Page:Once a Week Jul - Dec 1859.pdf/80

. 28, 1859.] perfectly intelligible  that  inasmuch  as  organic matter is  said  to  form  the  indispensable  condition for the  development  of  the  eggs,  it  is  only  in  the vessel containing  such  matter  that  the  eggs  will develops; but why  are  they  not  also  visible  as eggs in the  other  vessels? why are  not  the  animalcules themselves visible  there,  as  they  were  in  the  water examined by  M.  Quatrefages? If both  eggs  and animalcules are  blown  about  like  dust  in  the  air, it is  an  immense  stretch  of  credulity  to  believe they will  only  be  blown  into  the  vessel  containing organic matter; but  the  opponents  of  Spontaneous Generation go  further  even  than  this,  for  they declare these  dust-like  animalcules  will  be  blown into a closed  vessel,  if  it  contain  organic  matter, but not  into  several  open  vessels,  if  they  only  contain distilled  water.

M. Quatrefages  is  on  better  ground  when  he rejects  the  evidence,  long  supposed  to  be  so  weighty, of parasitic  animals. He refers  to  the  modern investigations which  have  not  only  made  the  generation of  these  parasites  intelligible,  but  in  many cases have  demonstrated  it. M. Pouchet’a  reply  is feeble,  and  unworthy  of  a physiologist  of  his  eminence. He doubts  the  truth  of  the  results  obtained in  Germany,  Italy,  and  Belgium: “the monopoly  of  which,”  he  adds,  “has,  by  a strange anomaly,  belonged  to  foreigners.”  Because  France has  not  the  honour  of  this  splendid  discovery,  the Frenchman  begs  to  doubt  its  value! Every physiologist, however — not  French — will  be  ready  to admit  that  whereas  the  parasitic  animals  formerly furnished the  advocates  of  Spontaneous  Generation with their  most  striking  illustrations,  the  investigations of  Von  Siebold,  Van  Beneden,  Küchenmeister,  Philippi,  and  others,  have  entirely  changed the whole  aspect  of  the  question,  and  given  the opponents of  Spontaneous  Generation  new  grounds for believing  that  in  time  all  obscurities  will  be cleared  away,  all  contradictions  explained.

In conclusion,  I must  say  that  as  far  as  regards the particular  discussion,  M.  Pouchet  seems  to me  to  have  the  best  of  it. Their objections  to  his experiments are  all  set  aside. If the  facts  are  as he  states  them — and  his  antagonists  at  present  do not  dispute  the  facts — their  criticisms  go  for  very little. They have  not  shown  it  probable  that  any germs could  have  been  present,  under  the  conditions stated  by  him. Are we,  then,  to  accept Spontaneous Generation  as  proven? By no  means. It is  very  far  from  proven. The massive  preponderance of  fact  and  argument  against  such  an hypothesis  forces  us  to  pause  long  before  we accept  it. What M.  Pouchet  has  done  is  to destroy  many  of  the  arguments  against  Spontaneous Generation,  and  to  have  devised  experiments which  may  finally  lead  to  a conclusion. It is still  on  the  cards  that  some  source  of  error  as yet  overlooked  vitiates  his  experiments; but  until that error  has  been  detected,  he  must  be  considered to  have  on  his  side  the  evidence  of  experiment, whereas  we  have  on  our  side  the  massive evidence of  extensive  inductions. His experiment may be  conclusive,  and  an  exception  to  the  general law will  thereby  be  established  But  it  may  also, on further  investigation,  turn  out  to  be  illusory; some little  oversight  may  be  detected  which  will rob the  experiment  of  all  its  force.

Perhaps you  will  ask  why  this  suspicion  should be entertained? Why ought  we  not  to  accept  M. Pouchet’s  statement  with  confidence,  although  it does  contradict  our  inductions? The reason  can only be,  that  the  massive  weight  of  these  inductions naturally  predisposes  the  mind  to  believe that it  is  more  probable  the  experiment  which contradicts them  should  be  misconceived,  than that they  should  be  contradicted. Two years  ago I became acquainted  with  an  observation  made  by Cienkowski,  the  botanist,  which  seemed  finally  to settle  this  question  of  Spontaneous  Generation,  to place  the  fact  beyond  doubt,  because  it  caught Nature in  the  act,  so  to  speak,  of  spontaneously generating. Cienkowski’a statement  is  as  follows: If a slice  of  raw  potato  be  allowed  to  decompose in a little  water,  it  will  be  found,  after  some  days, that the  starch  grains  have  a peculiar border, bearing a strong  resemblance  to  a cell-membrane. This shortly  turns  out  to  be  a real  cell-membrane, and  is  gradually  raised  above  the  starch-grain, which  grain  then  occupies  the  position  of  a cell- nucleus. Thus, out  of  a grain  of  starch,  a cell has  been  formed  under  the  observer's  eye.  Inside this  cell,  little  granular  masses  are  developed, which begin  to  contract. Finally, minute  eel- like animalcules are  developed  there,  which bore their  way  through  the  cell-wall  into  the water.

Funke in  his  report  of  this  observation,  which he says,  he  has  verified,  asks,  how  is  it  possible  to deny  Spontaneous  Generation  here? Before our eyes a grain  of  starch  becomes  a cell,  in  that  cell  are developed  living  forms,  which  bore  their  way  out.

The reader  will  imagine  the  sensation  which such an  observation  created. He will  agree  with Funke, as  I did,  that  if  the  fact  were  as  he  stated it, all  discussion  was  at  an  end. But was  the  fact as stated? I tried in  vain  to  verify  it. Not less than twenty  separate  potatoes  were  employed, always in  conjunction  with  ordinary  starch,  as  a point  of  comparison; but  although  the  animalcules were abundant  enough,  I never  could  satisfy myself of  the  first  and  all-important  step,  namely, the formation  of  a cell  wall  round  the  starch-grain. This was  the  more  distressing,  because  it  is at  all  times  unpleasant  to  be  unable  to  verify an observation,  especially  one  made  by  a careful and competent  observer,  and  described  in  precise terms.

I could not  reject  what  Cienkowski  had  positively affirmed,  and  Funke  positively  confirmed, and was  willing  to  suppose  that  there  was  some necessary condition  in  the  observation  which  I had not fulfilled. On the  other  hand,  I could  not reject a doctrine  on  the  strength  of  a fact  about which any  doubt  was  permissible. In this  state of suspense  I had  the  satisfaction  of  hearing  from Professor Naegeli,  the  celebrated  microscopist,  that he too  had  been  baffled  at  first  in  the  attempt  to verify  this  observation,  but  that,  after  nearly  a hundred  trials,  he  had  succeeded. He positively confirmed all  the  statements  Cienkowski  had  made. But, from  that  moment,  my  suspense  vanished. If the phenomenon  was  of  such  rare  occurrence,  there were reasons  for  suspecting  some  other  explanation than that  of  Spontaneous  Generation. What the source  of  the  error  was  might  not  be  easily  divined;