BY J. J. FLETCHER AND C. T. MUSSON. 193 



In all three stages, the buds may remain dormant, or they 

 may develop shoots, according to circumstances. In the fifst 

 case, an appropriate stimulus will readily cause shoots to develop. 

 Anomalies, eccentricities, and examples of erratic behaviour are 

 common, and very instructive. 



In addition to the axillary stpm-nodules, unpaired, not de- 

 finitely localised nodules sometimes develop at a lower level than 

 the cotyledons, either on the hypocotyl or on the taproot, of some 

 seedlings. These are very suggestive of wound-infection, and 

 are sometimes obviously pathological. This is particularly the 

 case in most seedlings of two of the Bloodwoods, in which very 

 extensive root-invasion may take place. 



In all these cases, we can find no escape from the conclusion, 

 that the exciting cause of the nodules is attributable to parasitic 

 soil-organisms, probably of the same species, finding vulnerable 

 points for attack under slightly different conditions; and causing 

 the cambium-tissue to proliferate and grow outwards. The 

 nodules are not caused by insects, or other visible parasites. They 

 are outgrowths of proliferating tissue, and not natural growths. 

 They may be a nuisance to the plants, and may temporarily or 

 permanently interfere with the natural growth-habit. More- 

 over, if possible, when opportunity offers, they are brought to a 

 standstill. 



The root-nodules of four young seedlings, of which three are 

 figured, in every case have incorporated the basal portion of a 

 young root. They suggest analogy to what Beyerinck has ob- 

 served in studying the root-nodules of Leguminosse — "'J he 

 splitting of the primary bark for the emission of the side-roots is 

 the special means of entrance of JJ. radicicola^' [Erwin Smith, 

 " Bacterial Diseases," ii., p.l03J. 



The vulnerability of the axils may be due to a weak spot 

 which arises in connection with the differentiation of the buds, 

 or which is exposed about the base of the petioles when the 

 young leaves expand. Until serial, transverse, and superficial, 

 longitudinal sections through the axillary region of series of 

 seedlings have been studied, it is useless to speculate further. 



In the belief that soil-organisms are responsible for the problem 



