"The above-mentioned Phial of Sea Water came safe, and some of the Animalcules were discovered in it, but they did not emit any Light, as my Friend says they do, upon the least Motion of the Phial when the Water is newly taken up. He likewise adds, that at certain Times, if a Stone be thrown into the Sea, near the Shore, the Water will become luminous as far as the Motion reacheth: this chiefly happens when the Sea hath been greatly agitated, or after a Storm." Obviously what Mr. Sparshall, Baker's correspondent, took for a worm was the large flagellum. The chief investigators of this group have been Huxley, Cienkowski, Allman, Bütschli, and G. Pouchet, while Ischikawa and Doflein have elucidated the conjugation. {136}CHAPTER VI PROTOZOA (_CONTINUED_): INFUSORIA (CILIATA AND SUCTORIA) IV. Infusoria. _Complex Protozoa, never holophytic save by symbiosis with plant commensals, never amoeboid, with at some period numerous short cilia, of definite outline, with a double nuclear apparatus consisting of a large meganucleus and a small micronucleus (or several),[149] the latter alone taking part in conjugation (karyogamy), and giving rise after conjugation to the new nuclear apparatus._ The name Infusoria was formerly applied to the majority of the Protozoa, and included even the Rotifers. For the word signifies organisms found in "infusions" of organic materials, including macerations. Such were made with the most varied ingredients, pepper and hay being perhaps the favourites. They were left for varying periods exposed to the air, to allow the organisms to develop therein, and were then examined under the microscope.[150] With the progress of our knowledge, group after group was split off from the old assemblage until only the ciliate or flagellate forms were left. The recognition of the claims of the Flagellates to independent treatment left the group more natural;[151] while it was enlarged by the admission of the Acinetans (_Suctoria_), which had for some time been regarded as a division of the Rhizopoda. {137}I. CILIATA _Infusoria, with a mouth, and cilia by which they move and feed; usually with undulating membranes, membranellae, cirrhi, or some of these._ Genera about 144: 27 exclusively marine, 50 common to both sea and fresh water, 27 parasitic on or in Metazoa, the rest fresh water. Species about 500. We divide the Ciliata thus:[152]— (I.) Mouth habitually closed, opening by retraction of its circular or slit-like margin; cilia uniform Order 1. GYMNOSTOMACEAE. _Lacrymaria_, Ehrb.; _Loxodes_, Ehrb.; _Loxophyllum_, Duj.; _Lionotus_, Wrez.; _Trachelius_, Schrank; _Amphileptus_, Ehrb.; _Actinobolus_, St.; _Didinium_, St.; _Scaphiodon_, St; _Dysteria_, Huxl.; _Coleps_, Nitzsch.; _Dileptus_, Duj.; _Ileonema_, Stokes; _Mesodinium_, St. (II.) Mouth permanently open, usually equipped with one or more undulating membranes, receiving food by ciliary action (TRICHOSTOMATA, Bütschli)