STRUCTURE AND DEVELOPMENT. 



49 



to four) of long whip-like filaments (c). The filaments 

 are divided by transverse septa into about 100 to 

 200 disc-shaped cells, each of which contains an 

 antherozoid. The number of antherozoids produced 

 by a single antheridium has been computed at 20,000 

 to 30,000. The filaments form a dense tangled mass 

 in the centre of the antheridium. 



A careful study of the development of the anthero- 



JPia. 20. — Development of antherozoids (after Guignard). i. Early- 

 stage after nucleus has moved to one side of cell. ii. Later stage 

 showing nucleus extending in both directions along the side of the 

 cell-waU, and two cilia developed, iii. View in situ with cilia curled 

 around rest of antherozoid. iv. Advanced stage, antherozoid having 

 assumed ultimate form and free protoplasm being almost absorbed. 

 V. Free swimming antherozoid. 



zoids has been made by M. Leon Guignard, the results 

 of which are published, together with a series of 

 beautiful illustrations, in the ' Kevue Generale de 

 Botanique,' i, pp. 18-27, t. 2 (1889). It appears 

 that the nucleus of each of the disc-shaped cells in 

 which the antherozoids are formed lies in the first 

 place in the centre of the cell. It soon moves to one 

 VOL. I. 4 



