October, the finest of our autumn months, is noted for usually granting the inhabitants of our dripping climate about twenty pleasant sunshiny days, and it is probably on this account somewhat of a favourite with the infusorial world, although the cold of its nights and early mornings thins their numbers, which reach a maximum in the summer heat. Even in the dismal year 1860, October maintained its character, and afforded a great many opportunities of animalcule hunting, during which a constant supply of Stephanoceri were readily obtained, together with swarms of _Stentors_, which are not exceeded in interest by any of the Ciliated Protozoa. The Stentors were abundant on the same weed (_Anacharis_), that formed the residence of the Stephanoceri, and might be seen in large numbers hanging from it like green trumpets, visible to the unassisted eye. In the 'Micrographic Dictionary' they are said to belong to the Vorticella family, which has already given us several beautiful objects, and possess a marvellous power of changing their shape. It is, however, better to follow Stein, who separates them from the Vorticellids and ranges them in his order Heterotricha, as they have two distinct sets of cilia, small ones covering the body and the larger ones round the mouth. Those before us are named after this property _Stentor polymorphus_,[18] or Many-shaped Stentors, and owe their exquisite tint to numberless green vesicles, or small cavities filled with colouring matter like that of plants. This, however, is not essential to the species which may often be found of other hues. In size this Stentor varies from a hundred and twentieth to one twenty-fourth of an inch. It is entirely covered with fine cilia, disposed in longitudinal rows, and round the head is a spiral wreath of larger and very conspicuous cilia leading to the mouth. [18] See Frontispiece.