562 



PHANEROGAMS. 



is seen in Fig. 388 ; but very commonly the margins of the carpels which turn 

 in as far as the centre then split into two lamellae which are bent back and swell 

 out into placentae in the middle of the loculi, as is shown in Fig. 387. It is clear 

 that in this case the two placentae within each loculus correspond to the margins of 

 the same carpel which forms the outer wall of the loculus. 



Fig. 386.— Gyn.-ieceiim of Saxifra£a cordifoHa ; A longitudinal section, g style, n stigma ; B horizontal section 

 at different heights, / placenta. 



Spurious dissepiments may arise in polycarpellary as in monocarpellary ovaries; 

 if the polycarpellary ovary consists of two loculi, it may thus become quadrilocular, 

 or five original loculi may become divided into ten. The first case is universal in 

 Labiatae and Boragineae. Fig. 390 shows that the ovary is formed of two coherent 

 carpels, the margins of which {I-IV) projecting inwards form a right and a left 

 placenta (//) ; on each of these placentae which correspond to the margins of the 



B 



Fig. 387. — Gynaeceuin ot I'yroia wnbellata ; A longitudinal section, s sepals, ■/> petals, st filaments,/" ovary, it stigma, 

 d nectar-glands ; B horizontal section through the ovary, y the wall, //placentae. 



carpels a posterior and an anterior ovule are produced, but an outgrowth from 

 the mid-rib of the carpel (/F, F/, x) inserts itself between the two ovules be- 

 longing to each loculus, dividing it into two one-seeded lobes. Since at a sub- 

 sequent period the outer part of the wall of each of the four lobes bulges strongly 

 outwards and upwards {E), the separation of the bicarpellary ovary into four 

 separate parts becomes still more distinct ; and finally they completely separate as 



