Tn 
1898-99. | ON THE CYTOLOGY OF NON-NUCLEATED ORGANISMS. 445 
were wholly unaffected by hematoxylin. The colouring matter of the 
cell is disposed in the framework of the vesicles of the peripheral zone 
and not in the fluid filling the vesicles (enchylema). 
Regarding the nature of the central body Biitschli speaks positively. 
It is, he maintains, the homologue of the nucleus of higher forms. 
Zacharias had at first held this view, but withdrew it,’ because he found 
that in the central body, in many Cyanophycez there is no nuclein, and 
that, further, when such cells divide, there may be no nuclein demon- 
strable in them, facts which are quite the reverse of those observed in 
the typical nuclei of other forms. Zacharias admits that in some 
animal and vegetable nuclei nuclein may be absent, and Biitschli points 
out the force of the admission, while he calls attention to the fact that 
the absence of mitotic phenomena is no indication that the central body 
is not a nucleus, for the macro-nuclei of Infusoria do not undergo mitosis, 
but direct division. When the cells of Osczllarie were subjected to 
the action of artificial gastric juice the peripheral layer wholly disap- 
peared in some cases, while, in others, portions only of it remained, but 
the “central body” was preserved, and resembled more markedly a 
nucleus, retaining also its capacity for absorbing hamatoxylin. 
Fischer,” in the year following the publication of Biitschli’s paper, 
attacked the correctness of the methods of that observer, claiming that 
the occurrence of a peripheral layer in the cells of Cyanophycee and 
Bacteria is an artificial production, in fact due to plasmolysis caused by 
the fixing reagents and means used in the preparation of the organisms. 
Fischer's observations were made on a limited number of small bacteria 
and also upon unspecified Oscellariw. In these the reagents employed 
caused the shrinkage of the cell protoplasm from the cell membrane and 
as.the shrinkage was unequal, strands of cytoplasm were left extending 
between the shrunken mass and the cell wall to simulate a peripheral 
layer of vesiculated structure. This condition accounted for Biitschli’s 
results. Fischer denied even the existence of a colourless central body 
in the Cyanophycee. 
Biitschli’s’ answer to Fischer’s objections was that, admitting some 
reagents do produce plasmolysis in vegetable cells, this is by no means 
frequent, and treatment with the reagents which he used, viz., picro-sul- 
phuric acid with or without osmic acid, the chrom-osmic-acetic mixture, 
1 Op. Cit. 
2 ‘Die Plasmolyse der Bakterien,” Berichte der k. sachs., Ges. der Wissensch., Mat.-Phys.  KI., 
1891, Pp. 52. 
3 ‘‘ Untersuchungen iiber mikroskopische Schiume und das Protoplasma,” Leipzig, 1892, p. 75-79. 
