48 



THE BOTANICAL 3IAGAZINE, 



[Vol. XXII. Xo. 2.54. 



Cryptomeria. In the first stage of the germination of the 

 megaspore a few free nuclei formed bj^ division of a single 

 megaspore-nucleus are found imbedded in the parietal la^-er of 

 cytoplasm with a large central vacuole (Fig. 6). The growth 

 of the j'oung gametoph^^te is v&rj slow during the first month 



Fig. 8. Longitudinal section of the upper part of a female prothalliuru 

 showing the archegonial complex, a pollen-tiibe with the body-cell and two 

 nuclei above. — Fig. 9. Cross section of the upper part of the archegonial 

 complex, showing 15 archegonia. X 70. 



of its development. The division of the free nuclei goes hand 

 in hand with the enlargement of the protoplasmic sac. At the 

 beginning of June the gametophA^te which is still onh- a proto- 

 plasmic sac with numerous free nuclei attains to a considerable 

 size (Fig. 7). The wall-formation between the nuclei begins 

 about the 10th of June. The subsequent cell-divisions and the 

 filling up of the central vacuole with growing prothallial tissue 

 proceeds rather rapidlJ^ In about a week after the first wall- 

 formation the whole megasporic sac is filled with solid tissue. 

 The process of the prothallium-formation seems to agree prettj^ 

 closely with that of Taxodium as studied by Coker.^^ The 



1' I.e. p. 20. 



