THE ROCK-IIOSI-: TRIBE. 



73 



very imperfectly divided into cells by short partitions, 

 and so on. 



It must be ob^dous to you, when you come to consider 

 the resemblance of the Rock-Rose Tribe to others, that 

 it has a strongly marked analogy with Poppies (Vol. I. 

 plate 1. p. 19.). They both have crumpled petals, which 

 fall off soon after they expand, a great many stamens 

 growing beneath the ovary, an ovary with parietal pla- 

 centae, and numerous seeds. But, on the other hand, 

 they are separated by many equally remarkable differ- 

 ences, as vou will see bv the following contrast. 



Poppy Tribe. 

 Parts of flower 3 or 4. 

 Calyx in a perfect whorl, and 

 soon falling off". 



Ovules with the foramen next 

 the base. 



Embryo straight and very mi- 

 nute, in a large quantity of 

 albumen. 



Radicle of the embryo next the 

 base of the seed. 



Rock-Rose Tribe. 



Parts of flower 5. 



Calyx in a broken whorl, and 

 remaining on the plant as a 

 protection to the seed-ves.sel. 



Ovules with the foramen at the 

 point. 



Embryo rolled up, filling the in- 

 side of the seed, almost to the 

 exclusion of the albumen. 



Radicle of the embryo at the 

 point of the seed. 



I have just mentioned that the Rock-Rose Tribe 

 has a very extraordinary structure ; let me now 

 explain in what that consists. You have already re- 

 marked that the ovule (^fig. 5.) has a perforation or 

 foramen at its point ; all ovules have such a perfora- 

 tion, but not all in the same place. In most ovules it 

 is next the base, in a few only does it exist at the point, 

 as in the plants before you. The use of the foramen 

 is not a little curious. You are aware that when the 



