongated and sharply 



' Reduced from P.Z.S., 1886, PI. xvi. 



NO. IO9I, VOL. 42] 



pointed at its upper extremity, where the hairs which 

 clothe its margin constitute a slight tuft. While the 

 upper portion of the ear-conch is much more expanded 

 in R. simus (than in R. bicornis), in the lower portion 

 the two margins are united together for a much greater 

 extent, and form a closed cylinder which rises about 

 3 inches above the base. 



A third point in which the two species appear to differ 

 is in the shape of the nostrils, which in R. sitnus are 

 elongated in a direction parallel with the mouth, while in 

 R. bicornis they are more nearly of a circular shape. 

 Again, the eye in R. simus appears to be placed further 

 back in the head than in R. bicornis. 



In conclusion, I wish to call special attention to what 

 Mr. Selous has already said — that no museum in Europe 

 or America possesses a specimen of this huge animal, 

 and to point out that the country, in which alone (as is 

 possible but by no means certain) the last stragglers 

 exist, being now within the British Empire, "it is clearly 

 our duty to endeavour to obtain and preserve examples 

 of the great white or square-mouthed rhinoceros for the 

 use and information of posterity. 



P. L. SCLATER. 



RECENT RESEARCH AMONG FOSSIL PLANTS. 



A N instructive resumd of recent work among fossil 

 ■^*- plants is given by the Marquis de Saporta in the 

 Revue ght^rale de Botanique, vol. ii., 1890. It appears 

 that mosses were almost certainly represented in the 

 Palaeozoics, a species allied to Polytrichum having been 

 discovered at Commentry, in France. Rarely as the 

 fructification of ferns is preserved in the Coal-measures, 

 twenty species are now investigated, confirming the view 

 that the Palaeozoic species differed widely from the pre- 

 sent. Half of them are most nearly related to the Marat- 

 tiaceas, whilst others show affinities with the Osmundaceae, 

 Gleicheniacese, and Hymenophyllum, the vast order of 

 Polypodiaceas, and the Cyatheae being unrepresented. 

 Among the most striking discoveries in the Coal-mea- 

 sures is a fern trunk several yards in length, with its 

 fronds attached. The view that the Calamarias were 

 in part Gymnosperms is all but universally abandoned, 

 and the close affinity of the Lepidodendrons and Sigillarias 

 and their cryptogamic nature everywhere admitted, so 

 that a long controversy is ended, and the truth of Prof. 

 Williamson's contentions definitely established. Links 

 in the chain of evolution between Cryptogams and Gymno- 

 sperms still elude our search, and the earliest vegetation 

 of which we have any complete knowledge already presents 

 well-developed Gymnosperms in the shape of the deci- 

 duous Cordaites, a few Cycads and obscure Taxads 

 allied to Ginkgo. At the same time, we get rid of the 

 very puzzling Spirangium, so often regarded as a possible 

 Palaeozoic Angiosperm, but now relegated by MM. 

 Renault and Zeiller to the animal kingdom as the tgg 

 of some member of the shark family. 



Under the apparently totally dissimilar climatic con- 

 ditions of the Mesozoic, the overgrown luxuriant vegeta- 

 tion of the coal period is replaced by forests of dry 

 scale-leaved Coniferas, with undergrowths of small-leaved 

 ferns and Cycads. Fructification shows the presence of 

 Cycadea2 in the infra-Lias, and Polypodieas in the mid- 

 Jurassic. The researches of Count Solms into the 

 organization of the obscure and extinct Cycad Bennettites, 

 bid fair to clear up another important and hitherto in- 

 soluble problem — the true botanical position of William- 

 son ia. Work in the past year or so has been destructive 

 to a great deal of even recent literature on the geological 

 history of plant evolution, the foundations of all specula- 

 tive writing on this subject having as yet proved most 

 treacherous sand. 



The first appearance of Dicotyledons, once supposed 



