•21 



only. Later on this changes; small quantities appear in the 

 three layers of the walls of the pollenchambers (c. tig. 150 

 Pl. XIX). Consequently the alcaloid is here met with in the 

 epiderm also. 



With increasing âge the internai one of thèse three lay- 

 ers dégénérâtes and now the two onter layers alone 

 contain alcaloid (flg. 151. Pl. XIX.) In adult pollenchambers 

 the epiderm alone contains alcaloid (tig. 152 pl. XIX). 

 Archesporinm and tapetnm contain no alcaloid, nor does 

 the adult pollen. 



The gynaeceum contains alcaloid in the parenchyma cells 

 of the pistil (fig. 149 Pl. XIX), the wall of the fruitpri- 

 mordium contains alcaloid also, which alcaloid is for the 

 greater part situated towards the exterior, while the epiderm 

 remains deprived of it. (fig. 155. Pl. XIX, fig. 156 Pl. XX). 



From the very beginning (c. fig. 148. Pl. XVIII) the pla- 

 centa and the internai laver or horny wall of the fruit 

 are deprived of alcaloid. 



This horny layer increases in thickness ont of ail pro- 

 portion to the increase of the other parts so that the per- 

 centage of alcaloid decreases with âge in the fruit. Later 

 on the alcaloid disappears from the parenchyma outside 

 of the horny layer so that the dry fruit contains none or but 

 very little alcaloid. The ovules also are always deprived 

 of alcaloid (c. fig. 155, 15(3, Pl. XIX and XX). The central 

 partition of the fruit contains but very little alcaloid. The 

 peduncle ôf the flower and that of the young fruit contain 

 alcaloid in the parenchyma not in the sieve- tubes ( tig. 155 

 Pl. XIX fig. 150, Pl. XX). 



The iodine solution however précipitâtes in the placenta 

 and in the epidermis of the ovules a substance insoluble 

 in alcohol and consequently no alcaloid (c. fig. 159 Pl. XX). 

 The xanthoprotein-reaction shows it to be a mixture of 

 albuminous substances and some gum (c. fig. 158 Pl. XX). 



