THE EFFECTS OF HYPERTONIC SOLUTIONS. 
469 
im Plasma, das dadurcli seine Farbbarkeit erhalten hat, wieder 
gelost. tiber die Herkunft der Intensiv gefarbten, grossen 
Klumpen konneii wii- nur Vermutungen aiissern ; einmal 
werden sie wolil Reste von Nukleolarsubstanz entbalten, 
aiidererseits ware aucli daran zii denken, das zu ihrer Bildung 
das viiterlicbe Radiumchromatin beigetraten liat.^’ 
Later stages of such eggs also resemble those of E. acutus 
which have been treated with hypertonic solutions, being 
characterised by very irregular segmentation aud the pi’O- 
duction at times of stereoblastulfe (cf. Hertwig’s text-figs. 
6 , 7 , 8 ). 
Hertwig finds that the introduction of an abnormal sperm 
nucleus into the female pronucleus leads to abnormalities in 
the female chromatin. He concludes, however, that “ diese 
Schadigung des mutterlichen Chromatins allein durch den 
radiumkranken Spcrmakern hervorgerufen sind,” because 
the control eggs behaved normally. He does not entertain 
the idea that it is possible for the female cytoplasm to affect 
the female chromatin either after the break-up of the nuclear 
membrane or before. As a result of the work described in 
the present paper, however, this is a consideration which 
must be entertained, for, as the eggs in this case were not 
subjected to abnormal treatment until an hour after fertilisa- 
tion, any irregularities in the nuclei must be attributed to 
the effects of the deranged cytoplasm of the egg. 
YI. Hybridisation and Pathology. 
The primary effect of the treatment of the fertilised eggs 
of E. acutus with hypertonic solution of medium strength is 
to cause the elimination of a certain number of chromosomes 
from the nucleus. G. Hertwig’s results show that this can be 
likeAvise effected by fertilising normal eggs with sperm which 
has been rendered abnormal. It may be concluded, therefore, 
that elimination of chromatin from the nucleus can be referred 
to patliological conditions of the nucleus itself, and is not 
exclusively a result of hybridisation. 
