282 MORPHOLOGY. 



arising, according to law, in the axil of a leaf; since several buds 

 may arise, without irregularity, in one axil, that which developes 

 most vigorously is termed the main bud, the others accessory buds 

 (gemma aocillaris primaria and accessoria). 3. Lastly, the ad- 

 ventitious buds (g. adventitice), formed at the end of any (secondary) 

 axis capable of development, arising irregularly on the plant. In 

 all these we distinguish buds continually progressing in develop- 

 ment (g. vegetatione continua) ; from buds whose vegetating activity 

 rests for a time after their development into a bud (g. vegetatione 

 interrupta).* Again, buds are distinguished into those which, in 

 the natural course of vegetation, separate themselves from the 

 parent plant and become independent plants (g. plantiparce), and 

 those which always remain in connection with the parent plant 

 (g. ramiparci). Finally, buds are distinguished according to their 

 contents : there are the flower-buds (g. jftoriparce, alabastrus) ; the 

 leaf-buds (g. foliiparce) ; and mixed-buds (g. mixta). 



The bud is the yet undeveloped rudiment of the elongation of an axis 

 already present, or for the formation of a new axis upon one already 

 existing. Since it is not necessarily in the nature of Phanerogamic 

 plants to bear true leaves, so it is not necessarily in the idea of a bud 

 that it should contain the rudiments of leaves, much less that the rudi- 

 ment of a leaf precedes that of an axial organ ; therefore the youngest 

 condition of a bud is merely one in which no rudiments of leaves exist. 

 I have styled the axillary and adventitious buds ends of an axis capable 

 of development, instead of describing thgm as the axis itself in unde- 

 veloped circumstances, for this seems to me a simpler and more universal 

 definition ; and the first origin of such bud appears to me to take place 

 within the parenchyma, so that that which projects as the visible bud 

 might, with equal right, be considered as the end of a particular mass of 

 cellular tissue. I shall speak of the origin of the axillary and adven- 

 titious buds when I come to the subject of propagation. One peculiarity 

 I must not omit here to mention, namely, the total absence of terminal 

 buds, capable of development, in certain plants. This occurs without 

 exception in the Lemnacece, whose flat stem never forms more than two 

 axillary buds, and has no terminal bud. The same remarkable circum- 

 stance is observable of the stems of Ruscus, developed above ground, 

 where every branch spreads out into a flat leaflike expansion, and 

 terminates in a spine instead of a terminal bud. This holds for the 

 short flower-bearing side branches, as well as for the thin, long, main 

 branches, out of angles of the leaves of which those flower-bearing branches 

 spring. Tiiis must not be confounded with those cases wherein a ter- 

 minal bud is indeed originally presented, but is very frequently abortive, 

 as in Syringa vulgaris ; nor with those where it is always developed as 

 a flower-bud, as in Viscum album. The accessory buds so frequently 

 occurring in the axils of leaves (see Keeper in the Linnsea, vol. i. p. 461.), 

 for instance, in Aristolochia Sipho, Gymnocladus canadensis, &c., cer- 

 tainly merit a more minute investigation of their development ; they 

 may of course often merely represent collectively the secondary axillary 

 and terminal buds of a solitary, the proper primary axillary bud, for 

 instance, certainly in Cornus mascula, Ptelea trifoliata, Salix caprcea, 



* Which Linna?us called hybcrnacvla. 



