598 KANSAS CITY REVIEW OF SCIENCE. 
correlation be accepted as probable, it must modify many views now held as to 
the antiquity of man. In that case, the modern gravels spread over plateaus and 
in river valleys, far above the reach of the present floods, may be accounted for, 
not by the ordinary action of the existing streams, but by the abnormal action of 
currents of water diluvial in their character. Further, since the historical deluge 
cannot have been of very long duration, the physical changes separating the de- 
posits containing the remains of paleocosmic men from those of later date would 
in like manner be accounted for, not by slow processes of subsidence, elevation, 
and erosion, but by causes of more abrupt and cataclysmic character. This sub- 
ject the writer has referred to in previous publications,* and he is glad to see that 
prominence has recently been given to it by so good a geologist as the Duke of 
Argyll, in a late number of the Contemporary Review. 
It is a great leap backward to pass from the bronze age of Europe to the 
Paleozoic brachiopods of Bohemia; but both may furnish illustrations of the same 
natural laws, as both belong to the same long-continued creative work. Barrande, 
like some other eminent paleontologists, has the misfortune to be an unbeliever in 
the modern gospel of evolution, but he has certainly labored to overcome his 
doubts with greater assiduity than even many of the apostles of the new doc- 
trine; and if he is not convinced, the stubbornness of the facts he has had to deal 
with must bear the blame. In connection with his great and classical work on 
the Silurian fossils of Bohemia, it has been necessary for him to study the similar 
remains of every other country, and he has used this immense mass of material 
in preparing statistics of the population of the Paleozoic world more perfect than 
any other naturalist has been able to produce. In previous publications he has 
applied these statistical results to the elucidation of the history of the oldest group 
of crustaceans, the trilobites, and the highest group of the mollusks, the cephalo- 
pods In his latest memoir of this kind he takes up the brachiopods, or 
lamp-shells, a group of bivalve shellfishes, very ancient and very abundantly repre- 
sented in all the older formations of every part of the world, and which thus 
affords the most ample material for tracing its evolution, with the least possible 
difficulty in the nature of ‘‘imperfection of the record.” 
Barrande, in the publication before us, discusses the brachiopods with refer- 
ence, first, to the variations observed within the limits of the species, eliminating 
in this way mere synonyms and varieties mistaken for species. He also arrives 
at various important conclusions with reference to the origin of species and varietal | 
forms, which apply to the cephalopods and trilobites as well as to the brachiopods, 
and some of which, as the writer has elsewhere shown, apply very generally to 
fossil animals and plants. One of these is that different contemporaneous species, 
living under the same conditions, exhibit very different degrees of vitality and 
variability. Another is the sudden appearance at certain horizons of a great 
nuinber of species, each manifesting its complete specific characters. With very 
rare exceptions, also, varietal forms are contemporaneous with the normal form 
of their specific type, and occur in the same localities. Only in a very few cases 
* «Origin of the World,” Fossil Men.” 
