136 



The blades of two opposite leaves must in a very early stage 

 of development have coalesced and in a further stage of growth 

 at least partly regained their independance, namely the petioles 

 entirely whereas the blades still cohere. 



a. Fig. 17 shows that the leaf on the left has been able to 

 develop its apex normally but the edge not shown on the illu- 

 stration proved incomplete. The leaf on the right is stunted 

 in its apical growth and has consequently become two-topped. 



b. The embryonal coalescence has been much completer 

 giving birth in later periods to tensions which finally entail 

 ruptures. In this specimen the leaves are folded longitudinally 

 and only the apices have grown out free from each other. 

 Also in this specimen one of the leaves is two-topped. 



N.B. In both cases it is the ventral sides which have under- 

 gone symphysis. 



R o s a c e a e. 



Rosa hybrida. 



Coll. Mr. Twysel, in suo horto Buitenzorg, Aug. 1910. 



Two flowers of equal size grown together. 



The flowerstalk bears at the base of the synanthy two leaves 

 almost opposite. 



The thalami coalesced to one wdiole with two longitudinal 

 grooves. 



Sepals: a) four normal and reflex as usual, b) two, belonging 

 to different flowers, grown together at the base, c) one between 

 the two flowers partly green, partly petaloid. The whole is 

 two-topped and consequently equivalent with two sepals. Of 

 these 8 sepals, 5 belong to one flower and 3 to the other. The 

 rest of the flower is normal. 



Leguminosae. 



Crotalaria juncea L. 



Coll. C. A. Backer Jan. 1911. 



Habitat the East Indies. 



