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ROYAL SOCIETY OF CANADA 



Most of the ericaceous plants on the bog have stems of great length 

 running just beneath the surface, which, as Warming (21. p. 169) points 

 out, is characteristic of bog plants. In one, Mubus Ghamœmoriis, 1 

 followed a stem over seventeen feet without finding an end, and in Ledum 

 and Cassandra for lesser, though considerable distances, also without find- 

 ing the ends. These stems run nearly horizontall}-, branch frequently, 

 and send out roots at intervals. The same stem varies in thickness in 

 different parts ; is now thicker, now thinner, showing a more active 

 growth at some times than at others. It is clear, also, that these stems 

 are now alive onl}- at their tips, the under-moss parts being preserved 

 from decay b}- their position. When one traces what appears to be a 

 clump of young plants of Ledum latifoJium. he often finds that they are 

 all branches of one plant connected beneath the surface, and he cannot 

 find the end of any one of them ; and this is true also of other species. The 

 question now arises, when and how have such plants started, and how do 

 they come to an end ? Since the different branches can grow on con- 

 tinuously, and, making their own roots, become independent of one 

 another and of the original plant, and can grow upwards continuously 

 with the growth of the moss, there seems to be no logical limit to their 

 growth, and no cause for death, such as brings most other woody peren- 

 nials to their end in other situations. Some of them may then be as old 

 as the bog itself, and thus would be amongst the longest lived of phan- 

 erogamic vegetation. Yet a comparison between their age and that of a 

 tree, for example, would not be a fair one ; ]>hysiologically. their lon- 

 gevity should be compared rather with that of those lower organisms, 

 which grow by continuous fission.' This continuous life of the bog plants, 

 however, is pure theory ; its demonstration is attended with great practi- 

 cal difficulties. To some extent this mode of growth is found also in the 

 trees. In the spruces on the islands, on the Lepreau bog, one may 

 observe how the moss is rising and burying them. As it bui"ies the lower 

 branches, these j^ut out new roots, turn upwards at their tips, and grow 

 as independent stems.'- This growth probably, however, does not go on 

 indetinitelj'. since the trees are ultimately overwhelmed and destroved by 

 the moss. 



1 Something similar occnr.s in plants which grow continnonsly from root-stocks 

 in soil, but there is a difference in that the bog is continuously growing and giving 

 support, and a fresli field to the plants on it. The only reference to this continuous 

 growth tliat I have noticed is that in Warming (21, p. 160 and 169), " such as occur 

 on the Sphagnum, must have the power to grow up with the growing surface." I 

 have not been able to see the paper by Miiller, which he there cites. 



- An interesting problem in correlation is here opened up. Does the connecting 

 branch die, removing its growing point from correlation with the parent plant 

 allowing it to become independently apogeotropic, or is it the presence of the moss on 

 its stem which gives the stimulus, changing its diageotropism to apogeotropism ? 



