THE EMBRYOLOGY OF THE HONEY BEE 



53 





] ( : 





B 



/ m 



Fig. 23. Longitudinal (saggittal) sections, through the anterior region 

 of the germ band, Stage VI, showing segmentation. A is a section along 

 the mid-line, B is laterad of the mid-line. The mesoderm is here now 

 divided into two layers, x 387. 



at the anterior end of the germ band and progresses backward, 

 following the rule for arthropods in general. Figure 22A il- 

 lustrates a median sagittal section of Stage V through that por- 

 tion of the middle plate lying just behind the anterior mesenteron 

 rudiment. Four segments are very plainly visible, much more 

 so than is usual. Figure 22B is taken from the same series and 

 passes laterad of the median plane through one of the lateral 

 plates. It shows very distinctly the segmentation of the future 

 ectoderm, four segments being also represented. The segments 

 are not however always sharply marked off from one another in 

 either the lateral or median plates and are frequently somewhat 

 irregular. 



After the middle plate becomes overlaid by ectoderm its lateral 



