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CHARLES E. ALLEN 
lobing varies greatly. This is shown, for example, by the differences 
in this respect between two species so closely related as Blyttia {Pallavi- 
cinia) decipiens"^ and B. Lyellii.^ 
Figure 2 shows stages in the division of the spore mother cell, as 
seen in sections of fixed material. At the earliest stage here shown 
Fig. 2. Stages in the division of the spore mother cell and spore formation in 
Catharinea angustata. From fixed material. 
(figure 2, A), the cell contains four plastids which are located respec- 
tively in the four lobes of the cell. At this time the plastids seem to 
have the form of curved plates; later they become more rounded but 
by no means spherical; the apparent differences in size and shape 
^Farmer, J. B. Studies in Hepaticae: On Pallavicinia decipiens Mitten. 
Annals of Botany 8: 35-52. 1894. 
^ Moore, A. C. Sporogenesis in Pallavicinia. Bot. Gaz. 40: 81-95. 1905. 
