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Professor Huxley's Darwinism. [February, 
stem of brand new horses and asses, whose progeny were 
sterile inter se ; yet supposing both these novelties neighed, 
or both brayed, another series of experiments would be ne- 
cessary to prove that diversity of voice is not diagnostic of 
special creations alone. Further, since “it matters not one 
whit whether this sterility is universal or whether it exists 
only in a single case ” (“ LeCtures,” p. 146), human language 
is as indictable as mule sterility; yet Prof. Huxley would 
assuredly be reluCtant to join the school of folks who de- 
mand that the orang-outang shall converse with his keeper 
before the dodtrine of our Simian origin shall be conceded 
qualified for other than provisional acceptance ! 
It may be incidentally appended that the mule exhibits 
very much that dilatoriness of reproductive power, so to 
speak, which an evolutionist might anticipate. Female 
mules may cross with the parent horse. In France, some 
years ago, a female mule produced foals two years in suc- 
cession to an Arab sire, “Land and Water” informs me; 
while the view that male mules are impotent is partially 
contradicted by faCts, for the hybrid from an ass and zebra 
has crossed with a mare (“ Variation under Domestication,” 
ih, 16). Nor can the testimony of Aristotle be summarily 
rejected,, since he not merely affirms their fertility with mares, 
but specifies the age known as puberty in our own species' 
and in addition gives the proper name for the progenv 
(“ History of Animals,” Book VI.). 
As Prof. Owen, annotating John Hunter (the dog-wolf 
progeny of a friend of whom re-crossed with a dog), has re- 
marked, this capacity of a hybrid to cross with a pure 
species has not the same import as fertility inter se. The mule 
likewise corroborates the Pallasian do< 5 trine, an extension of 
which, as we have seen, interferes with the “ little rift within 
the lute”; for “ Dureau de la Malle, who has so closely 
studied classical literature, states that in the time of the 
Romans the common mule was produced with more difficulty 
than at the present day ” (“ Variation under Domestication ” 
ii., 88). * 
Finally, if mules were fertile, inter se, the advocate of the 
creation of physiological species could retreat a step or so, 
and insist upon the production of jumarts fertile inter se, a 
JP mart being the reputed offspring of a bull and a mare. 
But I am trespassing beyond the limits of this section— the 
discussion of the sterility desideratum. 
