GERM CELLS IN THE ARTHROPODA 169 
ments with oxygen and carbonic acid gas indicate 
that a greater amount of Ectosomen occur when the 
egg is developed in the latter, as shown by Fig. 49, I, 
which is from an egg of Cyclops viridis placed one 
hour after deposition into carbonic acid gas for one 
hour. 
When various stains were used it was found that 
the Ectosomen became colored much like the 
cytoplasm. For example, when stained in methylene 
blue followed by eosin the chromosomes were blue 
and the Ectosomen and cytoplasm red, and when 
stained by the methyl green-fuchsin-orange G method 
of Heidenhain the chromosomes were green and 
the cytoplasm and Ectosomen red. 
Amma also attempts to explain the fact that the 
Ectosomen appear at only one end of the first cleav- 
age spindle and in only one of the cleavage cells 
until the two primordial germ cells are formed. 
He rejects the hypothesis Haecker advanced that the 
centrosomes possess an unequal influence upon the 
Ectosomen and that one centrosome attracts all of 
them because it is stronger than the other, and is 
inclined to favor the idea that the Ectosomen are the 
visible evidence of an organ-forming substance which 
is thus distinguished from the rest of the cytoplasm 
as ‘‘Kornchenplasma.” ! 
Fuchs (1913) has confirmed for Cyclops viridis 
1 Amma’s statement is, “dass im Zellplasma des noch ungefurchten 
Copepodeneies ein vom iibrigen Eiplasma qualitativ verschiedenes Koérn- 
chenplasma existiert, welches die organbildende Substanz, die Anlagesub- 
stanz fiir die Geschlechtsorgane darstellt”’ (p. 564). 
