1911] The Ottawa Naturalist. 17 



about 50 feet by 300 feet in extent, and adjoins the Dominion 

 Observatory. It was started in 1887 on what was then a culti- 

 vated field. The trees were planted mostly three feet apart each 

 way, but have been thinned out considerably since, as individuals 

 fell behind in the struggle for light. Those which remain are 

 now over thirty feet in average height and their tops unite to 

 form a continuous canopy overhead, through which little direct 

 light filters. Natural pruning has kept the trunks comparatively 

 free of large branches, and about five years ago the lower 

 branches were all trimmed off. On the sides of the plantation 

 an untrimmed border of more densely branching Norway Spruce 

 shuts out the light from that quarter and acts as a barrier to the 

 sod. In only one place within, on an area of a few square yards, 

 is there sufficient light to admit of the formation of a sod ; other- 

 wise the conditions are uniformly those of a dense pine forest. 

 The floor has a moist covering of several inches of needles, the 

 soil beneath being a light sandy loam with some gravel. 



To casual observation, vegetation was almost wanting in 

 this area, plants occurring for the most part as isolated individ- 

 uals. Nevertheless as the result of four careful examinations 

 in as many months, forty-five species of fern and flowering 

 plants were recorded, as well as several mushrooms and other 

 fungi. Many of these were merely seedlings or immature plants, 

 but twenty-four were found to be flowering, and in most cases 

 producing seed. Specimens, of the latter were shown, and a 

 tabulated list of all the plants was distributed. It showed that 

 there were represented twenty-five families and thirty-seven 

 genera, no family having more than three representatives, 

 except the Composite?, which had twelve. Twenty-two were 

 indigenous, seven were annuals three winter annuals, five 

 biennials and thirty perennials. 



A 'noteworthy fact about the plants recorded is that almost 

 all are field, not forest plants; and practically none had the 

 appearance of being well established in their present home. 

 This led to the deduction that vegetation had been absent 

 entirely until recently ; probably until the trimming up of the 

 trees five years ago admitted more light and circulating air to 

 the floor of the plantation. An older forest society might be 

 expected to contain a larger proportion of indigenous and true 

 forest plants. Assuming it to be true that this flora is of recent 

 development, we may ask, how has it arisen? Plant migration 

 and adaptability to environment are two factors which would 

 operate together in determining its composition. The former, 

 we may suppose, has been continuously at work; but only when 

 the environment became such that it was tolerable for certain 

 of the plants brought into it, could there be any result. In illus- 



