INFUSORIA. 



INFUSORIA. 



Mi 



DJTU 



Beside* these be discovered, to hii mat 

 Bt gelatinous or quit* *oft cyste, which 



only a single Rqlmu contracted into a globular 



^, two of hnkpberio.l form appreeeed together. 



The encysted JajfinaT proved to be itill living, inasmuch as they 

 Bored about in the cyst*. an<i if the oyiU were ruptured the previously 

 globular individuals reaaeumed their prUtine elongated figure, and 

 crawled about in the mate manner as the other beakles* individual* 

 [theOc/erwt. 



what purpose was thii encysting? The cyst wa* evidently 



4 for mnsihinf more than a coffin. Farther observation* won 



Aimeil that the encysting proces* of the Eugtam had really reference 

 to their mnltjplkjatiotLThe procinei however appeared to be different 

 fa JhsyiaM from that in (frtgarina, inuoiuch u in the latter case two 



JWUi 

 individual* 



they had proceeded from the divisic 

 TiduaL Whilst thu* investigating U 

 directed to other forma of Jnfnturia 



are conjoined before the cyit u developed, wliiUt in the 

 i U formed usually around but one ; for where two 

 found incloeed in a cyst, it wa* at once apparent that 

 from the divicion of an originally single indi- 

 cating the EuglaKe hi* notice was also 

 'n/utona contained in the aame water, 



as Poroawctiut aurttia, Pnrvdm mrrw, and Holopkrya ditcolor, 



the latter two of which special he frequently observed inclosed in 

 well-defined gelatinous cysU ; and u these /n/iuoria belonged to 

 quite another principal division of the class, he began to hope that 

 the procees of becoming encysted would probably turn out to be of 

 general occurrence in the infusory world. 



This proved to be the oaae, and the work then proceeds to describe 

 the way in which Dr. Stein was led to detect the connection between 

 Kf^tftu fliealilu with a species of Ehrenberg's genus Acintta, an 

 ubesnstion which pointed the way in his future researches. One of 

 hie earliest additional observations was that of the heterogeneous 

 generation of Eputytu dtgitalit. In this species he traced first the 

 metamorphosis of the Epiilylu into an Acintia , and, secondly, 

 observed in the latter the extraordinary fact of the development and 

 volution of a TritoJiiui, a diecovery which Ehrenberg has attempted 

 to explain by the supposition that the Tricwiina had been previously 

 swallowed by the Acituta. Dr. Stein's important researches are 

 continued through the family of the Vortictttvue, and his observations 

 given upon Ariimopkryt, Podophrya, the genus Tricodina, and on the 

 tare of the OpaJuur, the propagation of the CHIoroyonium evcUorum 

 and VurtKtUa mimttoma, and particularly upon the quiescent con- 

 dition of the latter /nftuoria; upon Spirockotia gemmipara and 

 & &fa*loiii, and upon the Acinrla state of Dendrocomtttt paradaxus, 

 " Ac. Ac. (' Quarterly Journal of Microscopical 



S 1 July, 1864.) 

 At the preeent time it would undoubtedly be premature to state thnt 



' 



probably better to substitute the term Protozoa, to 

 '* organisms having au animal character, and yet presenting the 

 simple conditions that we find amongst the A'ottockinetr, and 

 ether froups of lowly-developed plants. We may state generally that 

 Ehrenberg Polj/gattrie* embrace the following group* of beings : 



1. True plant*, as in the Dumidra (Clotttrina), Volvociaa (Crypto- 

 MsMsU***). and some other*. [UnuibEJc.] 



1 Organisms which the weight of evidence at present assigns to 

 the veritable kingdom, a* Matomaeta (BaciUaria, PragMaria, Ac.), 

 and a Urge number of the Monadtna and Vibrioniaa. 



3. The ova of JSmlotoa, a* Ctrtaria and others, and probably even 

 of hither animal*. 



4. Minute form* of animal* referable to previously-established 



W^. this seem* to be the case with the whole of the Vorticclliita, 

 may with more propriety probably be referred to llydroid than 

 to any other form of polypiferoua animal*. 



6. Dujardin has pointed out the identity between the structure of 

 enaniem* like AmaU with *noh form* a* IHglvyia and ArceUa. In 

 all these creatures there is no trace of mouth or digestive cavity, aqd 

 he entire body i* a single cell or an aggregation of cells, which 

 derive* it nutriment by absorption from without. Professor Kolliker 

 has recently described the method by which one of these creatures, 

 the ArltmofJu-f,. takes it* food : 



M A* regards the vegetable functions," says the Professor, " the mode 

 in which the Attimofirft I* nourished is one of the highest and most 

 special interest. Although the creature ha* neither mouth nr stomach, 

 yet it take* in solid nutriment and rejects what is indigestible. I'll is 

 null, for so it may almost be called, i* thus effected with minute 

 Cnistsnuni ( Kaii/tra. minute species of /.yiirou, the young of Cfctaf*, 

 Ac.) and the lower Alya (lAalommenr, spores of KancAerM, CUtHtrwrn, 

 etc.). When in ite progress through the water it approaches one of 

 little plant*, or when an /s/nsertsm ha* come into proximity 

 it, both plant and animal a* *non a* they touch one of the 

 Ur nlanwnte, usually adhere to it Now, as the filament 

 with He prey slowly shortens itself, and the Utter approaches the 

 surface of the body, all the surrounding tilarneuU apply themselves 

 upon it, brnding their points together so that the captive Hirejmt. 

 gradually inclosed on all *W According to all appearance, these 

 hniMH ill ii become more or less shortened. In this way the morsel 

 it gradually brought to the surface of the body, the filament by which 

 it was *susd being anally so much shortened a* to disappear alto- 



gether, and having, as not unfrequently happens, relinquished its hold 

 upon the prey, after the latter ha* become encompassed by the sur- 

 rounding filament*. These gradually apply themselves more and 

 more cloeely together around it, forcing it toward* the surface of the 

 body. 



"The following proceeding now takes place : The s|K>t of the 

 surface upon which the captured animalcule U lying slowly retract*, 

 and form* at first a shallow depression gradually becoming deeper and 

 deeper, in which the prey, apparently adherent to the surface and 

 following it in it* retraction, u finally lodged. The depression by the 

 continued retraction of the substance now becomes deeper; the 

 imprisoned animalcule, which up to this time had projected from the 

 surface of the Actinophryt, disappears entirely within it; and at the 

 same time the tentacle*, which had remained with their extremities 

 applied to each other, again erect themselves and stretch out as before. 

 Finally, the depression acquires a flak-like form by the drawing iu of 

 it* margin, the edges of which coalesce, and thus a cavity closed on 

 all side* is formed in which the prey U lodged. In thU situation it 

 remains for a longer or shorter time, gradually however approaching 

 the central or nuclear portion, and at last passing entirely into it, iu 

 order to await its final destination. In the meanwhile the external 

 portion of the Actinopkryi regains in all respects its pristine condition. 

 The eugulphed morsel is gradually digested and dissolved, as is readily 

 seen by ite change of appearance from time to time. It' entirely 

 soluble, as for instance an Infiuorium, the space in which it U con- 

 tained contract* a* the dissolution of it* content* goes on, and finally 

 disappears altogether. Should there be however an indigestible 

 residue (a membrane composed of cellulose, a portion of chitine, a 

 shell of a Lynceui, or case of a rotifer, Ac.), a passage for it* exit is 

 formed, and it is expelled by renewed contractions of the homogeneous 

 imbalance, and in the same direction, or nearly so, u that which the 

 morsel followed in ite introduction. The passage and the opening 

 through which the expulsion was effected disappear again without 

 leaving any trace." 



In the A ctinophryi we have an animal cloeely resembling the creature 

 which inhabit* the xhell of the large family known now as Furaminiftra 

 [KOKAMIXIFEBA], and Dujardiu suggests that the loricated forma of 

 />i<Hu<jia and Arcella are transitions to the more decided form* of 

 Foraminiftra. Hence he proposes to include several form* of 

 Ehreubeiy's Jnfutoria, with the Furaminifera or Polythalamia, under 

 the term Rhizopoda. Little therefore i* left us to say of what may 

 be regarded as true Polygattrica. They all appear to have a distinct 

 mouth or entrance to the cavity of the body, and this is usually 

 surrounded by vibratile cilia, as seen in the cuts of .Voiioj atomot and 

 Lcucop/tryt patula. These cilia apparently bring the food to the 

 mouth of the animal. An anal orifice i* described by Kbreuberg in 

 the majority of Bpecies. When finely divided soluble colouring- 

 matter as carmine or indigo (a writer in the ' Microscopical Journal ' 

 recommend* the red pigment which line* the cornea of the common 

 house-By) i* introduced into the water in which they are contained, 

 the transparent body of the animalcule is speedily seen to be studded 

 with coloured globules, consisting of au aggregation of the particles 

 of colouring matter. Ehrenberg regarded these globule* as distinct 

 sac*, which he supposed were given off from a central intestinal 

 canal, as seen in ieucophryi patula. Regarding these sacs as so many 

 stomachs, he gave them the name of Potyyattrica (many-stomached). 

 It is however still a question as to whether in any case these masses 

 are contained in a distinct sac. The whole body of the animalcule i* 

 often covered with vibratile cilia (see cut of Leucophryt), and it is to the 

 constant action of these organs that the varied movement* of these 

 animalcule* are due. [CILIA.] The movement* thus effected are 

 !y automatic, and iu no way connected with any intelligent 

 consciousness. All the movements of these animals are not due to 

 cilia, as the whole of the tissue of the animal is observed to contract 

 in Amttlia, Amjihilepltu, and the stalk of the Yurtitrllina. 



Although Klirvnberg has described a complicated apparatus for 



> -piodm-li 10 instance* of conjugation are recorded amongst the 



true Pvlygaitrica. Their mode* of multiplication are by fission and 

 gemination. In a large number of cases a simple division of the 

 unicellular organism into two equal parts take* place. This process 

 goe* on so rapidly that, according to Ehrenberg, a single /'aromecttun 

 "ni.l produce 268,000,000 of cell* in a single month. From analogy 

 we must suppose this process would not go on continually, and, us 

 iu plants, we must regard the separate cells thus produced as belong- 

 ing to the same individual. Further observation is probably only 

 needed to demonstrate the existence of a union of two evils a sjieriu 

 veil and a germ cell as is now known to be almost universal in the 

 vegetable kingdom. In the account above given of Stein's researches 

 it will be seen, that it is not improbable that one of the modes by 

 which these beings are enabled to spring suddenly into existence, 

 is the production of winter-eggs, or reproductive bodies of a kind 

 that will resist the influence of au absence of moisture from the spots 

 iu which they ordinarily abound. 



The true /'ulyyiutrica seem universally diffused. Wherever organic 

 matter exist* iu a decomposing state, there they abound. They exist 

 in incredible numbers in the waters of the ocean, iu rivers, lakes, 

 linds, pools, and ditches. They are found in the secretions .>! the 

 higher animals, and eruu iu nun. Wherever tue organic elements, 



