Spermatogenesis iu spiders. 573 



All of the following figures are taken from Maevia vittata, gray 

 variety. Figs. 20, 25 and 33 are photomicrographs which have been 

 drawn over. 



Fig. 20. ,,Rest period" showing the single nucleolus resulting from 



the fusion of the two smaller bodies. 



Fig. 21. Same as above. 



Fig. 22. Name as above except that the presence of ctetosomes has 

 given an irregular shape to the nucleolus. 



Fig. 23. Same as above. 



Fig. 24. Later stage showing chromatin knots. 



Fig. 25. Still later stage. 



Fig. 26, Leptotene stage. 



Fig. 27. Same as above. 



Fig. 28. Leptotene stage showing the beginning of the synaptic 

 contraction. 



Fig. 29. Pachytene stage. 



Fig. 30. Same except it shows the presence of small body in 

 nucleus. 



Fig. 31. Diplotene stage. 



Fig. 32. Very early prophase. 



Fig. 33. Side view of first maturation spindle. 



Fig. 34. Same showing quadripartite form of accessory chromosome. 



Fig. 35. Equatorial view of first division showing the presence of 

 ctetosomes. 



Plate 3L 



Figs. 36 to 48 are taken from Maevia vittata, gray variety. 

 Figs. 45 to 48 made from microphotographs drawn over with pen. 2500 : 1. 



Fig. 36. Equatorial view of first division showing simple two rod 

 condition of the accessory chromosome. 



Fig. 37. Same showing unequal size of accessory elements. 



Fig. 38. Showing precocious division of one autosome. 



Fig. 39. Telophase of first division. 



Fig. 40. ,, Resting stage" of the young secondary spermatocytes. 



Fig. 41. Second division spindle, with accessory chromosome. 



Fig. 42. Equatorial view of same. 



Fig. 43. Second division spindle, without accessory chromosome. 



Fig. 44. Equatorial view of same. 



Fig. 45. Spermatids which lack the accessory chromosome. 



Fig. 46. Spermatids which carry the accessory chromosome. 

 Zool. Jahrb. XXXVIII. Abt. f. Anat. 38 



