(7) 
PROPAGATION AND DEVELOPMENT. 
The adequate treatment of propagation and develop- 
ment in each of the various genera 1s beyond the scope 
of a systematic work such as the present, even if it 
were possible in the present state of our knowledge 
of the subject, but in only a very few species has 
the embryology been worked out, and perhaps not 
exhaustively even in some of these. Inthe Amcebina 
especially are details of life-history lacking, and it is to 
be hoped that competent observers willing and able to 
devote the necessary time will be found to carry out 
further investigations. 
English readers will find most of the information 
which is available on the biology of the Sarcodina in 
the works of Calkins, Ray Lankester, and Minchin, 
especially in the latter’s ‘ Introduction to the study of 
the Protozoa,’ 1912; also in the Cambridge Natural 
History. 
