454 



BOTANICAL GAZETTE 



[decembter 



Fig. I. Avery young sporocarp showing the beginning of the megasporangium 



and sporocarp wall. 



Fig. 2. A stage later than fig, r. 



Fig. 3. A still later stage; the primary tapetal cells have been cut off in the 

 megasporangium. 



Fig, 4. A considerably later stage; the megasporangium is in the mother-cell 

 stage, but no microsporangial primordia have yet appeared. 



Fig. 5. A little later than fig, 4; the microsporangial primordia are appearing. 



Fig. 6. The microsporangia have begun growth; in the megasporangium 

 the tapetal walls have disappeared. 



Fig. 7, The heterotypic division of the megaspore mother cells; growth in 

 the microsporangium continuing. 



PLATE XXXII 



Fig. 8. A still later stage. 



Fig. 9. A megasporocarp that can be readily recognized as such; micro- 

 sporangia have ceased growth. 



Figs, lo-ij show conditions found in the microsporocarp. 



Fig. 10. A microsporocarp of about the same age as the sporocarp in fig, g; 

 the microsporangia are appearing in large numbers. 



Fig. II, The central portion of an older microsporocarp, showing the micro- 

 sporangium with microspore mother cells, mem. 



fig 



sporocarp, a portion 



megasporangia 



are beginning to grow. 



Fig. 13. An abortive megasporangium 

 upward growth of the cells of the stalk. 



