On this page

• Text (2)

  Note: This text has been automatically extracted via Optical Character Recognition (OCR) software. The text has not been manually corrected and should not be relied on to be an accurate representation of the item.

  • 

    Untitled Article

  • 

    Untitled Article

• Transcript

  • Note: This text has been automatically extracted via Optical Character Recognition (OCR) software. The text has not been manually corrected and should not be relied on to be an accurate representation of the item.

    Additionally, when viewing full transcripts, extracted text may not be in the same order as the original document.

    Untitled Article

    , Wstand this on being informed that he , violating all Biology , declares fc Animalcules to be " organized , and the greater part of them ( probablylit liqhly organized bodies . " The supposed existence in these simple liular structures of organs so complex as gall-ducts , ganglia , eyes , &c . i ccompanied by any evidence of the presence of those tissues from h " \ i such organs are formed , or of those functions which they subserve ) / I ! maie the Biologist stare ; but what will he say to Ehrenberg ' s asser" ? . / 7 ) that " the power of infusorial organization is shown in this Hbition ' of a complete mental activity ! . '" We feel that it is only necesallusion to propositionTo disprove it

    to make an so outrageous a . ould be to insult the sagacity of the reader . It may serve , however , as ^ text for a s ermon on " Observation . " Having satisfied himself that Infusoria are highly organized , Ehrenberg liscorers that " they do not sleep . " The enunciation of this discovery is tructive , because it places the fact only as a probability . " They appear to be ( as far as is yet known ) sleepless . " He would not be surprised , therefore , to find them sleeping ? Did he ever ask himself what sleep was P Professor Owen , in his quiet way , thus disposes both of the " sleeplessness" of the " volitional activity" of these infinitesimal creatures : —

    « The motions of the JPolygastrica have appeared to me , long watching them for ' ndications of volition , to be in general of the nature of respiratory acts , rather than attempts to obtain food or avoid danger . Very seldom can they be construed s ' voluntary , but se em rather to be automatic ,- governed by the influence of stimuli within or without the body , not felt , but reflected wpon the contractile fibre ; and , therefore , are motions which never tire . We may thus explain the fact which Ehrenberg relates—not without an expression of surprise—namely , that at whatever period of the night he examined the living Infusoria , he invariably found them moving as actively as in the day time ; in short , it seemed to him that these little beings never slept . " The way these " organs " are discovered is simple . Ehrenberg observes i motion and infers a precedent volition , not conceiving that it may be

    automatic ; he observes a red speck , calls it an eye , and having so called it of course assumes a nervous system corresponding with it . " If no other proof than this could be obtained , " says Ehrenberg or Mr . Pritchard , speaking of the eye specks , " of the existence of a nervous system in these animated atoms , this might still be taken as a sufficient evidence of the fact . Yes , by microscopists , not by biologists ; in the absence of any proof of a nervous system the notion of an eye existing becomes baseless ; but the eye is assumed , and from that assumption a nervous system is deduced . See how this is done" The Rotatoria are not considered to possess a true nervous system , but in many of the species , having eyes , there appears one or two masses attached to them , which JEhrenlerg thinks are similar to nervous ganglia and nervous fibrillee . The eyes vary in number ; they are usually of a red colour ; in some they are placed upon a ganglion , and are freely moveable beneath tie transparent superficial envelope of the body . "

    Now what is the naked fact—what is there presented in observation ? The Microscope shows red specks , loose aggregations of coloured particles—why assume them to be eyes P In the spores of the Algae there are spots precisely similar , yet who calls them eyes ? But on this point hear Dujardin , whom Mr . Pritchard , with praiseworthy candour , quotes for his own refutation : — " The sense of sight would partake more of the oharacter of reality , if the colour of a speck without appreciable organization , without a constant form or a precise contour , sufficed to prove the existence of an eye . But , for instance , in the Eitf / fena , which are particularly cited as characterized by such an organ , the red spot so regarded is excessively variable , sometimes multiple , at other times made up of irregularly aggregated granules .

    " Analogy , too , is inadequate to the solution of tho question ; for , on descending tin * animal . series , to determine the nature of the coloured speck , wo have to leap from the Daphnioo ( members of the ICntomoslraca ) , witli a moveable eye , repeating Jn its composition thut of Insects and Crustaceans , to animals presenting nothing out ( liil ' used coloured specks . " Such spots , whether in number or position , have ho little physiological importance in tlits I Mamma ; , and in certain Annelides , that they are often not even to be employed us an absolute specific character . In the Kotatoria , tho analogy witli which is more especially insisted on , these pigment spots are , in some species ,

    Known to disappear from age , and in others to become , more evident , in proportion to siz « in- development of individuals : so that the lonrned micrographcr of . Berlin , i" his attempt to base the generic characters of these animals on the presence and number of the eyes , has been led to place in different genera , species very closely all >< 'd , if not identical . Indeed , that a black or red colour is in general an attribute 0 )' ' ] i (! pigment of (( yes , cannot Iki a reason for concluding an eye to exist wherever then ; is u red colour ; if so , indeed , we must , accord them to some intestinal worms , Ml ( 'h as tho Srol . cx po / gmorph / is , which has two red . spots on the neck ; to the actinia * , which are often ' strewed with such specks , and also to Home bivalvcd mollusks .

    " H ' Mui ability of the Infusoria , to direct their course through the liquid , and to pursue- their prey , be appealed to hi evidence , it is certainly , in the first place , neceNSiiry to verify the reality of this faculty , which I think equally fabulous with all ' luted concerning the instincts of these animals . Indued , it , would not won prove he red specks to be eyes , since the greatest , number of Infusoria supposed to be ^ "ibtwt-il \ vit , ) i sii < -h n / it < : uK , y , are in want of them ; and those which do possess "" '"i , do not , exhibit that , power in a higher degree of development . " ^ Y < ' quit hero a , controversy only commenced boeaiiHe wo deemed it | iKcfiil to indicate tlie dangem of too implicit a reliance on the " obflerva-!' IOI 1 H" «> l" tho rnicroHcopiHt , who like every oflior observer dei > ondn on kin "' felled ,,,,,, ! training more than on his eye ' tf . it is ( he mind and not the ( "">! ' ween , jin one needs often iterate . '" nistinjr about for an extract of general interest we found this , winch K (> '"ves to illnHtnito the idea ho often expreHKed in these columiiH—the inil >» Hil ) ilil , _ y of dmwiiig donmreating linen in Nature : —

    ' / h-v / it / c / . ion hctivcrn Infusoria and other Minufti Animals and Plants . — In | J " l > iv . scnt Nt , al ( , of knowledge , with respect to organic bodies , there are many ' '' '"i lti ( . s in the way of determining on such boundaries as may reduce them to U ('! defined groups . ' Even the line of demarcation between animnlM and plants ,

    which , at first sight , might be supposed to be so very broad and distinct , upon a more minute consideration , is not easily settled . Nor is this surprising , for if we turn to inorganic nature , we find the chemist is equally at a loss to separate the two grand classes into which he divides those bodies : namely , —metals and nonmetallic substances . While , at starting , they offer no resemblance , yet , by slight gradations , the bodies of each division approach the other where characters are still wanting to distinguish them . As examples , we may take the metal Silicium , which is sometimes regarded as a non-metallic body ; while , on the other side ,

    Iodine and Bromine resemble metals . In the organic world , no difficulty is found in separating the mammals , birds , and fishes , from forest trees and flowering plants ; but , as we descend in each kingdom , the lines of demarcation become less strong and decisive , until at length no single character is sufficient to distinguish them . Thus , motion , digestive structure , composition , the products evolved , &c , taken singly , are of little avail in separating an animal from a vegetable organism . Recent researches have rather increased these difficulties . The fashion of the present day is to magnify the arguments in favour of vegetable life and physical motions , while those on the side of an animal existence are slurred over . It is , therefore ,

    desirable to pause before offering an opinion , especially when every distinction hitherto proposed , is seen to vanish if rigorously tested . The organisms of a doubtful animal nature , are principally found in tbe families Hfonadina , Vibrionia , and JBacillaria , which are fully described in Part III . " 1 . Motion . This is an excellent animal character , where its voluntary and spontaneous nature can be clearly perceived , but in microscopic bodies , vision being obtained by one eye only , and that under unusual conditions , difficulties present themselves which do not occur in common vision . Again , the germs , or spores of minute Alga ) , and other vegetable organisms , swim about in water until they find

    a proper place for attachment , when they grow as a plant ; hence some naturalists have supposed that animal life is transformed into vegetable , as the name zoospores implies . ( See Vibrionia . ) The mollecular motions of Dr . It . Browne—namely , those seen under a deep magnifier in a drop of water , in which finely divided gamboge or other organic substances have been triturated ; these motions have been compared with the spermazoa of animals and plants , which are now considered as physical motions only . The circulation or cyclosis in plants , so well exhibited in the Chara , have been compared with the motions in the Closterina and Bacillaria , and hence they are only allowed a vegetable life . ( See M . Thuret on the Zoospores of Algse , Ann . des Sciences Nat . 3 ieme series Tom XIV ., 1850 . )

    " 2 . Cilia . The presence of these organs for locomotion , is a strong argument m favour of the animal nature of an organism , but alone are insufficient , as the minute spores of some Algae possess them . _ " 3 . Digestive Organs . The presence of a stomach would strongly tend to tho establishment of an animal , but plants have been discovered which possess a cavity for admitting water , and thus resembling a digestive sac in its simplest form . While if imbibition by the cuticle be admitted , the cells of plants approximate very closely to animals . The difficulties , however , arc greatest in the Desmidiacea and Diamomacea , to which the reader is referred to for particulars . " 4 . Composition . Tertiary compounds are claimed for the vegetable , but the Chlamidomonas , whose animal nature is undoubted , is only a tertiary compound . The presence of nitrogen was , sometime since , excluded from the vegetable , but it is now known that several plants contain azote .

    " 5 . Starch . The existence of the organic proximate clement , Starch , has been much insisted upon as determining this question , indeed its almost constant presence in plants , renders it a desirable test ; but , in the doubtful animal organism , their minuteness and the nature of their coverings , render it difficult of application ; indeed , in those cases where it is most needed , as the Desmidiecr ( which see ) it too often gives equivalent results . " 6 . The evolution of Carbonic Acid by Animal ? and of Oxygen by Plants , ha been proposed for determining this point , but the " Euqlcna viridis , whose animal nature is admitted exhales oxygen , as do some of the doubtful family Bacillaria and the Volvox globntor , the latter , however , has lately been claimed by the botanist . " 7 . Visual Organs . The existence of eyes would prove , beyond doubt , the animal nature of an organism ; but the red points considered as eyes , which exist in many of the Polygastrie Infusoria , are , by some naturalists , not admitted as eyes , similar red spots being observed in the spores of Alga ' , are adduced as confirmatory , of this position .

    " 8 . Conl . raclibili . ty has been proposed as a test . It applies only to the soft bodied forms , but M . Thuret says it is not peculiar to animals , but partaken also by the zoospores of Alga > . "{) . Multiplication by spontaneous division or fission . This method ofincrease has been adduced by IGhrenberg , as evidence of the animal nature of the Uaeillaria and other Infusoria , but , it is admitted , that the lissiparous division of vegetable cells is of it similar nature .

    " 10 . The non-occurrence of development by conjugation , has been latterly insisted upon us separating animals from plants , but , this distinction is now questioned . " The act ion of acetic acid and of electricity , on these minute organisms , have been proposed as tests , but hitherto the results have , been unsatisfactory . " This uncertainty in distinguishing plants from animals , coupled with the observation of" some peculiar phenomena in the production of spores in the lower Alga ; , led those distinguished naturalists , linger and Kiif / . ing , and others , to believe in the transition of some forms , from an animal to a vegetable existence , or vie /; vrrsa . It seemed to Kiit / . ing , that , there arc beings in which animal and vegetable life are so intimately blended , that the kind of existence manifested , will depend on the predominance of one or of thtr other , and this too , without a necessary change of form . "

    ] n conclunion we recommend this Jfisfonj of Infusorial Animalcules sin 2 i , repertory of faoLH and viewn which could only Ixi \ s , ol ul . hy extensive research .

    Untitled Article

    VIId , A < JK "I / IKK IN i : <;\ TT . Vilhiyo Lifoiii , M / . i / J > t , with KLctchcs of the Ha ' id . Hy Uuylo NL . John . "In 2 voIh . Clmpiiiiui mid Hull . In liia former work Mr . Buy lo SI . . John introduced iih to the domestic circle of a Levantine family ; in his pre . senl , work lie lias taken uh into the villages of JC ^ ypt , and hIiovvii iih many iin |> ecl , n of jx-aiHant life . Jlo Iijih a h Iron £ sympathy with the fellahs , and pleadn their causo with earnent eloijwenco and cogent reasoning . The evil influence of Mohammed Ali , in hia jljihruo ulLcmnl to introduce Jiuropcan civilization , although

    Untitled Article

    October 23 , 1852 . ] THE LEADER . 1021

• Citation
  • Leader (1850-1860), Oct. 23, 1852, page 1021, in the Nineteenth-Century Serials Edition (2008; 2018) ncse2.kdl.kcl.ac.uk/periodicals/l/issues/vm2-ncseproduct1957/page/17/