BY T. WHITELEGGE. ' 555 



diameter to the sniallei' diameter of the spore, and others of them 

 about e«iiial to its nucleus. These cells were floating freely in 

 water, anil seemed to have the j^ower of movement. These 

 antheridial cells I will now try to describe, l^he cell-wall is thin, 

 transparent, and devoid of structure, with the exception oi a 

 bracket-like mark, which later becomes a slit, on some part of 

 the wall. The contents of the cell consist of a large numl)er of 

 extremely minute oval, or round, bodies; but a one-sixth object- 

 ive reveals nothing definite, except semi-transparent dots and, 

 when sharply focussed, a thin, dark line. When one of tliese 

 cells is jjlticed in water, osmosis begins, and finally the cell-wall 

 is ruptured at the bracket-like mark, enabling a small cloud of 

 active bodies to escape, and swim rapidly away. When the 

 I'upture takes place, the force is such that there is a kind of 

 backward tlirust, which causes either rotation or chanire of 

 position. The exit-slit appears now to close again, leaving the 

 bulk of these bodies within the cell, where they continue to 

 swim about, vigoi'ously endeavouring to escape. 8ome of them 

 have so difficult an exit that their efforts often cause the cell to 

 move. It takes an hour, and sometimes two hours, for all these 

 bodies to emerge from the cell. There is no rest : they are active 

 all the time; and, after escaping, they scatter rapidly. 



After these bodies had been identified as antherozoids, search 

 \\ as made for some spore in a suitable condition to attract them, 

 but without success. Further observation, however, showed that 

 the ripe spores, taken from an open synangium and placed in 

 water, underwent, in the course of a few hours, a series of 

 changes, by way of cell-division, which revealed the existence of 

 two well-marked kinds of spores, differing from one another, in 

 shape slightly, and greatly in the density of their cellular con- 

 tents: the first indication that the spores were difecious. And 

 it may be said here, though I shall be anticipating a later part 

 of my statement, that the male-producing spores are subreniform 

 in shape, a little wider, or deeper, than the female-bearing spores, 

 with the ends more rounded. Moreover, cell-division in the male 

 spore is definite, and in the female indefinite; in the male, also, 



