Reviews and Book Notices. 39 
These nests were nearly together, one of the double cells 
being fixed in one angle and the other in the opposite angle. 
I dissected one pair of cells, and found in the upper one six 
green caterpillars rolled up very much like those illustrated on 
page gi in Peckhams’ book on Wasps.* Some of these cater- 
pillars were still alive. In the lower cell I found two larger 
caterpillars. The nests were about three quarters of an inch 
long and joined together one above the other. _ I left the other 
double cells intact for further observation. 
On the 22nd of August, on going to my office, I found the 
black wasp very busy at work on the top of the untouched 
double cell, so much so, that I got close to it and watched it for 
some time. Then the wasp dropped to the ground close to 
where I was standing and busied itself among some soft mud. 
Having evidently gathered up some of the mud, the wasp flew 
back to the cell, and set to work to strengthen the previously 
closed orifice. When it had accomplished its task, the little 
black worker flew overhead and I saw it no more. The top of 
the cell where it had been working was wet. I kept a watch on 
these mud cells, expecting some development in the spring, but 
one day in December I found that the cells were broken away, 
nothing being left but the ragged edges where the mud had 
stuck to the stone, resembling, but on a smaller scale, the 
remains of a broken swallow’s nest. The cells were probably 
accidently destroyed by children. I saw no Solitary Wasps 
during the year 1906. 
—_9@__ 
Darwinism and the Problems of Life. A study of familiar animal 
life. By Conrad Guenther, translated by Joseph McCabe. London, 
1906, Owen & Co. 436 pages, 12/6. 
Both the translator and publisher of this work earn our gratitude for the 
facilities they have now given for enabling English readers to possess, in 
a convenient form, Prof. Guenther’s most interesting volume. In it the 
author’s aim is to vindicate the value and importance of Darwin’s work, and 
the book is largely devoted to proving the truth of Darwin's doctrine. 
‘ Every care has been taken to distinguish between facts and probabilities, 
and it has been clearly pointed out what general deductions may or may not 
be drawn from Darwinism. The ease with which the theory of evolution 
is grasped too readily, disposes people to regard Darwinism as the one true, 
natural, and sound view of the world-process. . . . The manner of presenta- 
tion is simple, because the work is written for the general reader. No 
knowledge of science is pre-supposed, and the reader is briefly informed on 
all the questions that have a bearing on the theory of evolution.’ From a 
perusal of the volume, it is obvious that the author has carefully consulted 
the now very extensive literature dealing with the subject discussed. The 
book, though massive, is very light, and the large size and clearness of the 
type makes its perusal particularly pleasant. 
* «Wasps, Social and Solitary,” by Mr. and Mrs. G. W. Peckham, 1905. 
1907 February 1. 
