• J. GRAY. 
45 U 
(2) For Eggs of E. acutus.^ 
Series A. 
50 
c.c. sea-water -)- 
5 
c.c. 2|M. NaCl solution for K hour 
„ B. 
50 
C.C. 
+ 
(5 
c.c. „ „ ,, 
„ c. 
50 
c.c. ,, 
+ 
1 
c.c. „ „ 
,, D. 
50 
c.c. „ 
+ 
8 
c.c. ,, „ 
„ E. 
50 
c.c. „ 
-b 
10 
c.c. „ ,, ,, 
„ E. 
50 
c.c. 
+ 
15 
c.c. „ „ „ 
The best fixative for these eggs has been found to be a 
mixture of corrosive sublimate and acetic acid (saturated 
solution of corrosive sublimate in sea-water 95 parts, glacial 
acetic 5 parts), and this has been used throughout. Sections 
of the eggs were stained with Heidenhain’s iron-hajmatoxylin, 
other stains only being used for investigating particular 
structures. 
III. Descriptive. 
(1) The Effects of Hypertonic Solutions upon the 
Eggs of E. esculentus. 
Series A. — Eg'os were treated with 50 c.c. sea-water -|- 
5 c.c. 2^ M. NaCl solution for half an hour. 
The division figures for the large majority of these eggs 
are quite normal for the first segmentation. Only a few 
exceptions were found in which abnormalities could be 
detected. Fig. 1 shows a nucleus in which there is a distinct 
' A comparasion of the effects of various strengths of hypertonic 
solutions upon eggs derived from the same female shows an apparent 
inconsistency in the degree of abnormality caused by these solutions in 
respect to their strength ; for example, series C of the eggs of E. a cut us 
appears to be less affected in some way than the series B, although 
treated with a stronger solution. As, however, the exact way in which 
such treatment affects the chromatin is unknown, it is impossible to say 
whether this is due to the specific strength of the solutions used, or to 
more general causes. Again, in some cases the individual properties of 
an egg appear to determine to what extent it is affected by abnormal 
treatment; this is well seen in series C of the eggs of E. esculentus, 
in which different mitotic figures show a very wide range in their degree 
of abnormality. 
