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BOTANICAL GAZETTE 



3. By the time the embryo sac is mature only a few cells at 

 the apex and base of the nucellus remain. 



4. The primary sporogenous cell gives rise directly to a row 

 of 4 megaspores. The embryo sac is derived from the lowest of 

 these. 



5. An 8-nucleate embryo sac develops in the normal way. 



6. The antipodals usually degenerate early, and when the 

 embryo sac is mature often cannot be distinguished from the 

 nucellus, which also undergoes a certain amount of degeneration. 



7. The embryo sac persists for a long time in the stage when 

 only 5 nuclei are distinguishable. The egg apparatus is normal and 

 the 2 large polar nuclei lie in a mass of granular protoplasm at the 

 base of the embryo sac. 



8. The proembryo is spherical, with a minute suspensor. 



9. In one ovule a 2 -celled structure looking like a young embryo 

 was found at the chalazal end of the embryo sac. 



10. The endosperm develops from the base upward, and is 

 probably accompanied by wall formation. 



11. A few cells at the base of the endosperm are much larger 

 than the rest. They possess hypertrophied nuclei and granular 

 protoplasm. Their function is probably that of passing up food 

 material to the young endosperm and embryo. 



In conclusion I am glad to take this opportunity of thanking 

 Dr. Pearson for suggesting the work and for handing over to me 

 his material and some preparations he had made. I am also 

 indebted to Professor Seward for kind permission to carry on this 

 investigation at the Cambridge Botany School, and to Mr. Gregory 

 for helpful criticism of this paper. I also wish to thank Miss E. L. 

 Stephens, who verified certain points for me in connection with 

 the pollination. 



The Botany School 



Cambridge, England 



LITERATURE CITED 



1. Campbell, D. H., Studies on the Araceae. Ann. Botany 14: i~ 2 5- J 9°°- 



2. , Studies on the Araceae. II. Ann. Botany 17: 665-687- pis- 3°~3 2 - 



