A CRITIC OF NATURAL SELECTION ANSWERED 313 



far the larger number of cases no such explanation is 

 possible, and no other adequate explanation has been sug- 

 gested except variation and Natural Selection. It is, of 

 course, admitted that the action of the environment does 

 produce definite changes in all organisms, more especially 

 in plants, but there is no evidence that such changes are 

 transmitted to the offspring of the individuals in which 

 they have been produced. 



On the other hand, there is direct evidence that many 

 such changes are not transmitted, an example of which is 

 the Arctbis anacJioretica with remarkable tissue-papery 

 leaves, due to its growth in hollows of rocks, where 

 neither sun nor rain reach it. Seeds of this plant when 

 cultivated at Kew produced the common Arahis aljnna. 

 The same thing occurs with many plants, as every cultiva- 

 tor knows ; but other species with no greater peculiarities 

 externally preserve their characters under cultivation, 

 though exposed to the most varied conditions. As we 

 thus know that some variations directly due to the environ- 

 ment are not transmitted, and also know that an immense 

 number of spontaneous or congenital variations arc trans- 

 mitted, since by taking advantage of this fact almost all 

 the improvement in our domestic animals and cultivated 

 plants has been effected ; and yet further, that no case has 

 been found in which such spontaneous variations are wholly 

 intransmissible — the logical conclusion is that the two 

 kinds of variation are distinct in their nature. This view 

 of the subject is adopted by those botanists who are now 

 endeavouring to determine the true nature of the numerous 

 alleged species, sub-species, and varieties of our native 

 plants. They test the fixity of the characters which dis- 

 tinguish each form by cultivation. If these characters 

 remain unchanged, and are transmitted by seed, the form 

 is a permanent one and deserves to be recorded as a species 

 or sub-species ; but if, as frequently occurs with forms 

 which appear quite as distinct as those which are stable, 

 the plant reverts on cultivation to some other forni, it is 

 evidently a modification due to some local conditions of 

 the environment, and should be treated dififerenth'. Mr. 

 Beeby has proposed to call the former " intrinsic," the 



