2S5 



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 

 bacteriology. 



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

 auxiliary State Nursery, Campbelltown, I have caused to be raised many thousands 

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

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

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

 an enormous number of species, perhaps 150, has been grown from time to time, and 

 in many cases these have been 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 Musson, and I hope that the enormous wealth 

 of nodule material to which I have alluded (and which is far in excess of any material 

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



The following brief bibliography 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 Gall of Plants; its cause and remedy'* (Bureau of 

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



" Chemically induced Crown Galls," by Erwin F. Smith (Proc. Nat. 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 Bot. Garden Bull.. May, 1919, p. 51. A useful short 

 article, with a few illustrations 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, 

 averaged about 5 feet; all, however, having the same healthy appearance. The tubers 

 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 following statement. 



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

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

 correlation. 



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

 points out that galls are due either to a material excreted from the unfertilised, or 



