The effort to make use of the parks to supplement nature-teaching in the schools is also an advance in the right direction, and one that could be followed up with advantage. The trials of the climate of London, and the hurtful fogs, must not be forgotten when criticising. They are no new thing, and gardeners for two hundred years have had to contend with the smoke, and wage war against its effects. But the evil has, of course, become greatly intensified during the last fifty years. Fairchild, the author of the “City Gardener,” in 1722, regrets that plants will not prosper because of the “Sea Coal.” Mirabeau, writing from London in 1784, deplores the fogs in England, and especially “those of London. The prodigious quantity of coal that is consumed, adds to their consistence, prolongs their duration, and eminently contributes to render these vapours more black, and more suffocating--you feel this when rising in the morning. To breathe the fresh morning air is a sort of happiness you cannot enjoy in this immense Capital.” Yet in spite of this gloomy picture there are trees now within the London area, which were getting black when Mirabeau wrote. Smuts are by no means solely responsible for trees dying. There are many other contributory causes. The drainage and want of water is often a serious danger, and bad pruning in the case of the younger trees is another. When branches begin to die, it is a very safe and salutary precaution to lop them off, as has lately been done to such a noticeable extent in Kensington Gardens. But the cutting and pruning of trees by those employed by various municipal bodies is often lamentably performed. The branches are not cut off clean, or to a joint, where fresh twigs will soon sprout and fill in and make good the gaps. Often they are cut leaving a piece of wood, which decays back to the young growth, and rots into the sound part of the tree.