No: 2:5 ZICRODEVUTOPOS (GRVELOTALPA COSTA. 303 
each day; but, although the seaweed was carefully searched, the 
number of eggs in the segmentation stages found in the material 
brought in on one day was out of all proportion to the number 
of eggs twenty-four hours old found in the material brought in 
the next day from the same place. The animals do not hide 
in the mud during the.early period of development of their 
eggs, because the bottom of the pool in which they were col- 
lected was composed of a black refuse, which gave off so much 
marsh gas that the animals could not live in it. By carefully 
watching those kept in captivity, I observed that when there 
was a moulted amphipod shell floating at the surface of the 
water, an animal which had just deposited its eggs was almost 
always to be found in the dish, and in this way the early stages 
were obtained. 
The females were caught and firmly held with a forceps 
while the eggs were removed from the brood pouch with a dis- 
secting needle. The eggs were then killed in a modification 
of Kleinenberg’s picro-sulphuric solution, in which sea water 
was substituted for the ordinary distilled water. This solution 
gave better results than the ordinary Kleinenberg killing fluid, 
_which distends the egg. Corrosive sublimate, as suggested by 
Della Valle, also distends the egg and injures the protoplasmic 
structure. The living egg contains a fluid substance which 
exudes into the space between the surface of the egg and the 
chorion as soon as the egg is killed. This fluid substance 
coagulates and is stained by haematoxylin, the stain, however, 
being extracted by the acid alcohol before the protoplasm is 
decolorized. I could find no killing fluid which would prevent 
this exudation. Hot corrosive sublimate, Perenyi’s, Flemming’s, 
and Kleinenberg’s fluids, alcoholic picro-sulphuric acid, and hot 
water all affected the egg, in this respect, in the same way. 
With the modified Kleinenberg solution the eggs shrink con- 
siderably, but the parts are not distorted, and good, clear nuclear 
figures were always obtained. The protoplasm showed no ab- 
normal vacuolization, such as occurred when corrosive subli- 
mate was used. 
The chorion closely invests the fresh egg, but in the killed 
specimen there is a large space between it and the surface of 
