274 SYNCARPOUS PISTIL. 
arranged upon its inner surface. These modifications of the 
thalamus, together with some others, will be more particularly 
Fic. 604, Fic. 605. Fic. 606. 
Fig. 604. Central part of the flower of the Tulip-tree (Liriodendron tulipifera). 
The thalamus, a, is more or less cylindrical. c¢,c. Carpels. e, e. Stamens. 
Fig. 605. Section of the flower of the Strawberry. The thalamus is nearly 
hemispherical, and bears a number of separate carpels on its upper por- 
tion. Fig. 606. Section of the ripe pistil of the Raspberry, showing the 
conical thalamus, /. 
referred to hereafter under the head of Thalamus (page 292). 
_ These varying conditions of the thalamus necessarily 
Fie. 607. ead to corresponding alterations in the mutual 
relation of the different whorls of carpels which 
compose an apocarpous pistil, and modify very 
materially the appearance of different flowers. 
2. Syncarpous Pistil.—We have already seen, in 
speaking of the floral envelopes and andrcecium, 
that the different parts of which these whorls are 
respectively composed may be distinct from each 
other, or more or less united. From the position 
of the carpels with respect to one another, and 
Fig. 607. Apo- from their nature, they are more frequently united 
carpous PStil than any other parts of the flower. This union 
sant’s - eye may take place either partially, or entirely, and it 
Aden). may commence at the summit, or at the base of the 
carpels. Thus in the former case, as in Xanthoxylon fraxineuwm 
( fig. 608), the carpels are united by their stigmas only ; in Dic- 
tamnus Fraxinella (fig. 624) the upper parts of their styles are 
united ; while in the Labiatie (jig. 609, s), and most Boraginaceze 
(fig. 610, d), the whole of the styles are united. In all the 
above cases the ovaries are distinct ; and in many Boraginacez, 
the stigmas also; but in all Labiatz the stigmas are distinct. 
These examples are to be considered, therefore, as transitional 
states between apocarpous and syncarpous pistils. 
It is far more common to find the carpels united by their 
lower portions or ovaries, and this union may also take place to 
