192 SUMMARY OF CURRENT RESEARCHES RELATING TO 



times a borer in shells. The huge cup is the free form of a boring 

 sponge. Analogous cases are known, e.g. Gliona celata. Topsent thinks 

 that the sponge should now be called Gliona patera, and that the name 

 Poterion should be suppressed. 



Protozoa. 



Observations on Acinetaria.* — C. H. Martin gives an account of 

 his observations on Acinetaria. He first discusses the " Tinctin-Korper " 

 of Plate, and suggests that under this name chromatin granules which 

 may originate in one of three distinct ways are confused, (1) from the 

 ingested nucleus of the prey ; (2) from the degenerating macro-nucleus 

 after conjugation ; and (3) possibly to a very slight extent in some cases 

 from fragments of the macro-nucleus thrown out in connection with the 

 formation of a digestive ferment. The first of these ways is by far the 

 most common, since conjugating Acinetaria are relatively rare. But 

 these bodies are only distinguishable when the details of the past life of 

 the individual are known, so that the general name is necessary. 



The various stages of conjugation in Acineta papillifera were studied, 

 and the process was found to agree in all essentials with that occurring 

 in the ciliate Infusoria, and that described by Hickson for Dendrocometes 

 paradoxus. It is possible that in those cases in which a fixed form 

 cannot come into contact with another mature individual, a reorganisa- 

 tion of the nuclei may be effected, associated with either (1) conjugation 

 with a free-swimming ciliate bud, or (2) a process of parthenogenesis 

 associated with the formation of the so-called " external buds " of 

 Keppen. 



The second part of the paper deals with the life-cycle of Tachy- 

 blaston ephelotensis g. et sp. n., found by the author in the Bay of Naples 

 in May 1908. In its fully developed stalked form the animal resembles 

 very closely a form which was described many years ago by Robin, and has 

 not since been seen, Acinetopsis vara. The author considers it probable 

 that this form is only a stage in the life-history of Tachyblaston ephelo- 

 tensis. 



In regard to systematic position, Tachyblaston is apparently closely 

 related to Urnulina, and not in any way to the parasitic Sphserophrya 

 described by Metchnikoff. Its position is quite indeterminable from 

 the parasitic stages of its development, but it shows characteristic 

 features in its later, free-living stages. It is of special interest as show- 

 ing the beginning of a complicated life-cycle in association with a 

 parasitic method of life, in a group of Protozoa which are charac- 

 teristically free-living, or at any rate external parasites. Starting from 

 the Acinetopsis form, we have free-living tentaculate buds, which, passing 

 into their host, give rise, by a process of division, to ciliated spores of 

 large size, and these in turn develop on fixation into the Acinetopsis 

 form again. 



New Ciliated Infusorian.j — E. Poyai-koff describes Gepedella 

 hep>atica g. et sp. n., a parasite in the liver of Sphserium corneum, a 



* Quart. Joura. Micr. Sci., liii. (1909) pp. 351-87 (2 pis.). 

 t C.R. Soc. Biol. Paris, lxvi. (1909) pp. 96-7. 



