Page 88 - Ethel D. Hume - Bešam ili Paster: Izgubljeno poglavlje u istoriji biologije

RIVAL THEORIES AND WORKERS 85

place the microscope slip in a Petri dish containing a thin
stratum of water (so as to prevent evaporation from
beneath the cover-glass) and fixing upon one of the tail
setae (these being larger than those of the abdominal feet),
we may examine it from time to time. What may be ob-
served is this. After an interval of two or three days (the
duration depending upon the temperature of the air at the
time) we may see, under a high power of our microscope,
scarcely visible motionless specks gradually appear in
increasing numbers in the midst of the structureless proto-
plasm, and, still later, we may see some of these specks
growing into bacteria. ... At last the whole interior of
the spine becomes filled with distinct bacteria. . . . Later
all the bacteria, previously motionless, begin to
still,
show active swarming movement. In such a case it is clear
we have to do with no process of infection from without,
but with a de novo origin of bacteria from the protoplasmic
contents of the spines or setae. The fact that they appear
in these situations as mere separate motionless specks, and
gradually take on the forms of bacteria (also motionless at
first) is, as I have previously indicated, just what we might
expect ifthey had actually taken origin in the places where
they appear. On the other hand, such a mode of appear-
ance is totally opposed to what might be expected if the
micro-organisms had obtained an entry from without,
through the tough chitinous envelope of the spines."
Professor Bastian gives numerous examples of the
finding of bacteria in internal animal organs and in fruit
and vegetables, where he demonstrates the impossibility
of an invasion. Can the followers of Pasteur provide any
solution of the mystery? If they cannot, it must be con-
ceded that no "mortal blow" at the doctrine of spon-
taneous generation was struck by Pasteur, as he proudly
boasted. The dealer of the blow, or, at any rate, the pro-
vider of an explanation, apart from heterogenesis, was not
the French chemist, dilating to a fashionable audience
which included "all Paris," but a hard-working French
Professor and physician, who was also a chemist and a