iiS 



NA 2-URh 



[iMay 30, 1895 



minute living Aibalia, and that these early forms may have 

 Ijiven rise to, and have been the forenmners of, the modern 

 Nlalacostraca. ' In A'lbalia,' says Claus, ' we probably have 

 to do with an offshoot of the phyllopod-like ancestors of the 

 iMalacii>traca, which has |>ersiste<l on to the present time.' 



" The genus Esthtria existed in the fresh and brackish waters 

 of the Devonian Perio<l, in Livonia, Caithness, and Orkney, and 

 also in No\'a Scotia and Scotland. It flourished in the 

 European area at several of the Upper Carboniferous stages, and 

 was well represented in the Secondar)- and Tertiary rocks ; it is 

 also living, and has a world-wide distribution. 



" The I'hyllocarida seem in some cases to afford examples of 

 |>ersistency of tyjie, and in others of local or temporary S[>eciali- 

 saiion. fine of the oldest known is the Cambrian Hymcuoiaris, 

 a prototype of the recent Nebalia. Caryoiaris of the Arenig 

 series possibly belongs to the same group ; and the Upper 

 Silurian Ceratician's carries the form to a high degree of \ 

 perfection ; but until we meet with the Nehaiia of to-day w e 

 have no tangible links in this series in intermediate geological 

 limes. Walcott's Cambrian Protocaris is quite susceptible of 

 being regarded as a predecessor of the living Aptis. The 

 Carlxmifcrous Dithyrocaris and its allies stan<l probably in the 

 relation of genealogical links. But much more research among 

 these interesting lower crustacean fossils is required before their 

 phylogenetic relationship can lie fully elucidated. 



"The Ostracoda, which have the entire body enclosed in a 

 shell or carapace composed of two valves united along the back 

 by a membrane (represented by such forms as Cyfris, Cypridiim, 

 Caitdona, Beyruhia, Primitia, &c. ), are chiefly dwellers in 

 shallows, and occur both in fresh and salt water ; they are 

 usually of minute size ; but there are deep-sea ty]ies which 

 attain comparatively large dimensions (an inch long). They are 

 met with in rocks of almost all ages from the Cambrian up- 

 wards. To speak of them here is to recall the nearly life-long 

 labjurs (from almut 1840) devoted to their elucidation by I'rof. 

 T. Ru|XTt Jones, who has described many hundreils of these 

 primitive Crustacea from rocks of every British formation as 

 well as from very many foreign countries. 



" Cireat as are the transformations which these organisms have 

 witnessetl in the long cycles of geological change from Lower 

 Cambrian to modern time, they present, nevertheless, a general 

 iacies, and (like the genus Uiii;ii!a amongst the brachiopoda) 

 must lie looked upon as one of those persistent types which 

 lK»s.sess enormous power of multiplication, so that entire beds of 

 rock may !« .said to \te com[)osed of their microscopic tests. 

 The linng species also |X)sscss»;xceptional powers of endurance 

 and provision for the preservation of their lives in periods of 

 drought, often retaining their vitality in a dormant stale perhaps 

 for years : thus they have persi.stcd through all the vicissitudes 

 of geological time, representeil by the entire succession of the 

 Mratitied nxks ; ' all things changing, but themselves un- 

 changed.' 



" None of the older Ostracoil genera exist now ; but .some of 

 the existing forms of the Cypridi<l;e, Cytherid.T;, and CytherellidiC 

 are fully represented by predecessors in the I'alxo/oic rocks. 

 The wonderfully well-preserved Pa/,eo,ypris Edu'ardsii, dis- 

 covered by Dr. C. Hrongniarl, enclosed in transparent silica, 

 •lisplaying the soft parts of the .inimal as perfect as in life, from 

 the Coal Measures of Si. Elienne, is evidence of the existence 

 of Cyprids in that far-off time. 



" I have endeavoured to depict in a diagram (p. 115) the evolu- 

 tion of the Arthroptjda in geological lime. 



" In conclmling this brief excursion over the abysses of 

 I'ak-ezoic lime, I have only Iwen able to bring under your 

 notice a few isolated points of interest in the crust.icean fauna 

 which lie in the depths of these ancient (lc|Kisils. They may, 

 however, serve to show that this group of lowly existences is 

 not destitute of interest for the biologist. There may also be a 

 (Hissibility of connecting these isolated observations .so a.s to 

 »how their hearing upon the greater question of the development 

 of life. 



" In order, however, to do this effectively I must ask you to 

 accomjKiny me next year in a sec^ind excursi^pn over the newer 

 I'al.-eotrjic and Kaino/oic seas, where, nearer land and in shallower 

 waters, wc shall find a still greater variety of life-forms to study. 



"Two conclusions may lie drawn from our fibservations, namely, 

 (I) that the ancient faunas of the earth were far more wide- 

 »prcad, more simple and more uniform than are our recent faunas ; 

 and (2) if, a.t (he researches of geologists seem to indicate, other 

 Mdimcntary rocks exist, nldrr than the Lower Cambrian, then 



NO. 1335, VOL 52] 



we may hope to gather evidence of still earlier and more simple 

 forms of life than are met with in the ' O/ou/.'m-zonc' We are 

 fully justified in concluding that such must actually have 

 existed, because we find in the Lower Cambrian evidence of a 

 quite considerable fauna belonging to several divisions which, 

 although lowly in themselves, are nevertheless already so clearly 

 (lifferentiate<l one from the other as to prove to us that we are 

 still, lx)th biologically and chronologically, very far removed 

 from the commencement of life on the earth." 



SCIENTIFIC SERIALS. 



American fouriia! of Siience, May. — On the colour relations 

 of atoms, ions, and molecules, by M . Carey Lea. Part i . The 

 colour or absence of colour of an element is a fimction of its 

 atomic weight. No element having ions coloured at all valencies 

 can belong to the same natural group with elements having 

 colourless ions only. The entire class of elements with colour- 

 less ions is divi<led into nine great natural groups, as follows : — 

 II, K, CI. Br, I : Li, Na. K, Kb, Cs : Ca, Sr, Ba : Sc, Y, La ; 

 Be, .Mg, Zn, Cd, Hg ; B, .U, Ga, In; C, Si, Ge, Sn, Pb, 

 Th ; N, P, As, Sb ; O, S, Se, Te. This first great division of 

 the elements includes all those whose ions function .is anions, 

 anil also part of the cathion.s. Intermediate between the two 

 chief divisions are eleven transitional elements, viz. Ti, V, Cu, 

 Nb, Mo, Ag, Ce, Ta, \V, Th, Bi. These have ions which at 

 some valencies are coloured and at others colourless. These are 

 cathions only. With atomic weights ranging from I to 47 the 

 atoms are colourless ; 52 to 59 coloured ; 65 to 90 colourless ; 

 103 to 106 coloured : 112 to ijgcohmrless ; 145 to 169 coloured ; 

 192 to 196 coloured. Elements whose place in the numerical 

 series falls between these periods have both coloured and colour- 

 less atoms. The six heaviest metals .at the end of the series are 

 allern.-itely coloured and colourless. — .4rgon, l'rout"s hypothesis, 

 and the periodic law, by Edwin A. Hill. \ very interesting 

 question connected with the discovery of argon is what will be 

 the effect of these researches upon Prout's hypothesis? It is 

 possible that argon has lieen an unsusiiected cause of error, 

 which, when properly allowed for, will show the ratio of H to 

 O to be almost exactly I to 16. This would make so many 

 atomic weights even or half multiples of 11 as to render probable 

 the generation of the elements from a common form of matter 

 by the continued addition of some one or more constant in- 

 crements of mass. — Relation of the plane of Jupiter's orbit to 

 the mean pl.ine of 401 minor planet orbits, by H. .\. Newlon. 

 The secular perturbation of the orbit of a minor planet by Ju]iiter 

 is such that the inclination of the orbit plane is not greatly 

 changed, but the node has a constant motion. Whatever may 

 be the distribution of the poles of these orbits at one epoch, ihe 

 tendency of the secular perturbation by Jupiter is to finally dis- 

 tribute them symmetrically around the pole of Jupiter's plane. 

 The present inclin.ition of the mean plane to Jujiiter's ]ilane 

 iiO°-43. 



American Mclcorohsical Journal, May.— The cause of cy- 

 clones, by Prof. .\. Woeikof The article deals chiefly with two 

 points mentioned in a former paper on this subject by Mr. 

 Dines. Dr. Woeikof considers that the balloon ascent from 

 Munich on December II, 1890, showed that, while there is no 

 cooling of the free air in calm anticyclonic weather, the radia- 

 tion of the surface of the snow cihiIs the surrounding air, even 

 on an isolateil mountain. With regard to the suggestion that 

 the latent heat set free by condensation is sufficient to cause a 

 storm, he points <mt that the heat set free by copious condensa- 

 tion in India does not produce storms. — Meteorological problems 

 for physical laboratories, by Prof. C. Abbe. Kew physical 

 laboratories have conveniences for studying .lero-dynamics, but 

 Ihe author, with the assistance of Prof C. K. Marvin, gives a 

 list of Ihirty-seven sulijecis for experimental investig;ilion which 

 demand allention from meteorological stuilents. - Long range 

 weather forecasts, by Prof H. A. Hazen. The author jivils for- 

 ward a scries of crucial tests of we.ather forecasts, more particu- 

 larly with Ihe view of showing Ihe fallacy of the precbrlions 

 based on the positions tif the mmm, planets, \c. — There is also 

 an article by !•'. B. While on to|iographic influence on the winds 

 of the weather maps, which frequently show erratic winds, 

 having no dependence on the l.io.nM-rir gr.ulienls cliar'.ed with 

 them. 



