525 



Fig. 162. Section through anterior end of rectum in larva 

 twelve hours before defaecation. Note the malpighian tubes com- 

 mencing to grow out (x500). 



Fig. 163. Section through one of the rectal glands — twenty- 

 one hour pupa (x500). 



Fig. 164. Section along a rectal gland of imago (x800). 



Fig. 165. The same ; onlv the thread-like basal cells repl'e- 

 sented (xloOO). 



Fig. 166. A nucleus from the rectal gland. 



Fig. 167. Epithelium of small intestine of imago (xloOO). 



Fig. 168. Epithelium of rectum of imago (xl500). 



Fig. 169. Section along a lateral interstinal gland of defae- 

 cating larva (x800). 



Fig. 170. Transverse section of tlie same, sixteen hours 

 later, undergoing degeneration (xlOOO'). 



Fig. 171. Portion of dorsal-abdominal gland from four and 

 a half day pupa. In this condition it persists throughout life. 



Plate XXVIII. 



Fig. 172. The same, in fresh pupa (xSOO). 



Fig. 173. Transverse section through tlie anlage of the same 

 on the postero-dorsal region of the midgut, first larval instar 

 (xl200). 



Fig. 174. F^t cell from thirty ^six hour pupa (xBOO). The 

 heavy dots represent tlie basic storage products ; the lighter ones 

 the eosinophilous substances. Eight fat globules are seen. 



Fig. 175. Several oenocytes which have been invaginated 

 from the ectoderm-larva in first instar (xl200). 



, 177. Disintegrating oenocytes — fresh pupa 



Three leucocytes attacking a degenerate oenocyte 

 pupa. 



Oenocyte in the imago (xl200). 

 Female reproductive organs — imago. 

 Termination of left accessorv gland in longitudinal 

 ISO') (x5{X)). 



Portion of right accessory gland (xSOO). 

 One cell from same, to show glandular structure 



The ''lubricating gknd" of ovipositor in section 



Section through left half of body of larva in first 

 instar in region of testis (x500). 



Fig. 186. Structure of testis in first larval instar. Numerous 

 spermatogonia and one supporting cell are seen (xl500). 



Fig. 187. Structure of ovary — defaecating larva. Note some 

 incompletely di^^ded oogonia (xi200). 



Fig. 188. Scent gland of female, opening on bodv surface 

 (xSQO). 



Fig. 189. Section along an ovarian tubule in four and a half 

 day pupa. Note the formation of clusters of nutritive and follicle 

 cells. No ovum is as yet recognizable. Most of the distal cells 

 are in mitosis (xlOOO). 



Fig. 190. Small part of ovarian tubule of imago, showing 

 nutritive cells, follicle cells, ovum, and a polar body (x500). 



Fig. 191. The same (x.350). Note alternate ova and nutri- 

 tive cells. 



Figs 



. 176 



( XlOOO). 





Fig. 



178. 



( X 1000)- 



-fresh 



Fig. 



179. 



Fig. 



180. 



Fig. 



181. 



section (cf. fig 



Fig. 



182. 



Fig. 



183. 



(xl500). 





Fig. 



184. 



(x800). 





Fig. 



185. 



