376 
Notes. 
and the thorn might readily have been derived from such an out- 
growth. But the following facts prove that the thorns are accessory 
branches : 
Fig. 2. 
(i) The thorn may dev elope into a shoot and bear leaves. The 
thorn may become either a ‘ long shoot/ or a { dwarf shoot f 
terminating in a flower. Fig. 2 shows a thorn converted into a 
shoot and ending in a fruit. The ordinary axillary bud may 
develope as well; in one case I saw two superposed thorns 
changed into branches, as is shown in Fig. 3 in which t' . br. re- 
