T^E GROUPS OF TISSUES, OR TISSUE-SYSTEMS. 47 



Plantain (Plantago major) they may readily be pulled out 

 upon breaking the leaf-stalk. In the leaves of plants. 



Fig. 30.— Transverse section of flbro-vascular bundle of Indian corn, a, 

 side of bundle looking toward the circumference of the stem ; i, side of 

 bundle loolcing toward the centre of the stem ; gf, p, large pitted vessels ; s, 

 spiral vessel : r, ring of an annular vessel ; I, air-cayity formed by the 

 breaking apart of the surrounding cells ; v, v\ latticed cells, or soft bast, a 

 form of sieve-tissue. Magnified 550 times.- . ■ 



where they constitute the framework, they are, by macera- 

 tion, readily separated from the other tissues as a delicate 

 network. In the stems of Indian corn the bundles run 



