262 A. B. MACALLUM. 
many of their characters to the nucleoli of highly developed 
vegetable organisms.! He considers that the central portion 
differs very greatly from a nucleus, but whether it performs 
the functions of the latter he is not prepared to say. 
Biitschli,? whose observations on the structure of bacteria 
have been already referred to, found one type of structure 
prevail in both these and the Cyanophycee. ‘The cytoplasm 
is, according to his view, formed of a faintly stainable peri- 
pheral zone, and of a denser, deeply stainable central portion 
which, in the living Cyanophycee, is always uncoloured. Both 
parts are vesiculated. He found that hematoxylin colours 
the cytoplasm blue, while it gives a red stain to granules 
situated in the central portion, and, in the nodal points of the 
vesiculated structures, more especially of those of the peripheral 
zone. These disappear after subjecting the cells to the action 
of artificial gastric juice, but he nevertheless regards them as 
chromatin elements, and he looks upon the central portion 
as a nucleus. Besides these granules, he found in certain 
Oscillariz, in the extreme peripheral portions of the cell, and 
especially adjacent to the transverse cell walls, others which 
did not stain with hematoxylin, but which exhibited a strong 
affinity for eosin. 
Deinega® could formulate no conclusion in regard to the 
presence or absence of a nucleus in these organisms, and also 
in regard to the nature of the granules, although he is disposed 
to regard the latter as formed of an isomer of starch. These, 
of which he found but one species, stain specially with picro- 
carmine, and dissolve in weak hydrochloric solutions (0°3 per 
cent.). 
Passing over the observations of Zukal,* who appears to 
1 “Ueber die Zellen der Cyanophyceen,”’ ‘ Botanische Zeitung,’ 1890, 
Nos. 1—5. 
2 Op. cit. 
3 « Der gegenwartige Zustand unserer Kenntnisse iiber den Zellinhalt der 
Phycochromaceen,” ‘ Bulletin de la Soc. impér. des Naturalistes de Moscow,’ 
année 1891, p. 431. 
4 “Ueber den Zellinhalt der Schizophyten,” ‘Sitzungsber. der K. Acad. 
der Wiss. Wien,’ 1892, Math.-Nat. Classe, vol. ci, p. 301. 
