No. 394.] REVIEWS OF RECENT LITERATURE. 833 
PHYSIOLOGY. 
Ocular Changes Induced by Low Temperature.— Du Bois- 
Reymond long ago pointed out that when a frog is subjected for a 
considerable period to a freezing temperature the animal responds 
by contracting the pupils and closing the eyes. Dr. G. Abelsdorff 
(Centralblatt fiir Physiologie, Bd. XIII, p. 81) has observed a third 
ocular symptom, namely, a change in the color of the pupil from 
black to a gray or milk-white. This is due to the formation of a 
temporary cataract in the cortical part of the lens. On allowing 
a frog to recover from a semi-frozen condition, the animal regains 
its activity before the lens is clear and is for the time being blind; 
eventually the cataract disappears, and the frog is in all respects 
normal. The author suggests that cataracts of this kind may occur 
naturally in hibernating animals. G. HP. 
Birch’s Physiology. — A new class book of elementary practical 
physiology has been prepared by Professor De Burgh Birch.! The 
first hundred pages are devoted to an account of the construction 
and use of the microscope, ordinary histological methods, and mam- 
malian histology. The account is necessarily meager and decidedly 
less satisfactory than that given in the ordinary histologies of the 
day. Thus in the matter of microtomes for paraffin work, a small 
hand microtome and the old-fashioned Cambridge rocking microtome 
are the only ones mentioned. The second part of the book, some 
sixty pages, deals with the chemistry of the body, including food, 
blood, bile, and urine. The third and concluding part, of about 
ninety pages, is devoted to experimental work on nerve and muscle, 
with a few directions for work on the circulation and some of the 
senses. The illustrations are sufficiently numerous, but poorly 
described, so that one is left to guess at what much of the lettering 
means. It is a question whether such books should not be called 
rudimentary rather than elementary. G H.P. 
Formation of Fibrinogen. — The formation of fibrinogen in the 
blood of mammals has been investigated by Albert Mathews.? The 
fibrinogen in the blood of a cat may be removed by repeated bleed- 
1 Birch, De Burgh. A Class Book of Elementary Practical Physiology. Phila- 
delphia, P. Blakiston’s Son & Co. 1899. 273 pp. 
2 Mathews, A. The Origin of Fibrinogen, The American Journal of Physiology, 
vol. iii, pp. 53-85. September, 1890. 
