86 J. F. McCLENDON. 



PLATE IV. 



(Pandarus sinitatits Verrill. f'Jgs. 37 JQ, viewed from the vegetal pole.} 



FIG. 37. Shows the metaphase of the first cleavage of the primary ectoblast cell. 

 To the right below is a more highly magnified view of the spindle of the same, in the 

 prophase. g primary germ cell. 



FIG. 38. Shows the prophase of the second cleavage of the entoblast. The blasto- 

 derm is growing over the primary germ cell (,") Some mesoblast cells have been 

 turned under the rim of the blastopore at the sides of the figure. 



FIG. 39. About the same stage as Fig. 38, but the entoblast has not begun its 

 second cleavage and the primary germ cell (g) is in the metaphase of division. 



[In Figs. 40-42 half of the dorsal (animal) side of the egg is shown to the left 

 and half of the ventral (vegetal) side to the right.] 



FIG. 40. Just before closure of the blastopore (6). X= small cell budding into 

 the yolk. An = mesoblastic rudiment of the first antenna. An 2 = mesoblastic rudi- 

 ment of second antenna. Md = mesoblastic rudiment of the mandible. The germ 

 cells are shown (stippled) beneath the ectoderm they have separated from one 

 another. 



FIG. 41. Stage A. Just after closure of the blastopore. The dorsal and ventral 

 ectoderm is omitted save in the anterior and posterior portions, t, M = mesoblast 

 (muscle?) cells, just beneath the ectoderm. The germ cells have divided. 



FIG. 42. Stage A a little later than 41. The eight stippled rods are the spindles 

 of the entoblast. The other stippled areas are mesoblast. 



