THE PYRENOID OF ANTHOCEROS 
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Fig. II. A spore mother cell somewhat older, with the plastid filled with many 
small starch grains which seem to have developed from the minute violet-stained 
bodies of Fig. lo. 
Fig. 12. A plastid in the embryonic area of the sporophyte immediately above 
the foot, outside the sporogenous layer. No pyrenoid is visible though the plastid 
is filled with starch grains showing great variation in size. 
Fig. 13. A slightly older plastid from the same region as Fig. 12 which has no 
starch but has scattered stained bodies which may be rudimentary pyrenoid bodies. 
Fig. 14. A chloroplast older than that in Fig. 13 in which a number of minute 
bodies are to be seen in the central region, — probably scattered pyrenoid bodies. 
Fig. 15. A slightly older stage in which the pyrenoid can be identified with 
certainty. 
Fig. 16. A plastid in the upper limits of intercalary growth which has a con- 
spicuous dull red pyrenoid. 
Fig. 17. A chloroplast somewhat older than that shown in Fig. 16, at the upper 
edge of the gametophytic sheath. 
Fig. 18. A large plastid in a gametophytic cell, beginning to divide. 
Fig. 19. A very large plastid of an interior cell of the thallus, with the pyrenoid 
divided but the plastid still undivided. 
Fig. 20. Chloroplast of Reboulia hemispherica lacking starch. 
Figs. 21 and 22. Chloroplasts of Reboulia showing the common form and dis- 
tribution of the starch grains. 
