232 J. noPKiNsoN — report on phexological 



As shown in the table here given (pp. 230, 231) the time of 

 flowering of 64 species of plants has been observed in the county, 

 out of a total of 71 in the Meteorological Society's list,* two 

 of which moreover ( Car da mine hirsnta and Gentiana campestrisj 

 are rarely met with in Hertfordshire, leaving only five species of 

 frequent occurrence unobserved. 



Of these 64 species we observed 44 at or near Watford, 20 were 

 observed by Mrs. Arnold at Redbourn Bury near St. Albans, 57 

 by Mr. Willis at Harpenden, 4 by Mr. Andrews at Hertford, 32 by 

 Mr. Croft in the neighbourhood of Ware, and 21 by Mr. Fordham 

 at Odsey. 



The earliest dates, in proportion of the number of species ob- 

 served, are those recorded for Watford, then follow Odsey, St. 

 Albans, and Harpenden, very nearly equal, Ware is the next in 

 order, and Hertford the last. 



Comparing this year with the mean of the two previous years, we 

 find that out of 38 species of plants observed in all three years, 25 

 came into flower earlier and 3 later in 1878 than in 1876 and 1877, 

 while 10 flowered at about the same time in all three years. We 

 have before seen that in the state of vegetation generally 1876 and 

 1877 were about eqiud,f and therefore 1878 may be said to be an 

 early year as compared with the mean of the two preceding years 

 and also with either of these years considered separately. 



I have added to the table for 1878 a column showing the mean 

 dates for these three years, which I propose to continue and revise 

 in future reports, so that we may in time arrive at some idea as to 

 the mean dates for the county of the flowering of the plants 

 observed. This column is compiled by taking in each year the 

 earliest date recorded at whatever locality this date may apply to. 

 For instance, in the present table, taking for illustration the first 

 three plants enumerated, for the first the 8th of March is the date 

 adopted, for the second the 21st of February, and for the third the 

 17th of April, these dates being those on which the flowers of the 

 wood anemone, the lesser celandine, and the upright crowfoot 

 respectively were first observed to be open in the county, though 

 not each at the same locality. The dates for the preceding years 

 are similarly taken, and then for each species each day of the 

 month thus arrived at is converted into the day of the year, and 

 this is divided by the number of years of observation, the mean 

 thus found being finally re-converted into the day of the month. 

 This is necessary to be done, because in different years the dates for 

 any species may not occur in the same month of the year. 



Of the 26 species of insects and birds, etc., in the list, 17 have 

 been observed during the year, a considerable increase on the 

 number observed in cither of the two previous years. The record 

 of these observations is now given in the same form as before. 

 The initials used refer to the observers whose names have already 

 been given. 



» ' Trans. Watford Nat. Hist. Soc.,' Vol. I, p. 36. 

 t lb. Vol. II, p. 102. 



