134 



NA TURE 



[December 7, 1905 



lampreys. The organisation of the " bear-animalcules," or 

 Tardigrada, those microscopic creatures found in damp 

 moss and the gutters of roofs, forms the subject oi an 

 article by Mr. A. Basse ; while the third and last com- 

 munication is the first portion of a memoir by Mr. S. 

 Hlava on the Radiata, the author dealing in this instance 

 with the anatomy of Conochiloides natans. 



In an important article on the cranial nerve-components 

 of the lamprey (Petromyzon), published in Gegenbaur's 

 Morphologisches Jahrbuch, vol. xxxiw, part ii., Mr. J. B. 

 Johnston shows that the general arrangement is similar 

 to what obtains in fishes, although with certain markedly 

 primitive features. As the result of a study of the visual 

 organs of the ;im idians of the Salpa group, Mr. W. 

 Redikorzen arrives at the conclusion that the primitive 

 chordates possessed a series of paired organs of this nature 

 extending from the head to the tail — one pair to each body- 

 segment. Moreover, the pineal eye was certainly in the 

 first instance a dual structure, but later its two elements 

 coalesced and subsequently degenerated. This segmental 

 ocular type has entirely disappeared from vertebrates, and 

 is now represented onlj by traces among the lower groups. 

 The other papers in the same issue include- one by Mr. T. 

 Mollison on the dorsal gland of Dendrohyrax, and a second 

 by Mr. J. Bohm on the reproductive organs of the sheep. 



In the November issue- of the /'-,./,, ,_- M / Mr. G. Renshaw 

 resumes his interesting series of " obituaries " of extermin- 

 ated animals, dealing in this instance with the Reunion 

 starling, the sole representative of the genus Fregilupus. 

 Easily recognised b) its parti-coloured plumage and long 

 crest, this bird was probably discovered Icy Flacourt in the 

 middle ■■■! the seventeenth century. In the early part of 

 the- lasi century it was abundant, but in 1833 had become 

 extremely scarce, and by about i860 had probably ceased 

 to exist even in its last refuge in the interior of the island. 

 Twenty-one skins, of which one is in the Natural 1 listen 

 Museum (although not shown to the public), and two 

 skeletons, of which om- is at Cambridge, are all the relics 

 of this interesting sp,-< i.-s Mr. Renshaw can identify. In 

 another paper Dr. J. Mini- discusses the flying-fish cap- 

 tured in September last in .1 back-water connected with 

 the Medway estuary. It is believed to belong to Exocoi tus 



lineatus, .1 speci previously recorded as an occasional 



straggler into British waters. 



The almecst complete shell of a large Cretaceous turtle 

 from Kansas has afforded Mr. t .. R. Wieland the oppor- 

 tunity of enlarging our knowledge of the extinct genus 

 Toxochelys, his communication on the subject being pub- 

 lished in the November issue of the- American Journal of 

 Science-. The structure- 0! lie shell agrees with that 

 of certain extinct representatives of the Chelonida? 

 (Lytoloma), but the- skull approximates to that of the 

 Chelydridae. That the genus should lee- dassed with the 

 true turtles the author is convinced, although he believes 

 the limbs to have been independently modified for 

 swimming. The most interesting part of the paper relates, 

 however, to certain bony elements overlying the junctions 

 between the neural bones of the- carapace, and it is sug- 

 gested that these-, which max have l>e-e-n more extended in 

 other types, may represent the- mosaic-like shell of the 

 leathery turtles (Dermochelyidae). If this suggestion be 

 well founded, the- puzzle of the origin of the carapace of 

 Dermochelys will be practically solved. 



The Comptes rendus of the zoological congress held at 

 Berne last year contains the full re-port of a series e,l 

 experiments undertaken by Mr. 11. PieVon with the view of 

 ascertaining the seat of the recognition-sense among ants. 



NO. 1884, VOL. JT,] 



The theory ol a " language-sense " resident in the antenna 

 is rejected by the author, to some extent on the ground 

 that these organs are employed in feeling objects ol everj 

 kind, animate and inanimate. On the other hand, it is 

 inferred that these- organs are endowed with an olfactory 

 sense, ,,n which depends mutual recognition among tints. 

 As is well known, ants not only of different spe-. ies, bm 

 of different communities of the same species, display 

 marked hostility to one another. By making an infusion 

 .el ants of one particular community, and anointing the 

 neuters 'if another community with this infusion, it was 

 found that in most instances the hostile ants thus treated 

 w.-re- not attacked by the members of the community from 

 which the- infusion was made, this immunity from attack 

 lasting only so long as the influence of the infusion per- 

 sisted, On this and other experiments of a kindred nature 

 ih.- author's conclusions are mainly based. But to connect 

 ihe-se- experiments with the antennae, an ant was deprived 

 . I thos,- appendages, when it was found to attack friends 

 and foes alike. Mr. Pieron has also favoured us with a 

 copy of another paper, from the Bulletin de I'Institut 

 psychologique for 1904, on the role of the muscular sense 

 in determining orientation among ants. 



I 111 experimental station at Peradeniya, Ceylon, has 

 rapidly grown into public favour, and large numbers "I 

 agriculturists visit tin- station to get practical le-ss,,ns in 

 their craft. From the annual report of the controller, Mr. 

 II. Wright, published as vol. iii.. No. 10, of the Circulars 

 of the- Royal Botanic Gardens, it will be seen thai .1 < < • 1 1 - 

 siderable amount of time has been devoted to the subject 

 of green manures. While the first object consists in grow- 

 ing 1 crop to turn into the soil, the additional advantage 

 possessed by leguminous plants of fixing free nitrogen has 

 led to their almost exclusive use-. In a tropical country 

 green manures also prevent erosion of the soil bj heavj 

 rain tend the baking of the surface by the hot sun. C rota- 

 toria striata is strongly recommended for tea estates, since 

 it produces a heavy crop. A plant of a different kind is 

 th.- thornless dadaps, Erythrina lithospcrma, from which 

 cuttings five feet long planted in tin- rain} season ^.cve- 

 a substantial yield. The Pondicherry variety ol ground 

 nut has also proved useful. 



J\ 1 lie- report of the director of the Mineralogical Survey 

 contained in the Ceylon Administration Reports much 

 valuable information is given by Mr. A. K. Coomaraswamy 

 and Mr. James Parsons regarding the occurrence of 

 corundum, of minerals containing rare earths, of precious 

 stones, of crystalline limestone, of mica, and of graphite. 

 With the aid of numerous illustrations, interesting de- 

 scriptions tire also given of the native Sinhalese manu 

 facture of iron anil steel, and of the washing of gem-bearing 

 gravels. The minerals containing rare earths have been 

 derived from intrusive granite rocks. Thorianite contain- 

 ing more than 70 per cent, of thoria and 12 per cent, to 

 15 per cent, of uranium oxide occurs in moderate quantities 

 near Kondrugala. The whole amount obtained hitherto is 

 less than 30 cwt., and it is doubtful whether any very 

 extensive deposit occurs. Thorite, allanite, and minerals 

 of the samarskite group have also been found. The gems 

 met with are transparent and well coloured varieties of 

 corundum, spinel, zircon, tourmaline, topaz, garnet, chryso- 

 beryl, cordierite, amethyst, felspar, and beryl. Many of 

 1 Ins, en- exhibited in the mineral gallery of the museum 

 attached to the survey, and the director is making strenuous 

 endeavours to get together a thoroughly representative 

 collection which can always be consulted by visitors to 

 Ceylon. 



