REVIEWS. 205 




















forceps as they emerge from the nest, or caught with the net 
and then pinned. Refractory colonies may be easily quelled 
by pouring in ether or chloroform, or burning sulphur at 
the aperture, as is the best method of procedure with wasp’s 
nests. 
The solitary species, besides boring in the earth like An- 
drena and Halictus, whose habits have been described in the 
first volume of the NATURALIST, also bore in the stems of 
different plants, such as the elder, syringa, raspberry, and 
blackberry. Nearly fifty species of insects, mostly hymen- 
optera, are known in France to burrow in the stems of the 
blackberry alone! Now is the time to look for their burrows 
in the dead branches. Their presence is usually detected 
by an old hole at the end of a broken branch. The writer 
would be greatly obliged for material to aid him in the study 
of our bees and wasps, and would take pleasure in corre- 
sponding with those interested in the study of their habits, 
and would be very grateful for specimens of the young in 
alcohol, their parasites and nests. 

REVIEWS. 
pe 
Votcantc Rocks.*—The author of this interesting memoir classifies 
Volcanic rocks in five orders. The first order consists of Rhyolite with 
three families, Nevadite or granitic- sees Liparite or porphyritic-rhy- 
Rhyolite proper or Lithodic and Hyaline-rhyolite. The „o 
i mag confines himself in this classification to volcanic rocks of 
tions” d Post-tertiary age, which he subdivides into ‘ massive erup- 
sdk “volcanic eruptions.” The origin of massive eruptions is 
* Princip] iples 
Phil, 
Memoirs presentcr Natural System of Volcanic Rocks. By F. Baron Richtofen, Dr. 
nted to the C of Science, a Å ns May 6, 1867. pp.4 

