116 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW, 



provided witli hooks, pi'iekles, prongs, or a sticky 

 exterior. These projections are of various forms, 

 suggesting combs, hair-pins, skewers, barbed arrows, 

 fish-hooks or grappling irons, and they readily become 

 entangled in "vvool, fur, or hair. A rough surface 

 alone, in the case of a small seed, may be suflRcient 

 to attach it to an animal's hide, as in the seeds of 

 Stellaria, Silene, Mont la, etc. 



Appendages of this kind occur only on dry and 

 obscurely coloured fruits, and mostly only on one- 

 seeded portions. Lubbock points out that hooks 

 rarely if ever occur on the seeds or fruits of trees, 

 where they wovild. of course, be beyond the reach of 

 animals. Neither are such appendages at all common 

 on very lowly plants incapable of reaching up to 

 those animals which are of sufficient size to be 

 effective agents in dispei'sion. The bedstraw {Galium 

 Aparine) has its fruit entii-ely beset with small epi- 

 dermal booklets. Equally minute are the booklets 

 on the persistent calyx of the forget-me-not 

 {Myosotis). Hooklets also occur on the fruit of the 

 nightshade {Circcea lutetiana). Each ridge on the 

 fruit of the carrot {Daucns) is surmounted by a 

 comb-like row of recurved teeth. The bur-parsley 

 {Caucalis) and the hedge-parsley (Torilis) have also 

 hooks or bristles on their fruits. The achene of Geum 

 has a single hooked appendage formed from the per- 

 sistent style. Agrimony has its fruit crowned ^vith 

 several rows of hooks. In the Bur-dock the bracts 

 terminate in the hooks \vhich cause the capitula so 

 readily to adhere to one's clothes. The flower heads 

 of the teazle and thistle, on account of their spiny 

 bracts, might also be transported in this way, but 

 they do not readily become detached from the stalk. 

 This in all probability is the purpose of the fimbriate 

 or pectinated margin on the bracts of knapweed 

 (Centaurea). Grass seeds, as everyone knows, readily 

 stick to cloth, fur, wool, etc. This property depends 

 on the shape, roughened sui'face, ciliated glumes, or 

 scabrid awn. The awn of Hordeum is, in fact, a 



