3/8 

 Prkssuri-; of thi: Buds (Bi.astomania A. I'.k.). 



In the preceding section the so-called "sprouting of the stock" lias been 

 considered. The phenomena are observable everywhere where large trunks 

 of poplars, oaks, beeches, chestnuts, etc., have been felled. On the cut sur- 

 face of the stump a callus arises from the cambial zone and numerous ad- 

 ventitious buds are formed on this. The various processes of propagation 

 by "leaf -cuttings" of Begonias, Ciesnerias, etc., show that new buds may be 

 produced on the cut surfaces of herbaceous stems and leaves. The peculi- 

 arity of "viviparity" should be presupposed as equally well-known, i. e., the 

 development of new vegetative buds from an uninjured leaf blade during 

 the normal course of development {Asplenium, Bryophyllurn, etc.). Fre- 

 (|uently observed, but abnormal cases, are similar formations of buds in 

 Cardaminc pratensis, Drosera interynedia, Arabis pumila, etc. Duchartre 

 found small leafy shoots growing out nf leaves of Solamiin Lycopersicum. 

 liraun observed such excessive formation of adventitious buds on the leaves 

 and especially f)n the stems of the cultivated forms of Calliopsis tinctoria. 

 Vox example, he could count about 300 on a piece of stem possibly 20 cm. 

 long'. Similar cases have also been observed on other plants'-, and I found 

 specimens of Pelargonium zonalc and F. peltatum with disc-like, fleshy 

 outgrowths at the base of the stem which were entirely covered with little 

 buds. Individual, more vigorous specimens developed to such a point that 

 even very small leaves could be distinguished; the majority of the buds 

 died because of mutual pressure. A similar fleshy cushion was formed by 

 a Dahlia 7'ariabilis tuber which had been forced in a propagating case, in 

 order to develop new eyes from the base of the stem. The shoots were cut 

 off immediately for use as cuttings, whereupon the growing stumps de- 

 veloped new lateral shoots from their basal buds, which became more and 

 more numerous but increasingly weaker. In this way a herbaceous goitre 

 ipiarl was produced. 



The Goitre Gxarl of Treks. 



\\ ith the rarely occurring bud accumulation in herbaceous plants, 

 abo\e mentioned, there is naturally connected a formation of goitre gnarls 

 in trees, which, with few exceptions, are produced when the growth in 

 length of normal branch buds is prevented, thus inducing the sprouting of 

 new lateral buds in their stead. The shoots from such buds stand closer, 

 the nearer they are to the base of the branch from which they arise, because 

 the internodes are shortest there. I f the tip growth of such shoot primor- 

 dia is limited by injury, or some other cause, such as mutual pressure, they 

 again develop lateral shoots. 



The illustration from a trunk of Acer campestre in Fig. 58 gives a 

 fine example of a goitre gnarl. After the noticeably thick l)ark had been 



1 Braun. A., t)ber abnorme Bildung von Adventivknospen am krautartigen 

 Stengel von Calliopsis tinctoria, Dec. Verh. d. Bot. Ver. d. Frov. Brandenburg, XII, 

 p. 151. 



- Magnus, I'., Verh. d. Rot. Ver. d. Prov. Brandenburg, XII, p. 161. 



