1905.] NATURAL SCIENCES OF PHILADELPHIA. 205 



Fig. 40. — Pole view of chromosome plate of the spermatid. 



Figs. 41-65. — Lycosa insopita Montg. 



Fig. 41. — Pole view of spermatogonium, monaster stage. 



Figs. 42-44. — Lateral views of synapsis stages. 



Fig. 44bis. — A and B each represent a bivalent and longitudinally split 



heterochromosome of the synapsis stage, and the curved line near 



each an arc of the nuclear membrane. 

 Figs. 45, 46. — Lateral views of nuclei, postsynapsis. 

 Figs. 47-49. — Nuclei in early prophases of first maturation mitosis. 

 Figs. 50-52. — Nuclei in later prophases. 



Figs. 53, 54. — Pole views of monaster, first maturation mitosis. 

 Figs. 55-58. — Lateral views of the same stage. 

 Fig. 59. — Anaphase of first maturation mitosis. 



Figs. 60-63. — Pole views of the chromosome plates of second spermatocytes. 

 Figs. 64, 65. — Lateral views of second maturation spindle; 65 oblique so as 



to show only one spindle pole. 



Postscript. 



Some time after the preceding was sent to press the following papers were 

 received, all confirmatory of my views upon chromosomal conjugation and reduc- 

 tion: L. B. Wallace, "the Spermatogenesis of the Spider," Biol. Bull, 8, 1905; 

 L. T. Dublin, "The History of the Germ Cells in PediceUina americana," Ann. 

 New York Acad. Sci., 16, 1905; and J. B. Farmer and J. E. S. Moore, "On the 

 Maiotic Phase (Reduction Divisions) in Animals and Plants," Quart. Jour. Micr . 

 Sci., 48, 1905. Dublin's paper is of particular importance, because he finds 

 perfect agreement in botli ovogenesis and spermatogenesis. Miss Wallace finds 

 that the accessory chromosomes do not divide in either maturation mitosis; 

 and believes that only that fourth of the spermatids which receives them become 

 functional spermatozoa, so that the remaining three-fourths "are regarded as 

 homologous to the polar bodies thrown off by the ovum." 



