VI.] STONEWORTS. 45 



small processes of the nodal region, to their complete form. 

 The cells of the filaments are, at first, like any other cells ; 

 but, by degrees, the protoplasm of each becomes changed into 

 a thread-like body, thicker at one end than at the other, 

 and coiled spirally like a corkscrew. From the thin end 

 two long cilia proceed; and, when the cells are burst, and 

 the antherozooids are set free, they are propelled rapidly, 

 with the small end forwards, by the vibration of the cilia. 

 These antherozooids answer to the spermatozoa of animals, 

 and represent the male element of the Char a. 



The sporangia or spore-fruits are borne upon short stalks, 

 the end of which supports a large oval central cell; five 

 spirally disposed sets of cells invest this, an aperture being 

 left between tlie investing cells at the apex of the sporangium. 

 When the antheridia attain maturity they burst, the anther- 

 ozooids are set free, and swarm about in the water. Some 

 of them enter the aperture of the sporangium, and, in all 

 probability, pierce the free summit of the oval central cell, 

 and enter its protoplasm ; but all the steps of this process 

 of impregnation have not been worked out. The result, 

 however, is, that the contents of the central cell become full 

 of starchy and oily matter ; the spiral cells forming its coat 

 acquire a dark colour and hard texture, and the sporangium, 

 detaching itself, falls into the mud. 



After a time, it germinates; a tubular process, like a 

 hypha, protrudes from its open end, and almost immediately 

 gives off a branch, which is the first root (compare the 

 germination of the spore of a fern below). The hypha-like 

 tube elongates, and becomes divided transversely into cells, 

 the protoplasm of which developes chlorophyll. Yery soon, 

 the further growth of this pro-embryo is arrested. But 

 one of the cells, which lies at some distance below the free 

 end of the pro-embryo, undergoes budding, and gives rise to 

 a set of leaves (which are not arranged in a whorl), amidst 



