51 
Saturday, Mr. Hennau spoke of the value of the ‘‘ towing net,” 
which could be used from the Pier as well as from a boat in ob- 
taining surface life, such as the egys of fish, medusve, the zoce of 
crabs, &c, 
July 28th.—Microscopical Section. ‘¢On the Eggs of Articulata,” by 
Mr. T. W. Wonror. 
While the eggs of all animals differed in their appear- 
ance and markings, the general characters were the same, 
viz., the germ vescicle, the yolk substance, and the ves- 
cicular envelope; the chemical constituents of these being 
albumen, fatty matter, and a substance not precipitated in 
water ; the whole was enclosed in a shell membrane, or chorion, 
in some cases provided with a lid, or operculum, to facilitate 
the escape of the larva. 
This lid was very palpable in some eggs, but neither so 
evident nor its use so apparent in others, seeing the larva ate 
their way through the shell itself. 
At the apex of the eggs was a point called the micropyle, from 
which it was asserted the larva always emerged, and with which its 
mouth was connected ; but the examination of a large number of 
eggs of different species had convinced him that so far from the 
mouth of the larva being situated at the micropyle, or that the 
creature escaped by it, being the fact, it was quite the exception in 
a vast majority of cases. 
The colour of eggs seemed to depend on the colour of the 
yolk-globules, and changed as the embryo advanced, eventually 
becoming a very dark brown or black. In some eggs the changes 
could be watched ; but in others the chorion, consisting of three 
layers, was so thick as to prevent examination, except by very 
delicate dissection. 
The females, as a rule, deposited the eggs; but many 
examples occurred in which they were retained by her and 
deposited as larve. ‘This was seen in the crustacee, many 
of which hatched them, either in external ovaries or in a 
space between the body of the parent and the posterior 
