400 PROP. ALLMAN ON THE RECENT RESEARCHES 



which inhabit the excreta of animals. He regards it as iden- 

 tical with the Difflugia enchelys of Schneider. It has a clear 

 glassy shell destitute of sculpture. 



Its reproduction takes place by the protrusion from the shell- 

 orifice of a mass of protoplasm in which a nucleus makes its 

 appearance independently of that of the parent. The protruded 

 protoplasm soon becomes invested by a delicate shell, and the whole 

 might now be easily mistaken for two individuals in conjugation. 

 At the same time pseudopodia radiate from the common bridge of 

 protoplasm, and finally the two parts separate from one another. 



But Ghlamydophrys is, like Lecythium, a colony-forming rhizo- 

 pod ; and in this case the zooids formed by successive constrictions 

 of the protruded protoplasm remain united to one another so as 

 to form the grape-like clusters with the shell-openings directed 

 towards the common point of union originally observed by 

 Schneider. 



Cienkowski frequently found individuals with two, three, or 

 more nuclei. A similar multinucleate condition occurs in Ar- 

 cella, Actinosphceria, and Nuclearia. The real significance of this 

 character, which has an obvious bearing on the unicellular theory 

 of the Protozoa, is not very evident. It is possibly, as suggested 

 by Cienkowski, the beginning of a zoospore-formation or of 

 fission. 



To the development-cycle of Ghlamydophrys belongs also a rest- 

 ing-state which, as in other cases, appears to be conditioned by the 

 drying up of the locality. AVheu passing into the restiug-state, 

 the entire body escapes from the shell, assumes a spherical shape, 

 and clothes itself with a thick membrane. In the grape-like 

 clusters the resting-state is introduced by all the members of the 

 colony with their common protoplasmic basis becoming fused 

 together and enveloped in a single cyst. 



In the same group of single-chambered Thalamophora is an ele- 

 gant little rhizopod to which Archer, who first described it, gives 

 the name oi Gromia socialis, and which possesses, like Lecythium 

 and GJilamydophrys, the curious habit of becoming united with 

 neighbouring individuals into a common colony by the mutual 

 fusion of the pseudopodia. 



Archer's G. socialis has been further investigated by Hertwig, 

 who has raised it into a new genus under the name oiMicrogromia* . 



In a highly interesting and important memoir he has given us 



* " Ueber Microgromia," Schultze's Arehiv, Band x. Supplement -Heft. 



