77 2 
ON PLANTS IN RELATION TO ANIMALS. 
able geological stratum has been known to produce seeds 
which germinated from the effects of heat and light. 
“ This pretty little plant is so familiar to us all that it 
appears almost like a spontaneous product of the soil, and 
so rapidly and constantly does it spring up, that Withering 
says, f On the soil of our moors in the North of England 
being turned up for the first time and lime applied white 
clover appears in abundance, a circumstance in no way satis¬ 
factorily accounted for, but which is known to take place 
both in Britain and North America. 5 In such situations, 
doubtless, the seed may have lain dormant for a length of 
time, until stimulated into vegetation by the admission of 
moisture and heat. The plant is perennial, and bears its 
dense clusters of white blossoms all the summer. In rich 
soils it grows a foot or two in height, but varies greatly in 
luxuriance according to the situation, and is only an inch 
or less above the surface of the ground, becoming almost 
woven in with the thick short grass that forms the natural 
carpet of our downs and commons. Its chief value in cul¬ 
tivation is as a pasture plant; and so quickly does it grow' 
that Mr. Curtis affirms that a single seedling covered more 
than a square yard of ground in a single summer. 
“ It does not seem to be ascertained when white clover or 
trefoil first became cultivated in this country, but it appears 
to be of late date, for it is not mentioned by Gerarde, 
Parkinson, or Bay, as an agricultural plant in this country, 
nor by any of the waiters of the seventeenth century. 
Gerarde, how r ever, says that f there is a Trefoil of this kind 
which is sowne in fields of the low countries in Italy, and 
divers other places beyond the seas, that come up ranker 
and higher than that wffiich groweth in meadows, and is an 
excellent food for cattell, both to fatten them and cause 
them to give good store of milk/ 
“ Sheep thrive well upon this little plant, and there are 
seldom any moors or meadows where it is not to be found. 
Even in the midst of London fogs and dark December 
weather, we have discovered this little plant of the wayside 
nestling under the shadow of a wall in a city garden wait¬ 
ing for the warm day of spring to beam forth, invigorating 
its tiny leaves, and bringing forth its little white blossoms, 
which are then in unseen preparation. 
“ The common plants of a country are almost universally 
associated with its songs and legends. The Irish names for 
Trifolium repens are shamrock, shamrog, or sea muroge; 
and some botanists claim for it priority as the national 
emblem of Ireland. Some contend for the Oxalis aceto- 
