241 



INFUSORIA. 



INFUSORIA. 



2;3 



carbon, hydrogen, nitrogen, and oxygen, are capable of uniting to form 

 water, carbouic acid, and ammonia, there they may be expected to be 

 found. The composition of the liquids in which they are found seems 

 to determine the forms they assume. One set of forms inhabits salt- 

 water, another fresh. Every mineral spring has its peculiar inha- 

 bitan . The sulphureous springs of the Pyrenees, the chalybeate 

 wateis of the Rhine, the siliceous, calcareous, and aluminous waters of 

 Europe, all contain them. They are found with the red snow of the 

 Alps ami the poles, and with the Conferva t/iermalis of the hot springs 

 of Aix and Baden. They are always accompanied with plants. Perhaps 

 it would be wrong to call any beings animals that are not found 

 feeding on plants, as it seems to be a law of organic existence that 

 plants should subsist on mineral matters, and animals on organised 

 matters. 



What are the uses of these beings ? To this question Professor Owen 

 gives the following reply : " Consider their incredible numbers, their 

 universal distribution, their insatiable voracity, and that it is the 

 particles of decaying vegetable and animal bodies which they are 

 appointed to devour and assimilate. Surely we must in some degree be 

 indebted to those ever-active invisible scavengers for the salubrity of 

 our atmosphere. Nor is this all : they perform a still more important 

 office in preventing the gradual diminution of the present amount of 

 organised matter upon the earth ; for when this matter is dissolved 

 or suspended in water, in that state of comminution and decay which 

 immediately precedes its final decomposition into the elementary 

 gases, and its consequent return from the organic to the inorganic world, 

 these wakeful members of nature's invisible police are everywhere 

 ready to arrest the fugitive organised particles and turn them back 

 into the ascending stream of animal life. Having converted the dead 

 and decomposing particles into their own living tissues, they them- 

 selves become the food of large Infutoria, as the Rotifera, and of 

 numerous other small animals, which in their turn are devoured by 

 larger animals, as fishes ; and thus a pabulum, fit for the nourishment 

 of the highest organised beings, is brought back by a short route from 

 the extremity of the realms of organic matter. 



"There is no elementary and self subsistent organic matter, as 

 Buffon taught; the inorganic elements into which the particles of 

 organic matter pass by their final decomposition, are organically 

 recomposed and fitted for the sustenance of animals through the 

 operations of the vegetable kingdom. No animal can subsist on inor- 

 ganic matter. The vegetable kingdom thus stands, as it were, between 

 animal matter and its ultimate destruction ; but in this great office 

 plants must derive most important assistance from the Polygastric 

 Infusoria. These invisible animacules may be compared, in the great 

 organic world, to the minute capillaries in the microcosm of the 

 animal body, receiving organic matter in its state of minutest subdivi- 

 sion, and, when in full career to escape from the organic system, 

 turning it back by a new route towards the central and highest point 

 of that system." 



Fotsil Infutoria. 



Many of the species of the Polygastrica of Ehrenberg, are covered 

 with a siliceous shield or shell, which is quite impenetrable. These 

 forms are those which are now recognised as belonging to the LHato- 

 macea. [DiATOMACE*.] The forms of Infutoria which are found fossil 

 belong chiefly to this section. They are frequent in all the varieties of 

 water which have been exposed to air and light, and in all the conditions 

 of this element between the extremities of terrestrial temperatures, 

 not absent even from snow, ice-covered streams, or the ejections of 

 volcanoes, they have been recognised in all the regions of the globe. 

 Lakes, rivers, and the sea are in places richly replenished by them, 

 and their siliceous integuments falling through the water accumulate 

 into extensive deposits. In regard to such accumulations in the sea, 

 we have the evidence of soundings by Captain Sir J. Hoss in the 

 course of the antarctic voyage ('Annals of Nat. History," Oct. 1845) 

 and Ehrenberg's examination of the deposits at Cuxhaven ; and their 

 abundance in fresh waters is matter of universal occurrence. These 

 deposits consist of the siliceous integuments of the Infusoria, and as 

 only a small proportion of the families are protected with siliceous 

 coverings, and as the waters which nourished them contain but little 

 silica, while the deposits are very extensive, we naturally associate 

 with these facts the idea of long-elapsed time. 



On turning to the marine and fresh-water deposits of earlier date, 

 this impression of the long duration of natural agencies becomes much 

 heightened. When, conducted by Ehrenberg, we find beneath the 

 Bohemian Mountains, and in the plains of North Germany, pleioceue 

 deposits many feet in thickness, composed of little else than the thin 

 flinty loricoc of Microzoaria, and following Professor Rogers and Mr. 

 Bailey, who dug up myriads of other forms from the meiocene strata 

 of Virginia, while Mantell and Reade exhibit to us Infusora from the 

 chalk and the Kimmeridge clay of England, we must add to the historic 

 time during which it can be proved these organisms have lived 

 the large indefinite geological periods of Cainozoic and Mesozoic 

 formations. 



The source of the siliceous matter which enters the organisation 

 of these beings is not difficult of discovery. Most of our fresh- 

 waters contain silica, though not in abundance, derived, it is probable, 

 from the decomposition of felspar and other mineral silicates. Silicate 



XAT HIST. DIV. VOL. III. 



of soda and silicate of potash, thus occasioned, may by intermediate 

 vegetative processes yield the silica in a state suitable for being 

 organically solidified. In the hot waters of volcanic foci, silica is 

 dissolved abundantly, and it is necessary to keep this fact in view 

 while considering the extensive flint beds in chalk, the thick Poliers- 

 chiefer beds of Bilin, and other siliceous masses, the result of organi- 

 sation. The distinction of marine and fresh-water races, which runs 

 through all the larger animals and plants with such regularity as to 

 be termed a law of nature, obtains also, but leaa absolutely, in the 

 Infusoria. Some species live both in fresh and salt water, and many 

 at the junction of rivers with the sea. By comparing the living 

 oceanic and lacustrine races on a large scale, enough of difference 

 appears in their siliceous shields to authorise conclusions more or less 

 positive as to the marine or fresh-water origin of infusorial deposits 

 which contain identical or analogous forms belonging to earlier periods. 

 Thus the rich deposits of Richmond in Virginia appear to have been 

 formed beneath the sea ; the famous deposits of Bohemia, Berlin, and 

 Santa Fiora contain admixtures of marine and fresh-water tribes ; 

 while those of the Bann, in the county of Down, and Gainsborough and 

 Bridlington, contain a more considerable proportion of fresh-water 

 species. 



Infutoria of marine or jestuary origin have been found in a fossil 

 state very extensively in Europe, Asia, Africa, and America. Ehren- 

 berg has described many species from Greece (Zante and Egina), Italy 

 (Caltasinetta and Cattolica), and Africa (Oran), which occur in cal- 

 careous marls, referred by Ehrenberg to the age of the true chalk 

 deposits. These deposits are very extensive iu Africa, occupying the 

 whole coast of Oran and large tracts in Egypt and Arabia. (Portions 

 of this tract have however been described by M. Rozet as tertiary.) 

 In the undoubted white chalk of Denmark (Riigen), of France 

 (Meudon), of England (Gravesend and Brighton), Infusoria also occur, 

 but less abundantly. North America has yielded a great variety of 

 marine or partly marine Infutoria, especially at Richmond and 

 Petersburg in Virginia, at West Point in Connecticut, Rhode Island, 

 Massachusetts, and Maine. Brazil has also yielded similar deposits. 



Infusoria partly of marine and partly of fresh-water origin have 

 become familiar to us in the Polierschiefer '(polishing slate) of Bilin 

 and Planitz in Bohemia, and of the Habichtwald near Cassel, the 

 Bergmehl of Santa Fiora in Tuscany, the white marls in the peat of 

 Franzenbad near Egra in Bohemia, the peat deposits of Gainsborough 

 in Lincolnshire, and at the base of the Mourne Mountains in Ireland. 

 We find them to occur also in considerable plenty, but in limited 

 distribution, in the lacustrine deposits of the east coast of Yorkshire. 

 The Mauritius is added to these localities by Ehrenberg, and New 

 Zealand by Mantell, all the occurrences belonging to supra-tertiary eras. 

 Infusorial remains are very unequally congregated. The siliceous 

 marl (Kieselguhr) of Franzenbad consists mainly of Pfavicula viridis 

 (Jig. 6), now recent ; that of the Mauritius, of BacMaria, vulgaris 

 (fig. 7) ; that of San Fiora, of Synedra capitata (jig. 9) ; while that of 

 Bilin is composed of Oaillonella distant (fig. 8) almost exclusively. 

 (Ehrenberg.) 



Infutoria are mentioned in the moya (volcanic mud) of Mexico, and 

 in the edible clay of the river Amazonas, by Ehrenberg ; in the rock- 

 salt and the marl which accompany it at Cardona in Spain, by Marcel 

 de Serres; they are assumed by Ehrenberg to enter largely into the 

 composition of flint, which indeed readily shows Xanthidia anu 

 Pyxidiculce. The bog-iron ore (Raseneisenstein) common near Berlin 

 is composed chiefly of GailloneUa ferruginea. A kiud of semiopal 

 lying in nodules in the Polierschiefer of Bilin is composed of the same 

 siliceous reliquiae (Gaillondlce) as the true polishing slate, but they are 

 cemented together and filled by infiltrated siliceous paste. With the 

 Gaillonellte Ehrenberg finds spicula) of sponges. The Precious Por- 

 phyry Opal of Kaschau, and the Serpentine Opal of Koseruitz in 

 Silesia, has appeared to Ehrenberg of analogous composition. The 

 following tabular view given'by Ehrenberg of some of these facts will 

 be useful : 



1. Bergmehl 



2. Kieselguhr .... 



3. Polierschiefer . . 



4. Saugschiefer .... 

 6. Semiopal of Polierschiefer . 



The above consist entirely or partly of the shells of Dialomacea. 



6. Semiopal of the Dolerite 



7. Precious Opal of the Porphyry . 



8. Flint of the Chalk . 



9. Gelberde (yellow earth) 



10. Raseneisenstein ... 



11. Certain kinds of Steinmark, investing 



the Opal of Kaschau 

 The above are probably of the same nature. 



As examples of undoubled marine Infusorial Fossils, the following 

 figures of some of the forms most frequent in a white deposit from 

 Richmond may be taken : 



B 



> Newest Formation. 



> Tertiary Formation. 



> Pyrogenous Rock. 

 Secondary Strata. 



Newest Formation. 



