Life and

42 The origin of life
be “teeming with vibrios”. The author concluded that organic matter, left to itself,
protected from any germs, would give rise to microphytes (végétations microscopiques),
while water was necessary for the formation of infusorians (animalcules infusoires)
(Donné 1866). Pasteur, in his commentary attached to the published note, severely
doubted the validity of Donné’s procedure, suspecting the introduction of germs
during the handling of the eggs. Donné’s response was surprisingly caustic. He
repeated the description of one of his experiments, with some variation on the
original series: He had pierced the yolk (le jaune) with a scalpel first brought to red
heat in a flame, let about one third of the liquid drip out and replaced it with
boiling distilled water, sealing the opening with hot wax. After five days at room
temperature, he found the liquid inside the egg teeming with highly agile vibrios;
these, he presented as incontrovertible proof for spontaneous generation, as
[o]n ne peut pas raisonnablement admettre qu’ils préexistent dans la matière de l’œuf ;
j’ai démontré qu’il ne s’en développe jamais dans les œufs abandonnés à leur
décomposition naturelle. On ne dira pas non plus, je pense, qu’ils sont contenus dans
l’eau distillée (Donné 1867).
In the spring of 1868, Balsamo and Maggi repeated Donné’s experiments. Initially,
following the Frenchman’s instructions literally, they were able to reproduce his
findings. Continuing their observations beyond the immediate establishment of
the presence of vibrios, they also described the formation of vesicles containing
nucleate granules, which originated by fusion of yolk platelets (granuli vitellini):
heterogenesis happening under the lens of their microscope. Then, the authors
decided to investigate the exact conditions leading to the creation of different
forms of micro-organisms, setting up ten more series of modified experiments.
They assembled a complex apparatus to control the atmosphere in which the eggs
were incubated, rinsing the air in sulphuric acid. In later experiments, the eggs
were placed under water inside a vessel ventilated with air passed through
sulphuric acid, and then crushed, observing the coagulation of the albumin in the
surrounding water. Examining the developing organisms in twenty-four-hour
intervals, the authors observed their further evolution, depending on the
controlled conditions of each series of experiments, developing from small,
rounded bacteria and vibrios into filiform Leptothrix (M6). 133 As an additional
confirmation of their findings, Balsamo Crivelli and Maggi invited their colleague,
the physicist Giovanni Cantoni, to examine their experiments (M8). 134 The latter
had already undertaken extensive research into the issue in previous years,
133 The term leptothrix (Greek λεπτόθριξ: of fine hair) was intended to refer to a genus of organismic
species, though it was mainly a morphological description of protozoans. The form is not
Italianised and equally used unchanged in the plural, as is the case with vibrio.
134 The resulting paper, published in identical form both in the Rendiconti and in Nuovo Cimento, has
been included in Maggi’s official list of publications (M272, under M8), although it exclusively
carries the name of Cantoni.