RELATIONSHIP OF SPECIES. 259 



seems quite inapplicable to the evoluted and diverse types of 

 extreme species. One appears able to detect, however, even in 

 extreme crosses, features which suggest Mendelian interpretation, 

 such as an assumption of the hybrid of the outward abearance 

 (possibly nothing more) of the male parent. Thus Horse $ 

 Ass ? cross appears about f Horse, while Ass $ Horse ? cross 

 seems, on the other hand, approximately f Ass. 



This is a well-known characteristic, but it is impossible to 

 say what would eventuate if these forms were fertile. As these 

 Mules are quite common, the matter would no doubt have been 

 investigated but for their sterility. This, however, is unimportant, 

 as there appear to be forms showing this tendency which are 

 fertile, such as the hybrid Bears, Zebra-Ass, &c, mentioned 

 above. It would almost appear that the male carries some 

 factor for " form " which is perhaps absent in the female. The 

 matter should be investigated by zoological societies, as mostly 

 possessing the means and opportunities to carry on these 

 experiments. 



Darwin has been criticized for following a false track in 

 advocating the theory of gradual divergence, and it is suggested 

 that, had he known of Mendel's work, he might have altered his 

 opinion. This is mere supposition. 



Even if Darwin gave less heed to mutation than variation, 

 the distinction is not important to my argument : a stair is a 

 gradually ascending (or descending) plane, and our ascent is 

 gradual even if, at intervals, we take two or three steps at a 

 time. 



Darwinism is said to have overshadowed and hidden Men- 

 delism ; the position now appears to be somewhat reversed. 



When one remembers that the evolutionary idea was not 

 wanting in the days of Aristotle and the ancients, and that 

 many of the later discoveries are unconsciously fixed in the mind 

 of the cowherd in the barton, it appears possible that the 

 tendency is to apportion too much credit to later investigators 

 than to those of former times. 



My own deductions may be held to favour surmise to the 

 detriment of systematism. Both tendencies carried to excess 

 are no doubt undesirable. 



While I venture to hope that the examples I have given may 



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