4 THE CANADIAN NATURALIST. [Vol. vil. 



having the greatest luimber of joints, and Barrande shows that 

 these last cannot be held to be less perfect than those with the 

 medium numbers. Further, as Barrande well shows, on the 

 principle of survival of the fittest, the species with the medium 

 number of ioiuts are best fitted for the stru2:£:le of existence. 

 But in that case the jn'imordial Trilobites made a great mistake 

 in passing at once from the few to the many segmented stage or 

 vice-versa, and omitting the really profitable condition which lay 

 between. In subsequent times they were thus obliged to un- 

 dergo a retrogade evolution, in order to repair the error caused 

 by the want of foresight or precipitation of their earlier days. 

 But like other cases of Lite repentance, theirs seems not to have 

 quite repaired the evils incurred; for itw^as after they had fully 

 attained the golden mean that they failed in the struggle, and 

 finally became extinct. '•' Thus the infallibility which these 

 theories attribute to all the acts of matter organizing itself, is 

 gravely compromised," and this attribute would appear not to 

 reside in the trilobed tail, any more than according to some in 

 the triple crown. 



In the same manner, the pala3ontologist of Bohemia passes in 

 review all the parts of the Trilobites, the succession of their spe- 

 cies and genera in time, the parallel between them and the 

 Cephalopods, and the relations of all this to the primordial 

 fauna generally. Everywhere he meets with the same result ; 

 namely, that the appearance of new forms is sudden and unac- 

 countable, and that there is no indication of a regular progres- 

 sion by derivation. He closes with the following somewhat satir- 

 ical comparison, of which I give a free translation : " In the 

 case of the planet Neptune, it appears that the theory of astro- 

 nomy was wonderfully borne out by the actual facts as observed. 

 This theory, therefore, is in harmony with the reality. On 

 the contrary, we have seen that observation flatly contradicts all 

 the indications of the theories of derivation with reference to the 

 composition and first phases of the primordial fauna. In truth, 

 the special study of each of the zoological elements of that 

 fauna has shown that the anticipations of the theory are in com- 

 plete discordance with the observed facts. These discordances 

 are so complete and so marked that it almost seems as if they 

 had been contrived on purpose to contradict all that these theo- 

 ries teach of the first appearance and primitive evolution of the 

 forms of animal life." 



