7'2 Miscellaneous. 



aud the eiidoplasm for digestion. From the former therefore the 

 pseudopodia originate ; in the latter lie the incepted nutritive 

 materials, and the nucleus is also contained in it. 



Brass * goes still fiirther, distinguishing in the Ehizopod-body, 

 and, indeed, in the Infusoria and the animal-cell generally, four 

 kinds of plasma, namely (proceeding from within outwards) the 

 nutritive plasma, the food-plasma, the respiratory plasma, and the 

 motor plasma. Brass's statements have already been sharply 

 refuted by Biitechli f, and I may therefore here content myself with 

 referring to this memoir, although it relates chiefly to the Infusoria. 

 Biitschli's objections in fact, in my opinion, equally apply 4o the 

 part of Brass's work which relates to the Ilhizopoda. 



Whoever has long busied himself with the study of the Ehizo- 

 poda knows how many species there are, especially among the 

 Amceha', in which, during life, no division into separate zones occurs 

 — in which the whole of the contained bodies, as well as the nucleus 

 and vacuoles, are irregularly whirled about, so that, for example, 

 the nucleus or the nuclei may be at one time pushed to the extreme 

 periphery, and then again llow back into the centre of the body. 

 If in such Ehizopoda, after the application of any reagents, an appa- 

 rent separation into diflerent plasma-layers occurs, this may be 

 definitely regarded as artificially produced, in the face of the con- 

 viction arrived at during the life of the animal. But even during 

 life in many species, especially the tough ones, an apparent division 

 at least into two layers is often to be observed ; this, however, as 

 stated, is only apparent, and is due to the fact that the granules 

 and vacuoles of the plasma group themselves chiefly in the middle 

 of the body, and do not easily make their way into the processes 

 given off ; in reality there is here also only a unitary plasma-mass, 

 and the apparent stratification may disappear at any moment. In 

 the shelled Ehizopoda also a formation of regions frequently occurs, 

 produced in this way: — the granules and nutritive constituents 

 occupy only the anterior or the middle part of the body, and the 

 other parts then stand forth as hyaline zones ; but here also there 

 is no true stratification, for in division, as I have shown $, the 

 whole of the plasma of both divisional halves is completely mixed 

 together. 



I may remark particularly that this conception of the Ehizopod- 

 body does not rest merely ujjon my personal conviction, but that it 

 was expressed long since by, among others, an English student of 

 the Protozoa, Wallich §, and recently demonstrated positively by 

 the most competent authority in this department, Biitschli j|, in 



* ' Die Organisation der tliierischen Zelle,' i. and ii. 



t " BemerliUEgen liber die Schrift des Ilerrn Arnold Brass &c.," in 

 Morphol. Jahib. Bd. xi. 



X " Der Tlieilimgsvorgang bei Euglypha aheolata,'' and " Die Theilung 

 der monothalamen Rhizopoden," in Zeitschr. fiir wiss. Zool. Bd. xxxv. 

 and xxxvi. 



§ Ann. & Mag. Nat. Hist. vols, xi., sii., and xiii. (1868-04). 



II Bronn's 'Klass^cn nnd Ordnungen der Protozoen/ pp. 08, ^9. 



