182 BOTANICAL GAZETTE [SEPTEMBER 
(including the aggressive man). To these should be added 
another of great importance, geography of the basin. 
Water—Of all the factors determining plant form and dis- 
tribution, this is the most important. We consider first the pre- 
cipitation of the marsh country. No records are available for 
the immediate vicinity, but it may be inferred from the amount 
in places surrounding the region. Thus, according to the rain- 
fall map published in 1899 to illustrate the presidential address 
(by T. C. Keefer) before the Royal Society of Canada, the mean 
annual rainfall is: at Moncton, N. B., 44.96; at Truro, N.S., 
43.28; at Charlottetown, P. E.I, 41.45, while at St. John, N.B., it 
is 47.38". The marsh country, lying at the head of the Bay 
of Fundy, and directly in line with it, probably has less rainfall 
than St. John, but more than any of the other localities ; sisi 
hence we may fix it conservatively at 45™. 
As to its distribution through the year, the only available 
records are for St. John, where it is as shown in the following 
table, ‘for a long series of years,” supplied to me by the 
Dominion Meteorological office at Ottawa: 
Jan. | Feb. | Mar,| Apr.| May | June | July | Aug. | Sept.| Oct. | Nov. | Dec. _ Total 
5-55 | 3-93] 3-80] 2.50] 3.66] 2.72| 3.29] 4.64| 3.08] 4.13) 4.71) 5.16 az.1i" 
Diminished pro rata for the lesser total rainfall, this table 
represents proportionally, no doubt, the distribution of precipita- 
tion through the year at the marshes. 
It thus appears that the marshes have a precipitation ample 
for the development of an abundant temperate-region vegetation, 
and that it is distributed fairly evenly through the grew ae sea- 
son of the year. 
As to prevailing humidity of the atmosphere, there are no 
records available even at St. John. But since there is much 
cloudy weather, no little fog and mist, almost insular conditions, 
and very constant southwest winds blowing over the entire’ 
length of the Bay of Fundy, the humidity must be rather high. 
Turning to the influence of water in another way, its mechanical. 
effects, several points are to be noted. One is the very impor- 
