no. 
certain very narrow limits. That Nature presents everywhere certain barriers 
which all man’s power of reasoning and all his skill in selection will not 
enable him to pass. That it is a fact, if we take animals of two different 
species, that these species will produce a progeny, if the two species who are 
the progenitors are not remotely separated from each other in their general 
structure. The mules, however, thus produced are sterile and incapable of 
propagating their species. Now this indisputable fact Mr. Warington tells 
me I am not allowed to make use of in refuting Mr. Darwin’s hypothesis, 
because that hypothesis, if true, calls that fact in question. But I maintain, 
in all strictness of philosophical investigation, this fact, if it be a fact, cannot 
be ignored. That the supporters of Darwinism are bound, as the very first 
step to the admission of their theory as a credible account of the origin of 
species, to show that no such limitation as this exists in nature. Mr. Darwin 
refers to the pigeon. He shows the wondrous changes that man can produce 
in the breeding of that bird, all which we readily admit ; no one has denied 
it, and its admission is nothing new. Man, watching with great care certain 
peculiarities in two pigeons, and pairing these, making a similar selection 
among their descendants, and so on, produces a great variety of pigeons, 
each variety, under careful pairing, capable of reproducing its own pecu- 
liarities. This is true also of the dog, the horse, the sheep, the fowl, all 
animals domesticated by man. But, admitting all this, what does it amount 
to ? Has man, with all his skilful application of this law of natural selection, 
been able to change the species of any one of these animals ? His pigeons still 
remain pigeons, his dogs remain dogs, and horses remain horses. He has been 
unable to make any change of structure capable of being construed into a 
new species. Has he been able to make any such change as that, for instance, 
which causes the swimming-bladder of a fish to be converted into the lung 
of a mammal ? But Darwin asserts that man could do all this if we gave 
him a certain greater length of time than the historical period of man’s 
existence would give us. He also seems to imply that man could step over 
this barrier of nature, if the new species of animal were pre-eminently useful 
to man. There is an instance, however, which directly negatives this latter 
assumption. The horse and the ass are two different species of animals, 
according to the usual and natural definition of difference of species ; that is, 
two animals being considered as different species if their hybrids are infertile. 
Now between the horse and the ass there is apparently no greater difference 
of anatomical structure than exists between say the Shetland pony and the 
big dray-horse. According to Mr. Darwin’s own views, the horse and ass 
come from a single ancestor not very remotely removed from either. Now 
it must be admitted on all hands that the mule in many countries is a more 
useful animal to man than either the horse or the ass. Yet man, with all his 
skill, all his watchfulness of the law of variation, and power of adapting it, 
has never produced a fertile mule capable of propagating say a new species of 
animal like the mule. Man, with all his power of interference, has never 
been able to get over this stern barrier of nature— this limitation within 
strictly defined boundaries, not of accidental varieties, but those urged by 
