140 GERM-CELL CYCLE IN ANIMALS 
into the cytoplasm in all except the “stem-cell” 
during the early cleavage of Ascaris is well known 
(see p. 174, Fig. 51). A similar process was described 
by Kahle (1908) in Miastor metraloas and confirmed 
by me (Hegner, 1912, 1914a) in Miastor americana 
(see p. 57, Fig. 16). This chromatin-diminution 
process results in the formation of a single primordial 
germ cell containing the complete amount of chroma- 
tin and a number of somatic cells with a reduced 
amount of chromatin. The origin of the germ cells 
has been carefully studied in a number of forms which 
in other respects resemble Ascaris and Miastor, but 
in none of them has such a process been discovered. 
Hasper (1911) was unable to establish it for Chirono- 
mus which is very similar to Miastor in early develop- 
ment, nor has sucha phenomenon been found in Sagitta 
(Elpatiewsky, 1909, 1910; Stevens, 1910b; Buchner, 
1910a, 19106) and the copepods (Haecker, 1897; 
Amma, 1911) and Ciapocera (Kiihn, 1911, 1913) 
which undergo total cleavage and are in certain 
other respects similar to Ascaris. 
The nuclear divisions in the eggs of chrysomelid 
beetles have been examined by the writer with con- 
siderable care, but nothing resembling a diminution 
process was found. Furthermore, theré are no 
evidences of chromatin bodies in the cytoplasm or 
yolk as in Ascaris (Fig. 51) and Miastor (Fig. 18, cR), 
where the cast-out chromatin does not disintegrate 
immediately, but can be distinguished for a consider- 
able period during early embryonic development. 
It seems necessary to conclude therefore that in 
