174 



THE GERM-CELLS 



of the ensuing division-spindle. They seem, however, to have no 

 part in the formation of the mitotic figure or in division, and both 



Fig. 88. Formation of the spermatozoids in the vascular cryptogams, Marsilia (A, Z>,, 

 E-G, BELAJEFF; B, C, O, SHAW), Gymnogramme (H-K, BELAJEFF), and Equisetum (L-N, 

 BELAJEFF). 



A. Primary spermatogonium (two generations before the primary sperm atocytes) in division,, 

 showing centrosomes. B, Primary spermatocyte with pair of " blepharoplastoids " (centrosomes). 

 C, Spindle of primary spermatocyte (first maturation-division). D. Four of the eight secondary 

 spermatocytes with blepharoplast. E-G. Prophase of second maturation-division. H. Pair of 

 spermatids ( Gymnogramme} with blepharoplasts. I-J. Formation of the ciliated band from the 

 blepharoplast. K. Nearly ripe spermatozoid, showing ciliated band (3), nucleus, and " cyto- 

 plasmic vesicle" (the latter is ultimately cast off). L. M. Spermatids of Equisetum. N. Ripe 

 spermatozoid from above, showing spiral ciliated band. O. Ripe spermatozoid of Marsilia with 

 very long spiral ciliated band. 



