MAKCH 1908.1 ]\nYAKE.—GAMETOPHYTES ETC. OF CUNNTNOHAMIA. 47 - 



Only one megaspore mother-cell is formed in each ovule and 

 situated about the same level as the point of insertion of the 

 integument (Fig. 5). In this respect Cunninghamia agrees with 

 Taxodium^^ and differs from Cryptomeriap where a group of 

 three or four 

 mother -cells are 

 organized. The 



megaspore mother- 

 cell divides about 

 the time of pollina- 

 tion, i. e. the be- 

 ginning of April. 

 The division com- 

 mences with the 

 synapsis stage and 

 is evidentl3^ the re- 

 duction-division. 



One of the mega- 

 spores, probably 

 the lowest of the 

 row, develops into 

 the female gameto- 

 phyte. The young 

 gametophyte is 

 surrounded by two 

 to four layers of 

 larger cells or 

 tapetum. The 

 similar tapetum- 

 tissue was found 

 in Taxodium by 

 CoKER,^^ while it is reported, by Lawson,"*^ to be absent in 



Fig. 5. Longitudinal section of a young ovule, show- 

 ing the dividing megaspore! mother-cell. — Fig. 6. The 

 same at a later stage, showing the young embryo-sac 

 with ^ew free nuclei; t. tapetum. — Fig. 7. Longitudinal 

 section of a young female prothellium, showing the large 

 central vacuole and the parietal layer of cytoplasm, in 

 which numerous free nuclei are imbedded. x70. 



1) Coker: On the Gametophytes and Embryo of Taxodium. Bot. Gaz. Vol. XXXVI. 

 1903. p. 15. 



2) Lawson: The Gametophytes, Fertilization and Embryo of Cryptomeria japonica. 

 Ann. Bot. Vol. XVIIL 1904. p. 424. 



3) 1. c. p. 17. •*) 1. c. p. 424. 



