The Scottish Naturalist. 265 



hooks (e.g., Circcea. Galium aparine or Cleavers, Asperula, 

 Sanicula, &c), which form very efficient grasping organs. In 

 others there is only a ring (or two or three rings) of hooks 

 round the edge below the calyx (e.g., Agrimonia). In the 

 native species of Geufn the styles elongate as the seed ripens. 

 Near its middle there is an abrupt bend. When the seed is 

 ripe the part of the style beyond this breaks away, leaving a 

 sharp hook which, though small, can take a firm grasp. In a 

 few exotic plants the corolla of the flower remains adherent to 

 the top of the carpel, forming sharp, hard hooks as in Tragce- 

 ceros, in which there are two such in the rayflowers. Such a 

 modification of the corolla is not met with in any of our native 

 plants. The flower stalk seldom bears hooks or spines for grasp- 

 ing, but not rarely the bracts are so furnished. In the burdock 

 (Arctium Lappa) each of the narrow bracts that form the invo- 

 lucre ends in a small sharp hook. The whole head breaks away 

 from the stalk, and very readily adheres to the fur or feathers 

 of passing quadrupeds or birds, or to the clothes of passers by. 

 In some Umbelliferce the flowerhead or inflorescence breaks off 

 and becomes attached to passing animals by aid of small spines 

 over the surface of the bracts. In many grasses (e.g., barley) the 

 glumes or bracts end in long prickly awns, which form efficient 

 organs of attachment. 



Fleshy fruits are, as a rule, specially suited for the dispersion 

 of the seeds by quadrupeds, or more generally by birds; and 

 plants with fruits of this kind may frequently be found in situa- 

 tions, such as to show that the seeds must have been brought 

 from a distance. As previously mentioned, the fruits are swal- 

 lowed ; the seeds pass, but little, if at all, the worse, through the 

 intestine, being protected usually in some way by their structure 

 from injury in their passage, and when discharged they germin- 

 ate as readily as, or in some cases even more readily than, if 

 they had never been subjected to this treatment. The seeds 

 suited for this mode of dispersion are frequently protected from 

 injury by being enclosed in a hard covering, which in some is 

 the outer coat of the seed (e.g., nutmeg), while in others it is the 

 inner layer of the carpel (stone of cherry, &c.) Other seeds 

 (e.g., gooseberry) are enclosed in a soft jelly-like pulp, which 

 seems to protect them. 



Few Scottish plants have the seeds themselves exposed, the 

 attraction being found in a fleshy growth, called an aril, that 

 surrounds the seed, and is usually conspicuous in colour ; but 



