400 SUMMARY OF CURRENT RESEARCHES RELATING TO 



New Commensal Species of Amoebidium.* — Jean L. Ijichtenstein 

 describes A. fasciculatum sp. n., which lives as a commensal in the 

 rectum of Anax imperator (a dragon-fly) in the larval and sub-imagiual 

 stages. He describes curious " bouquet " stages, cylindrical tubes 

 (endoconidia), united in a bundle. From these there arise amoebae which 

 encyst. A fixed uninuclear element forms by nuclear multiplication a 

 small number of stationary endoconidia. As these develop they assume 

 the bouquet arrangement alluded to. The genus Amcehidium has been 

 sometimes referred to Sporozoa ; the author regards it as certain that it 

 should be referred to Protophytes, probably in the vicinity of Eccrinidse. 



Fine Structure of Vorticellid Stalk.f — Salusfcio Alvarado Fernandez 

 gives an account of the minute structure of the stalk in VorticeUa. He 

 distinguishes the external elastic sheath and the internal contractile 

 axis. The latter includes a muscular filament (espasmonema) formed 

 of longitudinal myonemes and a plasmatic cord. The cord is a pro- 

 longation of the cytoplasm of the bell. Filament and cord are enclosed 

 in a membrane continuous with the cortex of the bell. Separating the 

 filament and cord from the membrane there is a fluid. The central 

 cord has an excentric position and a sinuous course. Some preparations 

 show the sheath divided into a series of transverse disks, or septa, which 

 probably have a mechanical function. 



Genus Aspidisca.:]: — Harold H. Plough gives a systematic account 

 of this genus of Hypotrichous Ciliata, with diagnoses of the species 

 and a key. 



New Crithidian.§ — Anna Vivanti describes the structure and life- 

 history of GrUhidia Inflata sp. n. found in the food-canal of Hygrotrechus 

 najas, a water-beetle. The cycle includes pre- flagellate, flagellate, and 

 post-flagellate cliapters. The flagellates are represented by very narrow 

 forms, long delicate forms with a broad region varying in position, and 

 forms enlarged posteriorly, but with a very delicate terminal prolongation. 



In the third, II or post-flagellate, stage the posterior part of tbe 

 organism is somewhat reduced and globular, and the anterior part tends 

 to concentrate towards the nucleus. 



The division of the organism is longitudinal, and affects in order 

 the blepharoplast, the flagellum, the nucleus, and the cytoplasm. The 

 author's results are compared with those of Miss Porter in reference to 

 a species of Crithridia in Gerris pallidum, which seems to be distinct. 



Parasite of Oocytes of Oyster.^ — L. Leger and A. Ch. Hollande 

 have studied a new Protist, which they call Ghytridiopsis ovicola sp. n. 

 They found it in the oocytes of Ostrea edidis in sparse occurrence. It 

 was observed in a vegetative stage with numerous nuclei ; and in state 



* Arch. Zool. Exper., Ivi. (1917\ Notes et Revue, No. 3, pp. 49-62 (7 figs.). 

 t Boll. R. Soc. Espau. Hist. Nat., xvii. (1917) pp. 125-7 (2 figs.). 

 X Trans. Amer. Micr. Soc, xxxv. (1916) pp. 233-44 (15 figs.). 

 § Atti (Rend.) R. Accad Lincei Roma, xxvi. (1917) pp. 132-40 (1 pi.). 

 li Atti (Rend.) R. Accad. Lincei Roma, xxvi. (1917) pp. 174-80 (1 pi.). 

 ^ C.R. Soc. Biol. Paris., Ixxx. (1917) pp. 61-4 (4 figs.). 



