SEED-DISPERSAL 2961 
(Fig. 257), beggar-ticks 
(Fig. 258), stick seeds, etc.; and 
similar appendages are developed in connection with the 
involucres of cockle-bur 
(Fig. 259, A), burdock 
(Fig. 259, B), ete. 
Fleshy fruits are at- 
tractive as food to cer- 
tain birds and mam- 
mals. Many of the 
seeds (such as those of 
grapes) may be able to 
resist the attacks of the 
digestive fluids and es- 
Fic. 259.—Heads of cockle-bur (A) and burdock 
(B), showing grappling appendages of the 
involucre.—After Kinner. 
cape from the alimentary tract in a condition to germi- 
nate. As if to attract the attention of fruit-eating ani- 
mals, fleshy fruits usually become brightly colored when 
ripe, so that they ‘are plainly seen in contrast with the 
foliage. 
