io8 



NATURE 



[Nov. 30, 1876 



In oiher words, during the hottest months the influence ol the 

 heated laud is powerfully felt, but during the other two-thirds of 

 the year the peculiar distribution of the temperature is deter- 

 mined by the strong south-westerly winds and current of 

 the Atlantic. This influence of the Atlantic on the tem- 

 perature sf Western Europe is enormous, the thermic ano- 

 maly for January being estimated by Prof. Mohn to be 

 io°-8 in the interior of Norway, 25°-2 in Scotland, 32° -4 in the 

 north-west of Iceland, while in Lofoten it amounts to 4l°"4. In i 

 May-June and in a slight degree in July-August, a large extent 

 of cold water appears as if thrust out from the Arctic Sea west 

 of Jan Mayen to the south-eastwards as far as Faro, deflecting 

 and crowding together the whole of the isothermals over this 

 region in a most remarkable manner. This is a point which 

 well deserves the most careful investigation, not merely from its 

 evident importance to the fisheries of this part of the Atlantic, 

 but also from its meteorological significance, it being in May and 

 June that atmospheric pressure reaches its annual maximum, 

 northerly and easterly winds their greatest predominance, the 

 weather becomes brightest and clearest, and the rainfall sinks to 

 its annual minimum over the extreme north-west of Europe. An 

 instructive comparison is also made between the temperature of 

 the sea and that of the air, and a valuable discussion is added of 

 the observations made at different depths of the sea between 

 Iceland and Norway ; but for these and other interesting points 

 we must refer to the papir itself. 



BIOLOGICAL NOTES 



New Fresh-water Rhizopods. — For maiiy years the small 

 group known as Actinophrys, first accurately described by 

 Ehrenberg, remained somewhat isolated, distinguished among 

 unicellular forms by its nearly constant spherical form, and the 

 persistence of its straight radiating processes or '' pseudopodia." 

 But in recent years a whole series of organisms has been de- 

 scribed, and has attained sufficient prominence to constitute, 

 with Actinophrys, an order denominated Heliozoa. Many in- 

 teresting papers have appeared in the Archiv fiir mikroskopische 

 Anatomic on these organisms, contributed by E. Hertwig, 

 Lesser, Cienkowski, Greeff', and others ; and in our own country 

 Mr. W. Archer has been the most active and successful student 

 of the Heliozoa, his papers having been priBclpally published 

 in the Quarterly Journal of Microscopical Science. From these 

 one derives an idea of these animalcules as being the most com- 

 plex of the free forms which possess pseudopodia, and are at 

 the same time unicellular ; they are neither multicellular and 

 differentiated like the Radiolatia, nor organised like the ciliated 

 Infusoria. While a few forms, as Actinophrys, are quite devoid 

 of skeleton, most of them possess certain hard parts, consisting, 

 it may be, of a tingle solid and globular piece, but in other cases 

 of very minute rod-shaped spicules, sometimes sihceous, some- 

 limes easily soluble. These are either disposed so as to invest the 

 main body of the organism more or less closely, or radially, pro- 

 jecting as spines. When food is taken, these minute hard parts 

 can be pushed aside to allow access to the central body-mass ; 

 and the same occurs when indigestible material is thrust out. 

 Locomotion is usually very slow ; most Heliozoans move by 

 balancing themselves on the tips of their pseudopodia, and thus 

 very gradually rolling onwards. Multif.'lication of the organisms 

 is effected by division, either simple, or occurring afcer encysta- 

 tion. Some forms are remarkable for containing a great abun- 

 dance of chlorophyll granules. 



Re-arrangement of the Orders of Endogens. — At a 

 recent meeting of the Linnean Society of London, Mr. Bentham 

 proposed an entirely new arrangement of the orders of Endogens, 

 which he believes to be more in accordance with their genetic 

 affinities and the essential points of their structure, than any at 



present in use. He proposes to classify Endogens under four 

 series, viz., I. Epigyn-E ; flowers with a double usually petaloid 

 perianth ; ovary usually inferior syncarpous. 2. Coronarie^e ; 

 flowers with a double usually petaloid perianth ; ovary superior, 

 almost always syncarpous. 3. Nudiflor^e ; flowers usually 

 achlamydeou?, or with a dry perianth ; ovary mostly apocar- 

 pous ; and 4. Glumai.es ; perianth replaced by membranous 

 scales (pales or lodicules) ; ovary always uniovular. The orders 

 are arranged thus in the four series : — in the firs^, Hydro- 

 charidere, Scitaminese (including Musacese, Cannaceae, &c.), 

 Orchide^E, Burmanniacese, Irideoe, Amaryllideae (including Hae- 

 modoracese), Taccacese, Dioscoridere, and Bromeliacea; (?) ; to 

 the second, Roxburghiaceas, Liliacea; (including Melanthaceae, 

 Smilaceae, &c.),PontederiaceK, Philydracete, Xyrideae, Comme- 

 lynacese, Junceaa, and Palmce ; to the third, Pandaneas, Aroidese, 

 Typhacese, Lemnacese, Naiades (including Juncagineae), and 

 Alismacesc (?) ; and to the fourth, Eriocaulepe, Centrolepidese, 

 Restiacese, Cyperacece, and Gramineas. 



The Sensation of Sound. — At a recent meeting of the 

 Vienna Academy a paper was communicated by Dr. Isidor 

 Hein "On the Relations between Perceptions of Touch and 

 of Hearing." His conclusions are these : — i. The sound pro- 

 duced by striking a solid body is always accompanied by a sen- 

 sation of touch, which, like the sound, differs according to the 

 nature of the body. If the sound is different in dift'erent parts 

 of a body, there goes along with the variation of the sound, a 

 variation in the touch-sensation ; and if the surface be divided 

 into several sections according to differences in sound, a con- 

 gruent division may be made on the basis of touch. 2. On 

 bringing a struck body towards a reflecting wall, the sound and 

 touch-perceptions show similar variations. 3. To the touch- 

 perception in question correspond vibratory motions of the 

 exterior body, produced even with the weakest sti:king, whereas 

 sound only begins to be perceived with impacts of a certain 

 intensity. 4. The sense of touch is capable of perceiving vibra- 

 tions and comparing the differences of these. It brings hereby 

 to consciousness, a special quality of touch-sensation, which is to 

 be distinguished from sensation of pressure. 5. This distinguish- 

 ing power of the organ of touch, not sufficiently appreciated 

 hitherto, offers practical medicine a peculiar mode of investiga- 

 tion, which greatly enlarges the doctrine of the physical symptoms 

 of the human organism, and for which the author suggests the 

 (German) name of " Erschutterangs-palpation." 



The Absorption of Organic Matter by Plants. — In a 

 communication from Prof. Calderon, of the Institute of Las 

 Palmas, Canary Isles, he contests the ordinary view that the 

 nitrogen of the tissues of plants is derived entirely from the 

 nitrates and ammoniacal salts absorbed through the roots. He 

 does not, however, adopt the old theory that the source is 

 the free nitrogen of the atmosphere, but rather the nitrogenous 

 organic matter which is always floating in the air. The nutrition 

 of plants he divides into three classes : necrophagous, the ab- 

 sorption of dead organic matter in various stages of decompo- 

 sition ; plasmophagous, the assimilation of living organic matter 

 without elimination, or distinction of any kind between useful 

 and useless substances, such as the nutrition of parasites ; and 

 biophagous, the absorption of living organism?, such as that 

 known in the case of insectivorous plants. A further illustration 

 of the latter kind of nutrition is, according to Prof. Calderon, 

 furnished by all plants provided with viscid hairs or a glutinous 

 excretion, the object of which is the detention and destruction of 

 small insects. To prove the importance of the nitrogenous sub- 

 stances floating in the air to the life of plants, he deprived air 

 of all organic matter in the mode described by Prof. Tyndall, 

 ■and subjected lichens to the access only of this filtered air and 

 of distilled water, when he found all their physiological funq- 

 tions to be suddenly suspended, 



