974 SUMMARY OF OURBENT RESEARCHES RELATING TO 



the life ebbs. The sexual conjugation of the Ciliates is thus a rejuve- 

 nescence, as Biitschli and Engelmann maintained. It is essential as a 

 reorganization of the nucleus. After a prolonged series of divisions the 

 nucleus undergoes senile degeneration. Without conjugation death would 

 be inevitable. The death is a natural one, the occurrence of which some 

 would deny. Sexual conjugation is the necessary condition of their 

 " eternal youth and immortality." 



New Infusoria.* — Prof. D. S, Kellicott describes four new species of 

 Infusorians : — (1) Podophrya inclinata, spherical in young, pyriform in 

 adult stages ; sub-central spheroidal nucleus ; rarely more than two small, 

 slowly pulsating contractile vacuoles ; few slightly capitate tentacles ; curved 

 pedicel, narrowed towards fixed base ; on swimming feet of Gamharus from 

 Magara river. (2) Podophrya flexilis, sub-spherical, plastic, with many 

 granules in larger specimens ; sub-central, ovoid, granular nucleus ; single, 

 anterior, slowly pulsating contractile vacuole ; two to four, extensile, ap- 

 parently capitate tentacles ; short pedicel ; on pedicels of Epistylis digitalis 

 on Cyclops. (3) Carchesium granulatum, elongate, sub-cylindrical, slightly 

 constricted below thickened peristome border ; rows of cuticular elevations ; 

 moderately elevated, convex, tumid ciliated disc ; long, twisted, longitudinal 

 nucleus ; two contractile vacuoles, slowly and alternately pulsating ; 

 pedicels dichotomously branched without septa ; on Gamharus and plants. 

 (4) Opercularia humilis, fusiform, transversely striated; U-shaped trans- 

 verse nucleus ; low contractile vacuole ; peristome border thickened and 

 slightly dilated ; narrow, convex, moderately elevated lid ; ample cilia ; 

 slightly elevated collar; very short pedicel; on Gammarus and Entomo- 

 straca ; also notes on Lagenophrys discoidea and Gerda sigmoides. 



New Fresh-water Infusoria.f — Dr. A. C. Stokes describes (1) Antho- 

 pTiysa stagnatilis, the colonies of which may consist of more than fifty zooids ; 

 its pedicle does not branch distinctly, the nucleus is placed in the posterior 

 part of the body, and the contractile vesicle is near the centre of the same 

 region. (2) Hexamita gyrans appears to carry the contractile vesicle along 

 the course of its semifluid endoplasm ; this vesicle appears to expand when 

 near the posterior extremity, and to contract and disappear near the antero- 

 lateral border. (3) Ghloromonas pulcherrima has irregular and vacillating 

 movements. (4:) Balanitizoon gyrans executes movements by rapid revolu- 

 tions on its longitudinal axis, with sudden lateral leaps ; it is reproduced 

 both by transverse and longitudinal fission. (5) Gerda vernalis was taken 

 from beneath ice a quarter of an inch thick, but was quite lively. (6) BJiab- 

 dostyla vernalis has a shorter pedicle, and a more posteriorly placed contrac- 

 tile vesicle than It. invaginata Stokes ; it is reproduced by longitudinal 

 fission and by encystment ; the former takes place rapidly, the body widen- 

 ing until the breadth is nearly equal to the length ; it then divides into two 

 longitudinal parts, the half which will finally develope an independent"* 

 pedicle remaining attached to the original foot-stalk by the tip of its pos- 

 terior extremity until it has produced a ciliary girdle, by means of which it 

 swims about freely for a short time. In encystment the animalcules remain 

 quiescent and unchanged for an indefinite and unknown time. (7) B. chse- 

 ticola was found attached to the dorso-lateral setse of Nais. (S) VorticeUa 

 similis has considerable resemblance to F. pattelina MiilL, but dilffers, not 

 only in its fresh-water habitat, but by its striated surfaces, revolute edge to 

 the peristome, and much smaller size. (9) V. vernalis belongs to the group 

 in which the surface is ornamented by cuticular monilations, but is distin- 



* Microscope, vii. (1887) pp. 226-33 (4 figs.). 



t Amer. Mon. Micr. Journ., viii. (1887) pp. 141-7. 



