FREE BOOKS

Author's List




PREV.   NEXT  
|<   168   169   170   171   172   173   174   175   176   177   178   179   180   181   182   183   184   185   186   187   188   189   190   191   192  
193   194   195   196   197   198   199   200   201   202   203   204   205   206   207   208   209   210   211   212   213   214   215   216   217   >>   >|  
four frilled lips, four tufts of digestive filaments in its stomach, and four brightly coloured reproductive organs. It has eight sense-organs round the margin of its disc, eight branched and eight unbranched radial canals running from the central stomach to a canal round the circumference. The point of giving these details is just this, that every now and then we find a jellyfish with its parts in sixes, fives, or threes, and with a multitude of minor idiosyncrasies. _Even in the well-established jellyfish there is a fountain of change._ Sec. 1 Evolution of Plants It is instructive to look at the various kinds of cabbages, such as cauliflower and Brussels sprouts, kale and curly greens, and remember that they are all scions of the not very promising wild cabbage found on our shores. And are not all the aristocrat apple-trees of our orchards descended from the plebeian crab-apple of the roadside? We know far too little about the precise origin of our cultivated plants, but there is no doubt that after man got a hold of them he took advantage of their variability to establish race after race, say, of rose and chrysanthemum, of potato and cereal. The evolution of cultivated plants is continuing before our eyes, and the creations of Mr. Luther Burbank, such as the stoneless plum and the primus berry, the spineless cactus and the Shasta daisy, are merely striking instances of what is always going on. There is reason to believe that the domestic dog has risen three times, from three distinct ancestors--a wolf, a jackal, and a coyote. So a multiple pedigree must be allowed for in the case of the dog, and the same is true in regard to some other domesticated animals. But the big fact is the great variety of breeds that man has been able to fix, after he once got started with a domesticated type. There are over 200 well-marked breeds of domestic pigeons, and there is very strong evidence that all are descended from the wild rock-dove, just as the numerous kinds of poultry are descended from the jungle-fowl of some parts of India and the Malay Islands. Even more familiar is the way in which man has, so to speak, unpacked the complex fur of the wild rabbit, and established all the numerous colour-varieties which we see among domestic rabbits. And apart from colour-varieties there are long-haired Angoras and quaint lop-eared forms, and many more besides. All this points to evolution going on. The Romance of the Wh
PREV.   NEXT  
|<   168   169   170   171   172   173   174   175   176   177   178   179   180   181   182   183   184   185   186   187   188   189   190   191   192  
193   194   195   196   197   198   199   200   201   202   203   204   205   206   207   208   209   210   211   212   213   214   215   216   217   >>   >|  



Top keywords:
domestic
 

descended

 

established

 

plants

 

cultivated

 

domesticated

 

stomach

 

numerous

 

colour

 

breeds


jellyfish
 

organs

 
evolution
 

varieties

 

instances

 

regard

 

Shasta

 

cactus

 

spineless

 

animals


striking

 
multiple
 

ancestors

 

reason

 
distinct
 

jackal

 

pedigree

 
coyote
 

allowed

 

started


rabbits

 

rabbit

 

unpacked

 

complex

 

haired

 

Angoras

 

points

 

Romance

 

quaint

 
familiar

primus

 
variety
 
marked
 

pigeons

 

Islands

 

jungle

 

poultry

 

strong

 

evidence

 

Evolution