216 GENERAL HISTORY OF THE INFUSORIA. 



sarcode-like particles or minute Amcehce. If this be so, some ground may be 

 said to exist for the hyi^othesis of certain naturalists, who esteem the ArceUina, 

 and even the Foraminifera, to be a more advanced stage of existence of the 

 simple naked Amoehina. 



Schneider hints at the possibility of a still greater transformation in the 

 case of his Diffiugia Enchelys. He writes — " A Ehizopod occurred in com- 

 pany with Polytoma (see p. 136), the description of which Avill show how very 

 readily it might be supposed to be produced by a metamorphosis of the latter 

 animal. Unfortunately I cannot confirm tliis supposition, and must confine 

 myself to recording the fact." 



Foraminifera. — It is veiy questionable whether the Many- chambered Rhi- 

 zopods can reproduce themselves by off'shoots after the manner of Amoehina, 

 and MonoiJialamia ; and, in short, nothing certain is known as yet of the 

 modes of propagation of this family. 



A group of figiu'es occurs in Schultze's illustrations of Polystomella (XXI. 

 39) which bear on this point of the possible production of new beings by de- 

 tachment of sarcode matter. The description of the figures informs us that 

 some of the sarcode-globules, separated from the chief mass by pressure, have 

 the tendency and power to thi^ow out from themselves contractile variable 

 processes. They exhibit a finely-granular deHcate semifluid tissue, contain- 

 ing many flat globules and large colom^ed vesicles. Other portions, pressed 

 from the general mass, are almost exclusively composed of colouring-particles, 

 derived from the inmost part of the shell ; such become entirely free, or 

 othermse continue attached by a sort of pedicle. 



In the following examination into the modes of development of Polytlialamia 

 we are greatly indebted to Schultze's valuable monograph. Dujardin men- 

 tions seeing in some TrvMcatulinoi the grouping of the contents of the cham- 

 bers into spherical masses, comparable to the green bodies in Zygnema. 

 Schultze, moreover, encountered, in a deposit of living Foraminifera, along 

 ^¥ith numerous empty shells of Rotalidce, several whoUy or partly filled with 

 black globules, the appearance of which suggested their connexion with the 

 reproductive process. Eepeated observation showed that these globules 

 differed in size, but mostly had the diameter of the siphon intervening be- 

 tween the several chambers, or of that of the opening of the last cell. They 

 occupied either eveiy segment of the shell, when those of the innermost were 

 smaller than those of the outer compartments, or otherwise they occiuTcd in 

 only one or two of the ultimate chambers. Every intermediate condition 

 was met with between these two extremes. The globules were composed of 

 a collection of dark molecular corpuscles not enclosed by a membrane, but 

 proved by pressure to be an aggregation, held together by some sort of 

 delicate tissue. They were unacted on by sulphuric, nitric, and by hydro- 

 chloric acid, and by boiling alkalies. 



The ordinary animal substance coexisted in some of the chambers of an 

 animal when others were occupied by these black balls ; but in such instances 

 no outstretched fibres were seen. These structures must be derived either 

 from without as foreign matters, or otherwise be the result of a metamorphosis 

 of the sarcode matter. The former supposition is discountenanced by their 

 appearance, by their resistance to reagents, and their presence even in the 

 inmost chambers. On the latter supposition they are either the result of 

 decomposition of the substance, or they are physiological products, probably of 

 the transformation of the entire body into germinal masses. The former origin 

 is opposed by the direct observation that such bodies have never been en- 

 countered among Foraminifera in coiu'so of breaking up or of decomposition. 

 As to 'the second mode of origin, they bear an analogy to the germinal 



