28o 



the morphology of the widely distributed tumours or galls themselves, and which 

 could only have been studied as to causation since the development of the science of 

 bacteriolog}'. 



During the last twenty-five years at the Botanic (lardens. Sydney, and at the 

 auxiliary State Nursery. Campbelltown. I have caused to he raised many thousands 

 of Eucalyptus seedlings for distribution to public institutions. The numlier of species 

 grown at Campbelltown is relatively small, but at Sydney (chiefly for the colour- 

 drawings of seedlings by Miss Flockton for many years, and latterly by Miss Ethel King, 

 an enormous numljer of species, perhaps 150, has l)een grown from time to time; and 

 in many cases these have 1)een kept in pots for years until pronounced mature leaves 

 made their appearance. In course of time, research students will continue or promote 

 the good work of Messrs. Fletcher and Miisson. and I hope that the enormous wealth 

 of nodule material to which T have alluded (and which is far in excess of anv material 

 of the same kind I have ever heard of) will be used for studv. 



The following brief Ijibliography concerning galls in plants other than Eucalyptus 

 may be suggestive. It chiefly refers to the dreaded Crown Gall, which works such 

 devastation in economic plants : — 



Bulletin 213, on '" Crown r4all of Plants; its cause and remedy" (Bureau of 

 Plant Industry. U.S. Dept. Agric. 1911). 



■■ Chemically induced Crown Galls."" In' Erwin F. Smith [Proc. Xat. Acad. Sciences, 

 Washington, iii, 312 (April. 1917) ). " A fuller account, accompanied by photographs 

 and photo-micrographs, will be published in the Journal of Agric. Research." See 

 also Abstract in '" Current Opinion "" (Philadelphia) for March. 1918. p. 193. 



■■ Plant Cancer,"" Missouri Bof. Garden Bull., May, 1919, p. 51. A useful short 

 article, with a few illu.strations and some bibliography. 



In ■■ The Garden" for 12th July, 1873, is a brief article, with a remarkable 

 illustration, on '" Swollen-stemmed Irish Yews."' The specimens, bearing large tuberous 

 bodies between the stem and the proper roots, were obtained from cuttings. The plants 

 were generally under 2 feet in height, while those of normal growth, of the same age, 

 ayeraged about 5 feet ; all, however, having the same healthy appearance. The tnbers 

 averaged from 8 to 12 inches in circumference, with a ligneous structure throughout, 

 but showing large annual rings or growths, and covered with bark, having numerous 

 roots proceeding from the under surface. 



Mr. E. Breakwell, B.A., B.Sc, has very kindly given me a memo., which has 

 been reproduced with little alteration and few additions, in the follou'ing statement. 



BuJbous and tuberous stems may be caused either by (1) insect invas'on, forming 

 galls, (2) fungus invasion, (3) xerophytic conditions, and (4) cpialitative influence of 

 correlation. 



(1) Insecl invasion. See Goebel's '' Organography of Plants, " Part I. Goebel 

 points out that galls are due either to a material excreted from the unfertiU^ed, or 



