CHAPTEE XXIX. 

 THE GYNCECIUM OF ANGIOSPERMS. 



MATERIALS USED. 



Delphinium Ajacis, just fading; fresh, or in alcohol. Or Helleborm, or 



other similar Ranunculaceous plant. 

 The same of some Liliaceous plant, e.g., Tulip, Hyacinth, Liiium, Hemcro- 



callis. 



The same of a Primula, or a Lysimachia. 

 The same of an CEnotJiera, or Epilobium. 

 Full blown flowers of Aconitum. 

 The same of Monotropa ; preferably fresh. Or of some species of Pyrola f 



or Orchis, or Gloxinia. 

 Orchis species, with swelling ovary, one or two weeks after pollination ; 



fresh ; or flowers of Gloxinia. 

 Torenia asiatica, unpollinised flowers, and those pollinised thirty-six hours 



before ; fresh. 



REAGENTS USED. 



Potash Celloidin Logwood 3 per cent, sugar solution 2 per cent, acetic 

 acid. 



Structure of Monocarpellary Pistil. Let us first obtain a 

 general idea of the structure of the Ovary. For this purpose 

 one of the Ranunculacese is very well suited, e.g., Delphinium 

 Ajacis, the Larkspur of gardens. We choose an old flower, 

 from which the petals and stamens can be easily removed, and ob- 

 serve three pistils (or carpels) left standing in the centre. Even 

 with superficial observation we can distinguish upon the pistil 

 the lower, green, swollen portion the ovary, and the thin part, 

 here rose-coloured, into which the ovary narrows above the 

 Style, This latter ends with the stigma, which in this case is 

 not specially delimited. We now prepare cross-sections through 

 all three ovaries together, and examine them with a low power, or 

 with the addition of a little potash. The cross-section (Fig. 144) 



(394) 



