MIGRATION 41 



or an impervious, air-containing pericarp. In Ostrya, Pky- 

 salis, Staphylea, the modification is for wind-distribution, 

 while in Carex, Nymphaea, etc., it is for water-transport. 



2. Winged, pterospores {Pterosporae, Trrepov, to, wing). 

 This group includes all winged, margined, and flattened 

 fruits and seeds, such as are found in Acer, Betula, Bumex, 

 many Umhelliferae, Oraminaceae, etc. 



3. Comate, comospores {Gomosporae, KOfxi], ij, the hair of 

 the head). To this group belong those fruits and seeds with 

 long silky hairs, Oossypium, Anemone, Asclepias, etc., and 

 those with straight capillary hairs or bristles not confined 

 to one end, Typha, Salix, etc. 



4. Parachute, petasospores {Petasosporae, ■n-eracro's, ij, sun- 

 shade, umbel). The highly developed members of this 

 group, Taraxacum, Lactuca, and other LiguUUorae are con- 

 nected through Senecio and Eriophorum with the preceding. 

 These represent the highest development of mobility at- 

 tamed by special modification. 



5. Chaffy -pappose, carphospores {Garphosporae. Ka.p<l>oi, to, 

 scale, husk of fruit). In this group are placed those achenea 

 with a more or less scaly or chaffy pappus with slight 

 mobility, as in Budbeckia, Brauneria, Helianthus, etc. 



6. Plumed, lophospores [Lophosporae, A.d</)os, 6, crest, 

 plume). In the fruits of this class, the style is the part 

 usually modified into a long plumose organ, possessing a 

 high degree of mobility as in Pulsatilla, Sieversia and 

 Clematis. 



7. Awned, acospores (Acosporae, d/c^, ij, point). These 

 are almost exclusively grasses, in which the awns serve for 

 distribution by wind, water or animals, and even, according 

 to Kerner, by hygroscopic creeping movements. The 

 mobility in many cases is great. 



8. Spiny, centrospores {Gentrosporae, xei/rpov, t6, spur, 

 spine). This group contains a few representatives which 

 possess a moderate degree of mobility by attachment, as in 

 Tribulus and Genchrus. 



9. Hooked, oncospores {Oncosporae, o'yKos, 6, hook, barb). 

 The members of this group are extremely numerous, and 



