VII. SCIENCE IN HER CELLS. 139 



the then un progressive shoot becomes collective only, 

 not formative ; and that the pith of the new shoot vir- 

 tually energizes the new wood in its deposition beside 

 the old one. Thus, let a J, Figure 26, be a shoot of the 

 first year, and b c of the second. The pith remains of the 

 same thickness in both, but that of the new shoot is, I 

 suppose, chiefly active in sending down the new wood to 

 thicken the old one, which is collected, however, and 

 fastened by the extending pith-rays below. You see> I 

 have given each shoot four fibres of wood for its own ; 

 then the four fibres of the upper one send out two 

 to thicken the lower : the pith-rays, represented by 

 the white transverse claws, catch and gather all to- 

 gether. Mind, I certify nothing of this to you ; but if 

 this do not happen, let the botanists tell you what 

 does. 



19. Secondly. The wood, represented by these four 

 lines, is to be always remembered as consisting of fibres 

 and vessels ; therefore it is called ; vascular,' a word 

 which you may as well remember (though . rarely needed 

 in familiar English), with its roots, vas, a vase, and vas- 

 culuin, a little vase or phial. ' Yascule ' may sometimes 

 be allowed in botanical descriptions where * cell ' is not 

 clear enough ; thus, at present, we find our botanists 

 calling the pith i cellular' but the wood ' vascular,' with, 

 I think, the implied meaning that a ' vascule,' little or 

 large, is a long thing, and has some liquid in it. while a 

 'cell' is a more or less round thing, and to be supposed 



