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number of entirely new elements—the rise of useful structures frotn 
their minute embryonic, apparently useless, condition, the most vul 
nerable point in the pure selection theory. . . . Upon the 
probability that the mammalian teeth were developed from the 
reptilian type, Cope predicted, in 1871, that the first accessory cusps 
would be found on the anterior and posterior slopes of a single cone 
—i.e., at the points of interference of an isognathous (equal-jawed) 
series in closing the jaws. Much later I showed that precisely this con 
dition is filled ( ? fulfilled) in the unique molars of the Upper Triassic 
Dromotherium. These, with the main cusp, form the three elements 
of the tritubercular crown. Passing by several well-known stages, we 
reach one in which the heel of the lower molars intersects, and, by 
wearing, produces depressions in the transverse ridges of the upper 
molars. At these points are developed the intermediate tubercles, 
which play so important a rôle in the history of the ungulate molars. 
So, without a doubt, every one of the five main component cusps 
superadded to the original cones, is first prophesied by a point of 
extreme wear, replaced by a minute tubercle, and grows into a cusp. 
The most worn teeth—i.e., the first true molars, are those in which 
these processes take place most rapidly. We compare hundreds 
of specimens of related species : everywhere we find the same varia 
tions at the same stages, differing only in size, never in position. We 
extend the comparison to a widely separate phylum and find the same 
pattern in a similar process of evolution. . . . Whatever may 
be true of spontaneous variations in other parts of the organism, 
these new cusps arise in the perfectly definite lines of growth. Now, 
upon the hypothesis that the modifications induced in the organism 
by use and disuse have no directive influence upon variations, all these 
instances of sequence must be considered coincidences. If there is 
no other causal relationship, what other meaning can this sequence 
have ?... Granting the possibility that the struggle for existence 
is so intense that a minute new cusp will be selected if it happens to 
arise at the right point, where are the non-selected new elements, the 
experimental failures of nature ? We do not find them. Palaeon 
tology has indeed nothing to say upon individual selection, but 
chapters upon unsuccessful species and genera. Here is a practical 
confirmation of many of the most forcible theoretical objections 
which have been urged against the selection theory.”—(Nature, 
vol. xli.y pp. 227-228.) 
Here, then, in connection with the palaeontological evi 
dence for the evolution of the horse, we have evidence to 
show, in the opinion of an expert, that it could not have 
been brought about by Natural Selection.