I30 COLIN CLOUT'S CALENDAR. 



from one another, and from all the wild animals inhabit- 

 ing Europe ; and this gives us a false idea to start with 

 of the stability of species. There is no danger of mis- 

 taking a horse for a donkey, or a sheep for a cow. But 

 then we too often forget that these animals are purposely 

 bred as true as possible to an artificial standard ; while 

 all intermediate links with other kinds have been killed 

 off the soil — in civilised countries at least — by the spread 

 of tillage. On the other hand, when, as in the case of 

 rabbits, dogs, and pigeons, we have produced an immense 

 variety of artificial forms, they are generally connected 

 so closely with one another by recent descent that they 

 all breed easily together ; and we forget their differences 

 as lop-ears or blacks, terriers or greyhounds, runts or 

 pouters, in their common points as rabbits, dogs, or 

 pigeons. 



It is not so, however, in the wild life of nature. There, 



though some few species are well marked by the dying 



out of intermediate forms, the difficulty in most cases is 



to find some effective token which will constantly dis- 



dinguish one kind of plant or animal from another. The 



elephant, it is true, now consists only of two obscurely 



marked types, Asiatic and African ; because all the 



others of his race have died off long since : though he 



was once connected by the ancestors of the mammoth 



and the mastodon with a whole line of earlier creatures 



intermediate between tapirs, pigs, and horses. But the 



cat family are still so well represented in our midst that 



you can find somewhere or other every single connecting 



link between our own tame cats and the tiger or the lion ; 



and most of these would probably prove fertile with one 



another, at least along the doubtful border-land. Those 



