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SCIENCE-GOSSIP. 



containing one or more chambers, ihe shells being 

 perforated by extremely fine holes (foramen, an open- 

 ing), through which the creature is able to protrude 

 numerous improvised members. 



A foraminifer may be more scientifically defined as 

 a sea-li\-ing rhizopod, in which the body is protected 

 by a shell or test usually composed of carbonate of 

 lime, but sometimes membranous. The body, how- 

 ever complicated the shell may be, is simply ^a small 

 lump of granular, gelatinous sarcode, of a highly 

 elastic character, possessed of contractile p.)wers, and 

 generally ha\-ing a yellowish or reddish tinge. 

 Through the holes in the test, arms and l^s of a 

 temporary nature are protruded at will, consisting 

 of extremely long thread-like processes of sarcode, and 

 these have the peculiar property of interlacing and 

 again uniting after emission. In this way they 

 somewhat represent an appearance, in miniature, of 

 an animated spider's web. The only traces of 

 o^anisation in this lowly creature are what are 

 known as the "nucleus" and the "contractile 

 vesicle." The nucleus is a rounded mass in the 

 interior of the animal, of a granular consistency, and 

 is thought in some way to be connected with the 

 process of reproduction. The contractile vesicle is 

 perhaps the more interesting of the two, in the light 

 of our present knowledge, for in this we appear to 

 have the humblest possible representation of the 

 heart of the higher animals. If the vesicle be 

 watched, in an amoeba, for instance, since in this 

 there is no shell or test to obscure obsenation, a clear 

 opening seems to make its appearance at a particular 

 place, and gradually expands within certain limits, 

 after which it again contracts in the same gradual 

 manner, until it finally apparently disappears alto- 

 gether. After a short period of quiescence, it again 

 commences to expand in a similarlv deliberate 

 manner, followed by the process of contraction. It is 

 thought that the digestive fluid is forced throughout 

 the organism by the contraction and dilatation of this 

 littlespot, undoubtedly a permanentorgan. Thusin these 

 lowly animals we find the combined elements of the 

 circulatory and digestive systems of the higher. The 

 thread-like processes which they emit are known as 

 pseudopodia, and throughout these a kind of circula- 

 tion of minute granules is kept up. Foraminifers are 

 still living in vast numbers, and in numerous species. 

 .■\mongst theliving monothalamous (single-chambered) 

 species may be mentioned Lageiia, Groinia, Miliola, 

 and Orhtilina. By far the greater number are, how- 

 ever, polythalanious, that is, they consist of numerous 

 chambers. Among the belter known of these are 

 Nodosaria, Clobigerina, Discorbina, the nautiloid 

 .shell, Liluola, Te.x/iilaria, Nonionina, Rotalia, 

 CrisUllaria, Puh'iniilina and Orbulina. 



It has been necessary to glance at some of the living 

 species, in order to properly appreciate the formation 

 of chalk. .\s already pointed out, it is a remarkable 

 fact, that under the microscope a piece of true chalk 

 will resolve itself into countless nunil)ers of these 

 minute fossils, the ancient representatives of 

 some of the species we have just mentioned. Globi- 



gcriiia buUoidis was apparently a very conmion 

 foraminifer in cretaceous limes, and is found to con- 

 stitute a large percentage of the whole, in many 

 chalks. On the other hand, occasionally Tcxliitcuia 

 and Bulimiiia are the chief constituents. Globigcrina 

 is especially abundant in the chalk rock of Berkshire, 

 Buckinghamshire, and Bedfordshire ; also in outcrops 

 of the same stratum around the Weald, in the south- 

 east of England. In some phosphatic chalk from 

 Southerham Pit, near Lewes, Mr. F. Chapman found 

 the species of Clobigerina known as G. marginata to 

 be very common, almost to the exclusion of G. 

 btilloides, whilst contained in it were no less than 

 forty other species of these minute tests. Most 

 prominent among them were the fossil forms Tcxtit- 

 laria, Triiaxia, Spiroplccta, Gaudryina, Biilimina, 

 Cristdlaria, Aiioiitalina, and Rotalia. 



Some genera, such as Frondicularia, Btilimina, 

 and CrisUllaria, are fairly common throughout the 

 « hole of the formation. On the other hand, there 

 are certain forms, such as Nodosaria, Polyinorphina. 

 and Rotalina, which are mostly found in the upper 

 chalk. The beds at lower levels are more character- 

 istically represented by Texlularia, Rotalia, Clobi- 

 gerina, and Lagena. 



(To he continued.) 



NEW FOR.AI OF PRUNUS. 



By Bern.\rd Piff.^rd. 



YoL"R botanical readers may be interested in the 

 following description of a species of Pniniis growing 

 wild over an extended area, and in considerable 

 quantity, in this neighbourhood. I have shown it to 

 two leading authorities and both are agreed it is not 

 the common sloe, but they widely difi'er as regards the 

 species. It is much less vigorous than the common 

 wild plum, and diflfers from it in the very small blossom 

 and smaller leaves. It difl'ers from the sloe in that 

 it blooms .some weeks earlier, and leafs at the time it 

 blossoms. The bark is not black, the previous year's 

 growth being green. It is thomless and less 

 branching. 



It extends over a considerable space on some low 

 land through which an extinct river seems to have 

 flowed into the Boxmoor \"alley. .\s the land rises 

 again before the river entered the valley, the space 

 the shiub now inhabits must have formerly been a 

 swamp. 



It is needless to say I shall be willing to visit the 

 place with any of your readers who may wish to 

 examine these shrubs. The locality is about half a 

 mile from Boxmoor Station. 



Hc'iiel Hempstead. 



ThkOi.d Physics G.XRiiF.N on theChelsea Embank- 

 ment, which was at one time threatened with ex- 

 tinction, is to be in the future under the management 

 of a committee consisting of seventeen persons. The 

 charity and its endowmcnls are to be administered 

 exclusively for the promotion of the study of botany. 



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