62 DOMESTICATED ANIMALS AND PLANTS 
In respect to room the same principle holds. Plants of the 
same species have a nearly equal rate of growth, so it is a neck- 
and-neck race from start to finish, and often the struggle is so 
nearly equal that they all go down together. It is the case of 
Greek meeting Greek over again. 
The best example of this is the familiar one of overseeding, 
Ofttimes the farmer in finishing his seeding of oats or wheat 
will drive across the end of the field to cover unseeded spots. 
In this way much of the strip thus covered gets a double seed- 
ing. The slender, “spindling” growth of leaf or stem and the 
greatly reduced yield of such places are familiar to all grain 
farmers, as is the general appearance of most fields of ‘‘ sowed 
corn,’’ where so much seed is put on that there is neither room, 
moisture, nor fertility to mature it all, so the total result is a 
weak, stunted growth of all the plants, engaged as they are in 
a mutually destructive competition. 
The fact that a heavier yield of hay and pasture can be pro- 
duced by ground sown to mixed grasses than when sown en- 
tirely to one variety depends partly upon the principle here 
under discussion, and partly, especially with pastures, upon 
the fact that different species take on their best growth at dif- 
ferent seasons of the year, thus lessening by that much the 
direct competition. 
The fiercest battles among animals are not those waged for 
food, which are for the most part exceedingly unequal conflicts. 
They are those waged between the males of the same species, 
‘ which are in almost constant conflict, especially during the 
breeding season, those of different species rarely troubling each 
other except for food. 
Among animals that herd in the wild, like horses, cattle, and 
bisons, one mature male in the prime of life assumes the leader- 
ship of the herd, and he will maintain it as long as he can 
master any younger aspirant that feels he has attained the 
strength and endurance to try conclusions. Some day the success- 
ful aspirant will arise and prevail over the favorite, who will then 
