ORGANS OF EEPRODrCTIOX. 237 



F?^. 497. Fiff.AdS. 



Fig. 499. 



Fig. 497. Tertioal section of a cell of a yonng anther of the Melon, show- 

 ing its gradual growth and separation into regions, ce. Epidermal cells. 

 ci. Internal cells in progress of absorption by the development of the 



masses of cells, cm, in their interior. Fig. 498. Vertical section of a 



cell of a young anther of the Melon in a more advanced state, ce. Epi- 

 dermal layer constituting the exothecium or outer covering of the 

 anther, ci. The internal parenchymatous cells still further absorbed. 

 The masses of cells, cm, are now distinctly seen to contain pollen ; they 

 are hence called parent or mother cells. These cells are surrounded by 

 a special layer of cells, cl, which ultimately forms the endotheclum. 

 From Maout. 



four (two of which are placed in each half of the anther,) (Jigs. 

 497 and 498). by the formation of as many masses, cm, cm, of 

 large cells, which undergo a particular development to be after- 

 wards described, to produce the pollen ; each of these masses is 

 surrounded by a special layer 

 which ultimately forms the inner 

 lining of the anther, cl. As these 

 aggregations of cells continue to 

 develop they press upon the sur- 

 rounding parenchyma, ci, ci, to a 

 greater or less extent, and thus 

 cause its corresponding absorp- 

 tion. "When the absorption is 

 complete and the two pollen- 

 forming masses of cells in each 

 half of the anther themselves 

 unite, we have an anther formed 

 of two large pollen cavities or 

 cells. If these masses do not 

 unite, a portion of the original 

 celhdar mass remains as a sort 

 of partition between them, and 

 the anther consists of four cells. 

 The different parts of which the 

 anther is composed may be best 



Fig. 499. Transverse section of an un- 

 opened anther of Xeottia picta. 

 From Schleiden. a. Connective, b, 

 B. The two lobes of the anther, a. 

 Vascular bundle of the connective. 

 5. Epidermal layer or exothecium. 

 c. Laver of fibrous cells forming the 

 endothecium. d, d, d, d. The four 

 loculi or cells of the anther. Each 

 lobe is seen to be divided into two 

 loculi by a septum or partition, e, e. 

 The sutures or points where dehis- 

 cence ultimately takes place. 



