181 
It is iiotj liovvcvcr, witli tlio imtui'&l clccitli ot species wliich we 
have to do, and our hisk is much more simple, as, in tlie majority 
of the cases we sliall have to deal with, the causes are sufftcicntly 
obvious, and the results almost startling in their rapidity. 
In our own country wo have lost within the historic period, 
according to Mr. Boyd Dawkins, the Droxen which 
inliabited Britain during the time of the Boman occupation, and 
was extirpated probably before the year 1000. The Reindeer 
(proved to have been living in Caithness in 115'J) became extinct 
about the year 1200. The Beaver, Avhich was Imnted for its fur 
oil the banks of the 'Ibivi, in Cardiganshire, during the time of the 
lirst Crusade, was e.xterminated about a.d. 1100 or 1200. The 
last }Volf in Scotland is said to have been destroyed in 1G80, 
whilst in Ireland it survived thirty years later; and the Wild 
Boar became extinct before the reign of Charles I, probably about 
the year 1G20.* All the larger indigenous (piadrupeds would 
probably long since have disappeared from these Islands had they 
not been protected for the sport which they afford. The Wild Cat 
swarm southward and northward in a wild state ; and Azara and Itengger 
have sliown tliat this is caused by the greater number in Paraguay of a 
certain fly which lays its eggs in the navels of these animals when first born. 
The increase of these Hies, numerous as they are, must be habitually checked 
by some means, i>robably by other parasitic insects. Hence, if certain 
insectivorous birds were to decrease in Paraguay, the parasitic insects would 
probably increase ; and this would lessen the number of navel-fre<iuenting 
flies— then cattle and Horses would run wild ; and this would certainly alter 
(as indeed I have observed in parts of South America) the vegetation. This, 
again, would largely affect the insects ; and this, as we have seen in 
Staffordshire, the insectivorous biid.s, and so onwards in ever-increasim^ 
circles of complexity.’ ” ° 
* The Rev. John Storer, in his ‘Wild White Cattle’ (p. 220), calls 
attention to an entry in the ‘ Account Book of the Steward of the Manor of 
Chartley: Preses, Com: Ferrers,’ which runs as follows I6b3— Feb. 
Pd. the Cooper for a palle for ye wild swine, 2s.,” and remarks that the 
entry “ seems to show very clearly that the Wild Boar was not extinct in 
England so eaily as has been supjiosed ; namely, previously to Charles the 
First’s abortive attempt to re-introduce its race into the New Forest.” It 
seems clear, however, from the nature of the entry, that the “wild swine” 
were not self-subsisting, and, therefore, not entirely in a state of nature. 
To what extent and for how long a time they had been under protection 
there is no evidence. 
