Embryo of Cryptomeria Japonica. 
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The Archegonia. 
The archegonial initials were first observed in material collected about 
May 25, just before the prothallial tissue is thoroughly organized. 
They are always situated at the apex of the prothallium ; and are generally 
peripheral cells, but some were frequently found one or two layers of cells 
below the periphery. They are very easily distinguished from the other 
cells of the prothallium by their large size and deeply staining granular 
cytoplasm. The nucleus is also very conspicuous, being fully twice the 
size of the nuclei of the surrounding sterile cells. A group of the initials is 
shown in Fig. 34. At first the nucleus is centrally situated and the lower 
part of the cell is vacuolated. 
The further development of the archegonium is very rapid and only 
a few preparations showed the most important stages. When they first 
become differentiated, the nucleus is nearly always centrally situated. 
About the time the vacuole develops, the nucleus moves towards the 
periphery of the cell and immediately prepares for division. Several 
preparations showed the spindle, and in each case it was found very near 
the periphery and always parallel with the long axis of the cell. This 
division results in the organization of the central cell and the primary 
neck-cell of the archegonium. A complete wall cuts off the primary neck- 
cell and the central nucleus moves back to a position just above the 
vacuole. From the beginning the primary neck-cell is many times smaller 
than the central cell. 
Very soon after the primary neck-cell has been cut off, the central cell 
enlarges considerably, especially at the base, and the region surrounding 
the vacuole becomes very much wider than the narrow tapering region 
towards the neck. Meantime the cytoplasm becomes very densely granular, 
and the nucleus, which is centrally situated, increases very much in size, 
and the condition of the chromatin shows that the nucleus is preparing for 
further division. 
During the development of the central cell, the primary neck-cell 
undergoes some interesting changes. It does not increase in size, but its 
cytoplasm is densely granular and stains very readily and can therefore be 
easily distinguished from the neighbouring sterile cells. The nucleus now 
very soon divides, and a wall is formed between the daughter-nuclei at 
right angles to the wall which cuts off the primary neck-cell from the 
central cell. Fig. 35 shows the primary neck-cell just after its nucleus has 
divided ; the wall between the daughter-nuclei has not yet been organized. 
The archegonium has now two neck-cells, and these were very easily 
distinguished in longitudinal sections. Indeed longitudinal sections of all 
later stages showed but two cells in the neck. A study of cross-sections, 
however, showed very conclusively that each of the two neck-cells divide 
