更多prothallium例句

1. The spore produces the small green prothallium by cell-division in the usual way, and this completes the cycle of fern life.
2. At a later period, other organs are found also on the back of the prothallium.
3. The prothallium is of a peculiar dull-green colour, different from that of the young frond which is subsequently formed.
4. To make these, the prothallium should be placed between small pieces of pith, and the razor must be very sharp.
5. As soon as the fern is firmly established, the prothallium withers away.