The Structure of the Cytoplasm in the Cells of 
Alicularia scalaris, Cord. 
BY 
M. F. RIVETT, B.Sc. ' 
With Plate VI and three Figures in the Text. 
T HE tissues of the foliose liverwort Alicularia scalaris show, in common 
with many of the Hepaticae, the development of oil-bodies ; they are 
more conspicuous in this particular genus by virtue of their extremely large 
dimensions and high refractive index. The oil-bodies of the Hepaticae 
have been described by systematists as an aid to the identification of 
species; they have been investigated in greater detail by Pfeifer (1), 
Wakker (2), Zimmermann (3), Raciborski (4), von Kiister (5), Garjeanne (6), 
and the results of these investigations have been shortly summarized in 
biochemical works such as those of Czapek ( 7 ) and Molisch. Since, 
however, there still remain some doubts and contradictions in these results, 
particularly in connexion with the origin of the oil-bodies and their relation 
to the cytoplasm, this further research into the subject was undertaken. 
The appearance of the living cells in the fresh mature leaves of 
Alicularia scalaris has frequently been described ; their shape is hexagonal, 
with rounded angles; the walls slightly thickened ; their size is between 
35 /x and 30 ijl ; the chlorophyll granules are large and dispersed regularly 
and closely round the cell-walls ; the large oil-bodies, two, three, or four in 
number (but occasionally more numerous), are suspended in the midst of the 
cell and occupy the greater part of the cavity; the nucleus is not visible in 
the living cell (see Text-fig. 1). 
In a young living leaf, such as the second or third from the growing 
point, mounted and examined in water, the cells are seen to be very much 
smaller, about 7 \x or 8 /x in diameter. In the extreme apical and basal cells 
there is no trace of the oil-bodies, though there are minute refractive 
granules which appear at first to be of similar material (see PI. VI, Fig. 1). 
They are continually in motion, revolving and rotating in the substance of the 
protoplasm. These, however, are found to persist unchanged throughout 
the development of the cell; they never have any close association with the 
developing oil-bodies, and contrast with them in their behaviour towards 
fixing and staining reagents. 
[Annals of Botany, Vol. XXXII. No, C XXV/. April, 1918.3 
