BY J. J. FLETCHER AXD C. T. MUSSON. 209 



In seedlings of some species and in some individuals of the 

 same species, the axillary stem-nodules appear sooner, and pro- 

 gress faster, than is the case in others, or the period of incuba- 

 tion is shorter Sometimes this may be due, in some degree, to 

 unfavourable conditions; but in other cases it seems to be a con- 

 stitutional matter. Hence, it is possible to distinguish between 

 susceptible, and resistant or refractory species, or individuals. 

 The majority of the species whose seedlings are known to us, are 

 susceptible, some more so than others The best examples of 

 refractory species that we have met with are E. robusta and E. 

 lo7i(/i/olia, of both of which we have seen nursery-seedlings in 

 quantity; but we have been unable to get bush-seedlings. Ad- 

 vanced seedlings of these two species are shown in Plates ix and 

 X. The seedling of E. robusta, with eight pairs, (Plate x., fig. a) 

 is the most remarkable refractory seedling we have seen. 



Axillary nodules develop not only on the stems of seedlings, 

 but also on tumour-shoots, showing that the first few leaf-axils 

 of tumour shoots repeat the conditions («ffered by the early axils 

 of seedling-stems. Fig.3 (not numbered) of PI. vi., shows the 

 tumour of a seedling of E. resini/era, whose stem, with one pair 

 of unincorporated nodules, and any shoots that may have been 

 present, was scorched and killed b}- a bush-fire. Two tumour- 

 shoots, as is usual in such a case if the seedling stem is centrally 

 situated, replaced the stem; these were about 7 and 10 inches 

 high, and were doing well when the specimen was taken. Both 

 have the first pair fused with the tumour. The larger has a 

 second pair, unfused, and unequally developed. The smaller has 

 a second pair, one only of a third pair, a fourth pair, and also a 

 fifth pair. [The numbers on the Plate indicate only the con- 

 spicuous ones; the fifth pair of the smaller one, not being very 

 well shown in the photo, was not numbered]. The tumour itself 

 may represent probably three fused and concresced pairs. 



Another ca.se is shown in fig. 2 of PI xii. This also is a case 

 of two tumour-shoots taking the place of a seedling stem after 

 injury, not by fire in this case. Each of them has three pairs of 

 axillary nodules. 



Still another case is illustrated in PI. xviii. The large tumour- 



