THE CENTROSOME AND THE BLEPHAROPLAST 



89 



nucleus. At about the time the blepharoplast begins to elongate a 

 limosphere appears in the cytoplasm and takes up a position near the 

 anterior end of the blepharoplast. Here it divides, giving rise to a small 

 apical body that remains visible at the end of the blepharoplast until a 

 comparatively late stage. The remaining portion of the limosphere may 

 be seen lying against the nucleus until the maturity of the spermatozoid 



FIG. 29. Spermatogenesis in Polytrichum. 



A-D, androgones, showing behavior of kinoplasmic plates and kinetosomes (fc) during 

 imitoss. E-G, androcyte mother-cells, showing division of central body. H, telophase 

 of last mitosis; each androcyte has a blepharoplast (6). I-K, stages in the transformation 

 of the androcyte into the spermatozoid: a, apical body; /, limosphere; n, nucleus; p, 

 percnosome. L, mature spermatozoid. X 2535. (After Allen, 1912, 1917.) 



Another body, the percnosome, is also seen in the cytoplasm at certain 

 stages. In the opinion of Allen the limosphere is probably identical with 

 the chromatoider Nebenkorper described by Ikeno in Marchantia, and the 

 percnosome with what M. Wilson (1911) terms the accessory body. The 

 apical body is here described for the first time by Allen. 



Pteridophytes. The early papers dealing with the spermatozoid of 

 pteridophytes, such as those of Buchtien (1887), Campbell (1887), Bela- 



