POSITIVE DEDOUl^LEMBNT. 95 



In the filbert or hazel {Corylus Avellana) three 

 carpels are developed in the flower. Normally, 

 however, as the fruit matures, two of these become 

 abortive, so that the ordinary nut consists of a single 

 carpel. Now and again a nut appears which is con- 



FiG. 104. — Crocus sp. Diagram of flower with the formula 

 K3 04A3( + 0)G4. 



siderably larger than usual and whose trilobed contour 

 shows it to be composed of the original three carpels 

 of the flower all equally or sub-equally developed 

 (fig. 105). 



Tbe adhering disks of the tendril of the grape-vine 



Fig. 105. — Corylus Avellana (Hazel). Fruit witli three almost equally- 

 developed carpels. Transverse section. 



(Vitis) are probably the modified swollen tips of the 

 pedicels of the inflorescence ; occasionally they revert 

 to the original condition and produce a grape. This 

 is one of the facts which prove the vine-tendril to be a 

 modified inflorescence. It must therefore be due to the 

 reappearance of floral members (carpels) which have 

 been completely suppressed (PL XXXVIIT, fig. 4). 



