M. hyalina compressa. Flat transparent mona.
This is mostly found in salt water. It is of a whitish colour, more than twice as long as it is broad, transparent, with a dark margin, the motion vacillatory; it often appears as if double.
9. Monas Pulvisculus.
M. hyalina, margini virente. Transparent mona, with a green margin.
Little spherical pellucid grains of different sizes, the circumference green, a green bent line passes through the middle of some, probably indicating that they are near separating or dividing into two distinct animalcula; sometimes three or four, at others, six, seven, or even more, are collected together. They rove about with a wavering motion; and are mostly found in the month of March in marshy grounds.
10. Monas Uva.
M. hyalina gregaria. Transparent gregarious mona.
It is not easy to decide on the nature of these little assemblages of corpuscles, which sometimes consist of four, at others of five, and frequently of many more: the corpuscles are of different sizes, according to the number assembled in one group. When collected in a heap, the only motion they have is a kind of revolution or rotatory one. The smaller particles separate from the larger, often dividing into as many portions as there are constituent particles in the group; when separated, they revolve with incredible swiftness. To try whether this was a group of animalcula collected together by chance, or whether this was their natural state, the following experiment was made. A single corpuscle was taken the moment it was separated from the heap, and placed in a glass by itself; it soon increased in size, and when it had attained nearly the same bulk as the group from which it was separated, the surface began to assume a wrinkled appearance, which gradually changed till it became exactly similar to the parent group. This new-formed group was again decomposed, like the preceding one, and in a little time the separated particles became as large as that from which they proceeded. It is found in a variety of infusions.
II. PROTEUS.
Vermis inconspicuus, simplicissimus, pellucidus, mutabilis. An invisible, very simple, pellucid worm, of a variable form.