304 Carter. — Studies on the Chloroplasts of Desmids. II. 
Figs. 15-18. MPradiata, Hass. Fig. 15, front view of semi-cell showing the bilobed form of 
the chloroplast owing to the shortening of the axis in the median region ; Fig. 17, front view of 
another individual which does not show this phenomenon ; Fig. 16, longitudinal oblique section, 
the ridges cut irregularly in surface section ; Fig. 18, transverse section. 
Figs. 19-22. M. oscitans, Ralfs, var. inucronata, (Dixon) Wille. Fig. 19, front view of individual 
having a distinctly bilobed chloroplast in each semi-cell ; Fig. 20, transverse section showing the 
whole chloroplast distended with stroma starch; Fig. 21, transverse section of an individual whose 
chloroplast contains little starch excepting in the immediate neighbourhood of the pyrenoids ; Fig. 22, 
transverse section of a specimen whose chloroplast is deeply cleft owing to the shortening of the 
axis in the median region. 
Fig. 23. M. Crux-Melitensis, (Ehrenb.) Hass., front view. 
Fig. 24. M. papillifera , Breb., front view. 
Figs. 25-27. M. truncata , (Corda) Breb. Fig. 25, front view of an individual, the axis of whose 
chloroplast is much shortened and very delicate in the median region ; Fig. 26, surface view of the 
polar lobe of J:he same individual seen from the end, showing how the cell-wall is mantled with 
parietal films of chloroplast when the axis is wanting in this region of the cell ; Fig. 27, optical 
transverse section of the basal part of the semi-cell. 
