DISTRlBUriOX OF SPOKES AND SEEDS. 30/ 



fur, is generally secured either bv suriaces made adhe>ive bv 

 the stick'\' secretion from ghindiilar hairs, or by the develop- 

 ment of outgrowths in the form of hooks or barbed pri( kles 

 (figs 412, 413, 414, 415 ). A few water animals and wading 

 birds distribute seeds which 

 happen to fall into the mud 

 by the adhesion of this mud 

 to their bodies. 



The fleshy fruits with edible 

 parts are usually colored to 

 attract the notice of the fruit- 

 eating animals. Seeds which 

 escape crushing by the teeth or 

 grinding in tlie gizzard are apt 

 to be in condition to germi- 

 nate when \ oided. The seeds 

 of the mistletoe are sepiarated 

 from the pulp of the berry by 

 the birds which eat them. 



Fig. 414. 



d.- 1 ■ , ,1 1 -n Fig. 414. — A, cluster of fruits of Spanish 



, Sticking to the bill, are needles (S/a'.-«W.,//««,.Aj). /.■, a single 

 •\ rr .1.1, 1 i_ fruit enlarged, slio'^ini: barbed a\%Tis, rep- 



Wlpecl Ott on the branches resenting the caU-x lobes, by which it ad- 

 r . 1 J 1 - lieres to animals. A , natural size ; B, 



of trees, where they germi- magnified 2} diam.-After Kemer. 



Fig. 415. — Fruit of cockle-bur ( XaJithiinu 



nate. .s-/3-;^7;/rt?-//^/;/),hai\'ed, showing two seeds. 



rr^i 1 . ^. c ^ t. ^ the upper of which usually germinates a 



i he adaptation Ot plants to ^ear later than the lower. Natural siie.- 



^ , 1 ^ r .-Vfter Arthur. 



any one ol these agents of 



distribution is likely to l.)e more or less eft'ecti\'e with other 

 agents. For example, the tufts of hairs which increase the 

 buoyancy of the seed in air would be equallv effective 

 should the seed chance to alight upion water, or thev may 

 suffice to entangle the seed in the iur of animals. 



494. Adaptations for germination. — Adaptations for dis- 

 tribution not infrecpienth- also secure ad\'antage in germina- 

 tion. It is important for many seeds that they be anchored 

 to the ground when tliey have once been transported, so that 



