BY .7. .t. FLETCHER AND C. T. MUSSON. 215 



One nodule missing from the first pair, which is chiefly re- 

 sponsible for the basal portion of the encircling tumour, is a 

 fruitful cause of the production of lopsided tumours. An ex- 

 ample is shown in PI. xiv., fig. 3, in which the left nodule of the 

 first pair is missing. Unfortunately the photograph is slightly 

 blurred. A missing nodule from the uppermost pair, may inter- 

 fere with the symmetry of the summit of the tumour. We have 

 a seedling with three incomplete pairs only, one nodule from the 

 top and the bottom pairs on the same side being missing. At 

 the best, all that these could give rise to, is a half-encircling 

 tumour. 



Fig. c of PL viii., appears to be a case in which one nodule of 

 the first pair (on the left) did not develop. The seedling-stem 

 having been broken off, a normal branch in the axil without a 

 nodule then assumed the erect position, and took the place of 

 the seedling stem. The single nodule present, made fair pro- 

 gress. It shows indications of about a dozen shoots, some of 

 them dead. The large shoot, just to the left of the stump of 

 the stem, belongs to the latter. 



Sometimes a nodule, instead of growing downwards and fusing 

 with the stem, will grow downwards and outwards, away from 

 the stem, even in erect seedlings. Three bent seedlings are shown 

 in PL viii. They have stem-encircling tumours, resulting from 

 the fusion of the first pair, which has grown outwards and 

 downwards away from the stem. There is only one pair in fig.a. 

 Figs. 61, 62, show some indication of others poorly developed. 

 There are no incorporated roots in these specimens, nor, we 

 think, was there any likelihood of its happening. In arranging 

 the specimens for being photographed, some of the lateral roots 

 were unintentionally left in unnatural positions. 



Inequality in the comparative rate of growth of the nodules 

 of the same pair, as well as in the comparative growth of suc- 

 cessive pairs, is also a fruitful source of anomalous developments. 

 One nodule of a pair may come to a standstill, while the other 

 goes on growing; or both may progress, but one of them faster 

 than its fellow (as in No.7 of PL vii.). Nodules of the same pair 

 may fuse sooner on one side than on the other; or they may fail 



