CHROMIDIA AND THE BINUCLEARITY HYPUTHESES. 307 
malaria parasite, In a recurrence of malaria—explained by 
Schaudinn (’02a) as a kind of sexual process — is also 
accounted for by Hertwig (06) as a process which corrects 
the karyoplasmic relations. 
The basis of this hypothesis is now so wide that it will be 
quite beyond the scope of this essay to discuss the large mass 
of literature relating to it. There are already many striking 
experimental facts in favour of the correctness of the hypo- 
thesis, and even if it is not destined to take its place as 
one of the fundamental theories of cytology it will have 
served as a working hypothesis of the very greatest import- 
ance. 
The other hypothesis which sprang from the facts concern- 
ing chromidia is the hypothesis of binuclearity. It 
gradually took shape in the later work of Schaudinn, but has 
found its most ardent advocate in Goldschmidt (04a, 705). 
From his work on nematodes (cf. p. 300), and a consideration 
of chromidia in the Protozoa, Goldschmidt came to the 
following conclusions : 
‘““(1) Every animal cell is by nature! binucleate ; it con- 
tains a somatic and a propagatory nucleus, The former 
presides over somatic functions, metabolism and movement 
The propagatory nucleus contains especially the 
hereditary substances, which also possess the ability to 
generate a new somatic nucleus. 
“ (2) Both kinds of nucleus are usually united into a 
single nucleus—the amphinucleus. Separation may take 
place to a greater or less extent 
“ (3) Complete separation of the two kinds of nucleus can 
be seen in only a few cases, in connection with reproduction 
in Protozoa and also in oogenesis and spermatogenesis of 
Metazoa, 
(4) In tissue cells the separation may be quite unnotice- 
able. . . . An almost complete separation may occur in 
ganglion and muscle cells. The somatic nucleus lies in the 
cytoplasm as the chromidial apparatus, 
1“ Threm Wesen nach.” 
