THE EFFECTS OF HYPERTOXIC SOLUTIONS. 
449 
able from the lai-ger yolk-gx’anules, but usually recognisable 
after the cell-division is completed, lying in the cytoplasm 
near the boundary between the two cells. 
“ In the second segmentation division a similar process takes 
place, but is usually rather less pronounced, the vesicles are 
on the whole smaller, and we doubt whether complete chromo- 
somes ever become vesicular.”^ 
A similar phenomenon within the eggs of Echinoderms has 
recently been described by Konopacki (7). He treated eggs 
of Strongylocentrotus livid us sixty minutes after 
fertilisation with hypertonic solutions (e. g. 50 c.c. sea-water -f- 
9’5 c.c. 2^ M. XaCl solution) for half an houi*, and subsequently 
transferred them to sea-water. His figures show structures 
somewhat similar to those found in the hybrid egfo-s of 
l!lchinus esculentus c? x E.acutus?. It was a study 
of these figures Avhich led to the suggestion that the effect 
of hypertonic solutions upon the fertilised eggs of Echinus 
esculentus aud E. acutus would throw some light on the 
formation of the vesicles found in the above-mentioned ci’oss. 
II. Methods. 
Ripe eggs were fertilised in finger-bowls, and left for one 
hour. They were then transferred to hypertonic sea-water 
for half an hour, aud subsequently put back into normal sea- 
water. The following strengths of hypertonic solutions were 
used. 
(1) Eor Eggs of E. esculentus. 
ries A. 
■50 o.c. sea-water 
+ ^5 c.c. M. XaCl solutionfor i hour. 
. B. 
•50 c.c. ,, 
+ ♦» v.c. „ 
. C. 
■50 c.c. 
+ 7 c.c. ., „ „ „ 
D. 
■50 c.c. 
-t- 8 c.c. .. ,, ,, „ 
E. 
■50 c.c. 
-)- 9’5 c.c. ,, ,, ., ,, 
. F. 
■50 c.c. 
-t- 2o c.c. ., ., ., 15 min. 
. G. 
■50 c.c. 
4- do c.c. ., ,, „ i hour. 
' Quoted from ’ Proc. Camh. Phil. Soc.,’ vol. xvi, pt. V, 1911, p. 41.5. 
