282 GERM-CELL CYCLE IN ANIMALS 
cell described by the same investigators. “‘The 
mitochondria are almost never at rest, but are con- 
tinually changing their position and also their shape. 
The changes in shape are truly remarkable, not only 
in the great variety of forms, but also in the rapidity 
with which they change from one form to another. A 
single mitochondrium may bend back and forth 
with a somewhat undulatory movement, or thicken 
at one end and thin out at the other with an appear- 
ance almost like that of pulsation, repeating this 
process many times. Again, a single mitochondrium 
sometimes twists and turns rapidly as though 
attached at one end, like the lashing of a flagellum, 
then suddenly moves off to another position in the 
cytoplasm as though some tension had been re- 
leased.” Mitochondria may also be stained intra 
vitam, especially with dahlia violet and Janus green. 
Most of the fixing solutions ordinarily used for cyto- 
logical purposes destroy the mitochondria. The 
methods which seem to give the best results have 
osmic acid or formalin as a basis, such as those de- 
vised by Altmann (see Lee, 1905, p. 43), Benda 
(Lee, 1905, p. 223), Meves (1908), and Regaud 
(1908, p. 661). Benda (1903) claimed that all 
cellular structures which stained violet by his method 
were of a mitochondrial nature; but this has not been 
found to hold true. Undoubtedly the many bodies 
which have been discovered in cells are of several 
sorts, and only by a thorough study of their staining 
qualities, morphological aspects, and biological réles 
can they be identified. Benda’s crystal violet 
