OBSERVED IF HERTFORDSHIRE IF 1885 . 
95 
Dividing the period of observation into- three, the average date 
of the first 20 species, from 22nd January to 20th April, is 7*3 days 
late ; of the next 20, from 26th April to 3rd June, 3*9 ; and of the 
last 20, from 6th June to 26th July, 1*2 ; showing that the state 
of backwardness was much the greatest in the early spring, little 
more than half as much towards the end of spring, and not quite 
one-fifth as much in the early part of summer. 
Taking each 10 species in succession, there is but little difference 
in the state of backwardness for the first three months, but there is 
then a sudden change for the better, each group of 10 species for 
the last three months being very little behind the mean in their 
time of flowering. The average for February is 8*0 days late, for 
March 6*7, for April 6*2, for May 1*5, for June 2T, and for July 0*5. 
Of the 10 species selected to represent February, there is no 
difference in the minor groups into which we usually divide them, 
each group averaging 8 days late. Although the month of January 
had an average temperature, the weather was wet and dull, and to 
this the backward state of vegetation in February seems to be due. 
In February the weather was mild, but very changeable, and still 
wet and dull. At Harpenden “ vegetation was kept healthily back 
by seasonable weather ” in January, and in February “ the weather 
was changeable, and the soil saturated, more from want of sunshine 
and wind than from excess of rain,” and consequently wild flowers 
were shy of coming into bloom. 
Of the species representing March, the 6 flowering within the 
month averaged 8 days late, and the 4 usually flowering in April, 
5 days late. March was a cold and dry month, with a mean tem¬ 
perature lower than that of February, chiefly due to frosty nights, 
the mean minimum or night temperature being 4^° lower than that 
of February, and nearly as low as that of January, thus greatly 
retarding vegetation. At Harpenden “ the fine sunny days of 
March were robbed of their stimulating effect on vegetation by the 
low night temperatures, and most of the wild flowers were several 
days later in blooming than in 1884. Seldom,” adds our observer 
there, “has spring corn been got in under such favourable conditions 
as in the present year.” 
Of the species for April the 4 which usually flower within the 
month averaged 5 days late, and the 6 which usually flower in May 
averaged 7 days late. The first 16 days of April were rather cold, 
the last 14 were very warm, but their temperature would not 
sensibly affect the state of vegetation until some considerable time 
had elapsed. At Harpenden “ April was characterised by genial 
weather, and rarely have the stone-fruited trees presented a more 
beautiful appearance than in this year, many being literally break¬ 
ing down with blossom.” 
The 6 species for May which flower within the month averaged 
1 day early, and the 4 usually flowering within the first three days 
of June averaged 5 days late. Here we see the accelerating effect 
of the warm weather of the latter half of April, and the retarding 
effect of the very cold, dull, and wet weather of May. “ May 
