incisions, grow angulous, sharp and pointed. When the young animalcule has attained the size and form of the maternal part, the union continues still some time, and is soon separated, whilst the female animalcule advances towards death and dissolution, to repeat the above described process, and propagate in this manner its genus and species.
After having described the propagation of these animalcules, such as we have observed it, we shall venture to say a few words upon the question of aequivocal generation, which has been in our days a subject of so much controversy.
Reason speaks in its favour; I might almost say, acknowledges it, but the most direct and impartial observations seem to be in contradiction with it.
The water I put in contact with pure organic matter, with full certainty that no egg nor animalcule could have been mixed to them, and abandoned to putrefaction, has generated nothing, during 4—8 months, except polygastric Infusoria, some species of Monas and Colpoda, small Vorticellae, and very seldom a little Vibrio (Anguillula Ehrenb.).
The Naviculae, the Frustuliae, and in general the animalcules belonging to this series, object of the present observations, have never appeared but in cases where I could prove their external origin. I never found these animalcules (except the Oscillatoriae often generated in infusions) but in river or marsh waters, as well as all the more developed
