EXPERIMENTS WITH TREE SEEDS. 143 
whether pure or mixed, they may occasion very serious loss to 
the owner. The danger, in fact, lies in the selection or classifica- 
tion that has been made in the nursery, sensible though it 
would at first sight appear to be. Had all been planted out at 
the age of five, whatever the size, the small individuals would 
soon — at least in pure woods— have been suppressed and 
removed, but the final yield would not have been affected, seeing 
that it would have consisted of the originally more vigorous 
trees. But where one plants nothing but naturally feeble 
plants—even though these, through being older, may be of 
normal planting size—one has not the opportunity of select- 
ing naturally strong individuals at the periodic thinnings, so 
that both the intermediate and final returns may be seriously 
reduced. 
It is perhaps worth pointing out that in a seed-bed of ordinary 
density the plants that lag behind in development do so because 
the seeds from which they sprang were of less than average size, 
and not because, with an equal chance to start with, they have 
happened to get the worst of the crowding. No doubt, when a 
feeble plant finds itself amongst vigorous neighbours it tends to 
become relatively still more feeble, but that crowding in itself 
is not the primary cause of debility in certain individuals is 
evident from the results of the experiment just cited. The acorns 
were in all cases placed exactly the same distance apart, so that 
each plant had an equal amount of growing-space. But as small 
plants require less growing-space than large ones, it follows that 
the conditions of growth for the small plants of Plot 6 were 
relatively more favourable than for the larger ones of Plots 5, 3, 
or 4, and yet, in spite of such advantage, the small-sized plants 
have done but little, if anything, to overtake the plants which 
originated in the larger seed. 
An experiment with seeds of three degrees of size was also 
carried out in duplicate in the case of the horse chestnut, and 
furnished results similar to those obtained with acorns. In this 
case the weights for fifty of the seeds were :— 
Large chestnuts, ; 2 Ibs. 8 oz. 
Medium chestnuts, . i ; bows 0k aight 
Small chestnuts, Mohs eich Ge 
