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DEGENERATION AND DEATH IN ENTAM@BA RANARUM. 717 
part, on the other hand, though it remained capable of 
movement for many days, invariably died inthe end. Whilst it 
continued to live, however, it was seen to be incapable of 
ingesting food material, and apparently had but little power 
to digest further such food as was already present. Hofer 
concluded that the power of locomotion exists in the cytoplasm, 
independent of the nucleus: but that ingestion and digestion 
of food by the cytoplasm are possible only with the co-opera- 
tion of the nucleus. 
These two important conclusions are supported by the facts 
which I have just described in Entamceba ranarum. 
Enucleation in this case, however, is gradual, so that the change 
of properties in the resulting organism is not so sharply marked 
as in the case of a vivisected amoeba. But the resulting 
animal, without a nucleus, is—as we have seen—capable of 
locomotion, but incapable of ingesting and assimilating food. 
The phenomena of physiological degeneration and death 
which I have described in E. ranarum in the preceding 
section, are paralleled in other Protozoa (cf. Hertwig [4, 6, 
8}, etc., Dobell [1,3]). The most striking parallel is seen in 
the case of Amceba proteus, which has been shown by 
Prandtl (11) to undergo a process of physiological degenera- 
tion very similar to that which I have observed in HK, ranarum. 
I wish here to say a few words regarding the cause and 
significance of these phenomena. As the majority of the facts 
have been admirably dealt with already by R. Hertwig, I will 
limit myself to as few remarks as possible, 
Richard Hertwig, who originated the term “ physiological 
degeneration” for these phenomena, seeks to elucidate them 
by means of his hypothesis of the karyoplasmic relation 
(“ Kernplasmarelationstheorie”). The degeneration is the 
result of the overgrowth of the nucleus as compared with the 
cytoplasm. If this overgrowth is not corrected—e. @. by the 
elimination of nuclear matter—then death results. Hertwie’s 
own observations upon Actinospherium, Dileptus, 
Paramecium, etc., speak strongly in favour of this 
interpretation. 
