1877.] Recent Literature. 109 
tion of special features from a large corps of well-known scientific men. 
The opening paper treats of the geographical distribution of the animal 
life of the West, as shown by Lieutenant Wheeler’s explorations. ‘This 
is followed by the account of the mammals observed, written by Dr. 
Elliott Coues and Dr. Yarrow, which goes extensively into the synon- 
omy of the species mentioned, and gives copious notes upon habits, ete. 
Although the collections were large there were no novelties, and hence 
no plates accompany this paper. Chapter III., Ornithology, is by Mr. 
H. W. Henshaw, and is illustrated by fifteen plates of new species or 
varieties of birds. They are drawn by Robert Ridgway, and well drawn, 
ut the chromo-lithographic process of coloring has failed to give a 
worthy effect in several cases, and some of the plates look cheap. The 
text of the Ornithology is full of news, and great praise belongs to Mr. 
Henshaw for his active and careful observance of the manners and songs 
of the little-known birds of the Southwest. This is the most entertain- 
ing and the longest chapter in the volume. Dr. Yarrow himself writes 
the report upon the Batrachians and Reptiles, of which a large series of 
great value was secured, and unites with Prof. E. D. Cope in describing 
the fishes, which have been somewhat neglected by Western expeditions 
heretofore. Both of these papers are accompanied by many finely en- 
graved plates, partially colored; and both are preceded by-a discussion 
of general characteristics. The collections of Hymenoptera are reported 
upon by E. T. Cresson and Edward Norton; the Diurnal Lepidoptera, 
by Theodore L. Mead and W. H. Edwards ; new species of Zygenide 
and Bombycide, by Richard H. Stretch; the Diptera, by Baron Osten- 
Sacken ; the Coleoptera, by Henry Ulke; the Hemiptera, by Professor 
Uhler; the Orthoptera, by Professor Thomas; and the Neuroptera, by 
Dr. Hagen. Dr. Yarrow, with quite unnecessary apologies as to unfit- 
hess, presents the report upon the Mollusks, showing that even the more 
barren plains of New Mexico and Utah support many species of terres- 
trial and fluviatile mollusks, as well as the mountain meadows of the 
more Northern Territories ; and extending almost or quite across the con- 
tinent, the range of some of our common Eastern species. The final 
chapter is by Professor Verrill upon fresh-water leeches. This last 
half of the book, also, is adorned with a large number of plates finely 
drawn and exquisitely colored. 
Weismann’s Finat Causes or Transmutation.! — Perhaps the 
most remarkable biological work of the year is Prof. August Weismann’s 
treatise on the Final Causes of Transmutation, forming the second part 
of his Studies on the Theory of Descent. The first part of the work, 
entitled Seasonal Dimorphism, appeared in 1875. The present work is 
divided into four divisions, of which the first presents a striking array of 
_| Studien zur Descendenz-Theorie. LI. Ueber die letzten Ursachen der Transmuta- 
tonen. Von Prof. August Weismann. Mit fünf Farbendrucktafeln. Leipzig. 
1876. &vo, pp. 336. 
