THE ANIMAL CELL IN THE LIGHT OF 
RECENT WORK. 
BY GILBERT L. HOUSER. 
Professor of Animal Morphology in the University of Iowa. 
With the discovery of the centrosome, microscopical 
work on the animal cell apparently reached its culmina- 
tion. It was predicted that further study would yield 
little more than the details of larger facts already known. 
The last few 7 years have marked the addition of just such 
details in even greater measure than was imagined; but it 
is also true that altogether unexpected contributions have 
been made from work along other than classic microscop- 
ical lines. Especially to be mentioned are: (1) the appli- 
cation to the cell of the data and the methods of physical 
chemistry; and (2) the extension of experimental biology 
to the field of the animal cell. The solid facts derived from 
these newer studies are already numerous, with every 
indication of vigorous growth occurring daily. But before 
the full value of these new facts can be appreciated, they 
must be coordinated with the older conceptions. Prob- 
ably at no time following the reorganization of the cell- 
theory by Max Schultze in 1861 has there been more 
urgent need for a critical survey of results than the pres- 
ent moment. The writer does not claim completeness for 
the paper here presented; the space prescribed is all too 
limited for even a complete summary. Rather, the attempt 
has been made briefly to outline certain facts which have 
an important bearing on some of the modern problems of 
the animal cell. 
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