42 
occur, it were easy to illustrate a floral calendar, for this or 
any other country. How comes this difference about ? Atmo- 
spheric conditions suitable for the regular succession of 
phenomena in one series of plants are not suitable for the 
same order of phenomena in other series. The fact is familiar 
to the most ordinary observer. But the ultimate cause of the 
fact is only to be indicated by a word — adaptation, a quality 
inherent in the individual. Here, in England, with questions 
connected with agricultural industries prominently before the 
public, as of late years they have been, and still are, the 
dependence of these industries upon conditions of the nature 
already indicated is a fact prominently brought to the know- 
ledge of persons and classes concerned. 
18. Neither are we able to indicate, in a manner more 
precise and definite, the actual nature of the determining in- 
fluences to which are due the variation experience demonstrates 
as existing in such phenomena of plant life, as differences in 
growth, luxuriance, fructification, &c. In no two successive 
years are these alike. This quality of fruit grown upon the 
same ground, and as nearly possible under precisely similar 
conditions, varies from year to year ; nor can the most obser- 
vant nurseryman supply a plausible explanation of the circum- 
stance. In India, where from ages the most remote the natives 
have carefully and accurately noted the relation that mani- 
festations of nature bear to each other, the circumstance is 
acknowledged that unusual developments and profuseness of 
inflorescence often precede the recurrence of epidemic disease 
in man. In this country, not only have particular kinds of 
plant disease made their appearance within recent years, but 
their recurrence takes place in relation to season. The disease 
in our most common esculent, the potato, caused immediately 
by the fungus, peronspora infestans, occurs and recurs, as a 
rule, in July and August ; the beet disease,, due also to a 
fungus, occurs sometimes in the winter season. With the 
failure, from seasonal causes, of particular plants, more espe- 
cially those that yield food supplies, disease among animals 
and man follows so regularly that pestilence and famine are 
considered as bearing to each other a relation similar to that 
of effect to its cause. The intimate connexion which exists 
between the conditions of meteorology in a given district and 
productiveness of food-yielding plants has obtained many aud 
very terrible illustrations in our great dependency, India. 
Never, since 1770, has so great a famine befallen that country 
as that which, in 1876-7, extended over the Madras Presidency 
and a considerable portion of the Deccan. The vast importance 
attached to this consideration appears from the circumstance, 
