INTRODUCTION: | TOoNATURAEIS#S 
CALENDAR. 
WILLIAM MARKWICK, who afterwards took the name of Evers- 
field, was an observant Naturalist, and communicated several 
papers relating to British zoology to the Linnean Society, several 
of which appeared in its Transactions. He died in 1813. 
In preparing an ornithological calendar in 1849 we prefaced it 
with the following remarks, which may, with propriety, be reprinted 
heré, as although written for ornithology they will generally apply 
to any department of zoology ; they also allude to the author’s 
favourite subject, migration. 
The importance of the registration of “ feriodic phenomena,” 
appertaining to animals and plants, has been long acknowledged 
and advocated in different periodicals and works, writing of and 
devoted to natural history; and sundry calendars have been 
published, which, although they contain many points worthy of 
observation, and were sometimes very amply made out, were not 
within the reach of all observers, and did not serve as a guide for 
the uniform registration of the phenomena. In our numerous 
works relating to the Ornithology of the British Islands, we have 
many observations and partial lists of the appearance and dis- 
appearance of our winter, summer, and occasional visitants. The 
migrations ; flocking and congregating of species after incubation ; 
disappearance of certain species, and their occurrence again after 
a period of years have been all noted down. Many of our friends 
have kept private notes of these occurrences, and we have ourselves 
made observations over a period of nearly thirty years; but all 
these are neither kept to any plan, nor accompanied with notes of 
the temperature, weather, and other circumstances which would 
have added greatly to their value. They are made in various 
