360 REVIEWS 
of the growth force of the individual or the force of gravitation. 
As the normal laws of growth of the individual are thwarted and 
diverted by external conditions,so undoubtedly a greater or less modifi- 
cation of the course of evolution has been produced by the conditions 
of environment. 
‘‘When we attempt to explain the course of evolution by tracing it 
backward from the differentiated, adjusted organisms to its ancestors, 
it is natural to place great importance upon the fact of the accom- 
plished adjustment of the individual to its particular environment ; 
but when the point of views is reversed and the organism is traced 
from the earlier geological periods through the ages down to the present 
time, the conviction becomes impressed upon the student that environ- 
mental conditions are but the medium through which the organic 
evolution has been determinately ploughing its way.” Saas 
Canadian Fossil Insects. By S. H. ScuppER. Contributions to 
Canadian Paleontology, Vol. II., Part. 1 (1895). 
This publication includes three different papers by Prof. Scudder. 
1. The Tertiary Hemiptera of British Columbia. Descriptions are 
given of nineteen species from three different localities—Quesnel on 
the Fraser, the north fork of the Similkameen River and Nine Mile 
Creek flowing into Whipsaw Creek, a tributary of the Similkameen. 
Dr. Dawson considers the two latter localities to be portions of a single 
ancient lake, so only two basins are concerned. ‘The two basins afford 
specimens of very different character and may prove to represent dif- 
ferent stages inthe Tertiary. The age of the beds is probably as old 
as the Oligocene. 
The great diversity of this ancient insect fauna may be judged from 
the fact that in nearly every case each specimen must be referred to a 
distinct species, and in only one case can two species be referred to the 
same genus. The most striking feature of the fauna is the large size of 
theindividuals which compose it. 
2. The Coleoptera hitherto found fossil in Canada. Fossil Coleoptera 
have been found in seven distinct localities at three very different hori- 
zons, viz., Post-Pliocene, thirty-two species, lower Tertiary, fourteen 
species, and Cretaceous, one species. . 
The most interesting fauna is that from the inter-glacial deposits of 
