606 Original Articles. [Oct., 
have interested themselves in the controversy, and that is, the paucity 
of information afforded on both sides of the debate, as to the exact 
nature of the forms discovered in the infusions ; for, generally speaking, 
we hear only of vibriones, monads, bacteriums, terms (if I may venture 
to say so) which have no accurate scientific meaning, and which 
represent only moving specks of the most obscure character. 
This circumstance is to be explained by the fact that the most 
striking experiments have been performed by persons almost entirely 
unacquainted with micro-zoology, or who hold exploded views on 
many matters connected with that branch of science. 
In entering upon a brief description of my personal experiences in 
connection with this subject, I fear that my labours will not have 
been lightened by the last criticism ; but however small may be the 
value of the evidence which will be adduced in aid of the solution of 
this problem, my readers may rest assured that there has been no 
want of care in the identification of the forms described. Again and 
again evidence has been rejected by me as insufficient, because the 
living forms under examination would not admit of accurate descrip- 
tion, and the few isolated data which follow have been selected from 
a mass of notes and sketches, many of which might have been added, 
were it not for the imperfection of their details. 
It is eight or nine years since my attention was first directed to 
the subject under consideration, and from that time to the present I 
have, year by year, conducted experiments with a view to test the 
validity of the doctrine of “ spontaneous generation.” 
The conflicting evidence which was from time to time published 
by trustworthy and eminent investigators, and the great difficulties 
that had to be encountered in the shape of adverse weather, the 
frequent necessity to leave my work unfinished, &c., prevented me 
until recently from stating what had been the results of my observa- 
tions ; and it has only been within the last few weeks that they have 
been of a sufliciently positive character to justify my coming to a 
definite conclusion on the subject of heterogenesis, in the present 
signification of the term. 
defect had been, according to his views, that the disputants had not observed 
with sufficient accuracy; and he proceeded to state, as the result of his careful 
investigations, that the polygastrica have many bond-fide stomachs; that the 
number and diameter of these stomachs is fixed in each fully-developed species ; 
that they never coalesce, for it is easily perceptible that they have distinct mem- 
branes (“des parois distinctes”’), and thatthe pretended rotation of these stomachs 
is an optical illusion! (Séance de Academie, 13 novembre, 1848: ‘ Comptes 
Rendus,’ xxvii. p. 516.) 
It is hardly necessary to state that nearly ali these observations have since 
proved incorrect; and as the learned French anatomist has never acknowledged 
his mistakes, one of two conclusions is therefore inevitable, viz. that he either still 
unconsciously holds antiquated and inaccurate views, or that when once he has 
made his declaration on a biological subject, there is no great probability of his 
afterwards bestowing upon it an unprejudiced consideration. 
As to the recent “commission” appointed by the Academy of Sciences to 
decide between Pouchet and Pasteur, and which ended in the premature (and it 
appears to me justifiable) withdrawal of Dr. Pouchet, the whole affair had too little 
of the air of seriousness about it to warrant its being considered in this place. 
