1903] VEGETATION OF THE BAY OF FUNDY MARSHES 183 
tant result arising from the abundant precipitation in connection 
with the poor drainage, leading to the formation of the immense 
bogs later to be considered. The presence of ground water in 
soil is usually important, but it here plays little or no part, as 
will be pointed out later. Another effect is in the scattering 
of seeds by means of currents. It would seem that the tidal cur- 
rents in the rivers must form efficient disseminators of the seeds 
of at least the salt-plants. I have made a test of this by 
bringing back from the marshes several samples of the newly- 
deposited marsh mud, which the next spring were given very 
favorable conditions for the germination of any seeds in them, 
but no plants appeared. It may be that none were present in 
Summer, and autumn samples might give a different result. 
There is, however, another mechanical effect of the tidal currents 
of considerable importance, namely, although they have built up 
the marshes entirely, they keep the river banks so constantly 
shifting, laying down mud in some places and scouring it out in 
others, that no vegetation is able to gain a foothold below the 
quieter zone near high-tide marks, excepting in the case of the 
curious sedge bogs, which I do not entirely understand; and these 
great banks are bare of all plant life excepting an occasional 
diatom swept from the sea. These banks and flats must be the 
largest areas barren of life in all northeastern America. 
Lemperature—Next in importance to moisture as an ecologi- 
cal factor, is temperature. I have been unable to secure a copy 
January | February} March April May June July 
Mean highest....... 28.2 27.6 34-3 46.4 57-2 4-4 68.8 
Mean lowest ....... 9.0 C57 18.3 30.8 40.4 48.3 ee 
Mean temperature .. 18.6 18.7 26.3 38.6 48.8 ee 61.0 
Mean daily range... 19.2 17.0 16.0 15.6 16.8 16.1 15.6 
Absolute highest....| 50.0] 49:0| 52.0| 71-7] 75.0] 86.7| 88.9 
Absolute lowést..... —~21.0 | —1I5.0 | —I0.0 12.0 27.0 35:0 41.0 
August |September) October November December} Year 
Meaty hinhest 06g Soc 63:8) 63.31 52-8 | 43-3] 32-4] 48-9 
Mean: lowest .<) 6... ona. 9.0.1. 47.8 | 37-6 28.9 15-1 32-7 
Mean temperature .......... 6r.3 1 §§-6) 44.7 | 36.2 23.7 | 40.8 
Mea daily ROS a ey 1§.1 ae 14.2 14.4 17.3; 16.2 
Absolute highest ............ 85.0] 85.0| 72.4| 61.0] 54.5| 88.9 
Absolute lowest............. 43.0 42.5 ai -411-— 1.5 | —19-5 | —21-0 
i a 
