48 



THEORETICAL DIAGRAMS 



[CH. VI 



90 / Q strength, and then in absolute alcohol, the times 

 varying according to the texture and size of the bud : 

 large buds sometimes need piercing or even cutting to 

 enable the fluids to penetrate. 



The bud is then soaked in xylol until thoroughly 

 impregnated, and finally placed in melted paraffin-wax 

 and kept at about 60 C. until thoroughly interpenetrated. 

 On now mounting the bud, in a solid block of paraffin 

 obtained by cooling, sections can be cut in any direction 

 and sequence and the plan-diagram made by comparing 

 them, additional information being added, obtained from 

 comparison by other methods. 



The extent of information that can be conveyed by 

 properly drawn diagrams is considerable, and may be well 

 seen in Fig. 31, where the relations between the parts of 

 a whole shoot of a Lime, and the incepts of the further 

 shoots in its buds, &c., are expressed in one plan. 



Fig. 31. Lime, Tilia. A inflorescence; a the adherent bract ; b bud; 

 c, d and e bracteoles ; t terminal flower. B plan-diagram of a whole 

 shoot ; axis ; B subtending leaf ; kn bud in axil of leaf 1 ; a bract 

 as in A ; b bud-scale of bud b in A ; a and bud-scales of bud from 

 which the whole shoot sprang; 1 5 order of development of leaves 

 with inflorescences. C plan-diagram of inflorescence, with its bract a, 

 and bud b of A, in axil of leaf L Letters as before, st stipules of the 

 subtending leaf I (Ei). 



