58 Prof. Owen on Life and Species. 
observed formified corpuscles by oes bacteriums have been 
seen to be built up; and, that the chemical treatment to — 
which they had been subject, in thet extraction from the at-_ 
mosphere, would be likely to destroy the vitality of fecund 
germs, if any were present. To the alleged absence of am 
fst: red a power of i 500 diameters, and, once 80 seen, afters 
ward recognizable by a power of 750 diameters : whereas Pas- 
teur, in his quest, did not avail himself of a power exceeding — 
350 ‘diameters, and consequently failed to dotect the evidence _ 
of ‘nomogeny,’ under conditions as decisive as can be hoped — 
in an attempt to prove a negative. Against ‘panspermism,’ or 
the dogma that animalcules of infusions come, invariably ‘and 
exclusively, from pre-existing germs falling from the air, Pou 
chet records the results of experiments, conclusive or satisfac 
tory from their simplicity and ease of repetition, and freedom 
om need of minute, ambiguous, manipulatory precautions. 
A glass tube containing a filtered infusion is placed in the 
covering the vessels with the infusion. At the end of four or 
five days the tube-infusion has a thick film abounding with 
ciliate infusoria: the dish-infusion has a thin reticulate film 
containing only bacteriums and other small non-ciliate ‘micro- 
zoaires,’ It is ‘ difficult to see how the germs of the one kind of 
- creatures should have entered or become cb in the oné 
— and entirely different kinds in the o 
) the reader to cocxit” and vonkeee ‘for farther analy- 
ly resemble those of the ovarian ovum in Fish 
at either fig. 555 or fig, 416, vol. i. of the pe ; 
les panspermis , il n’y aurai urait pas de raison a 
monde qui ptit faire que, dans la méme rg dir Died age ap: en soit constam- 
ment remplie et la —. tages - bien ate 
ut étendue ‘iter infiniment pl: 
Geox Pt 19, nd eoom Be 
