17 
wards. The valves of bivalve shells should be brought together by 
a string. 
Spiders, scorpions, centipedes or thousand-legs, earth-worms, hair- 
worms, and generally all worm-like animals to be met in fresh waters, 
either clear and running or still and putrid, cannot be better preserved 
than in the strongest alcoholic liquor, and in small bottles or vials. 
I IV. EMBRYOS. 
Much of the future progress of zoology will depend upon the ex- 
tent and variety of the collections which may be made of the embryos 
and foetuses of animals. No opportunity should be omitted to procure 
these and preserve them in spirits. All stages of development will 
be equally interesting, and complete series for the same species are of 
the highest interest. Not only the domestic mammalia, as horse, 
cow, sheep, hog, dog, &c, should be collected, but also any of the 
wild animals, as deer, bears, wolves, foxes, antelope, and any and 
every species. Whenever any females of such mammalia are killed, 
the uterus should be examined for embryos, and the smaller or more 
minute, in many cases, the more interesting. When eggs of birds, 
reptiles, or fish are emptied of their young, these should be preserved. 
It will be sufficiently evident that great care is required to label the 
specimens, as in most cases it will be impossible to determine the 
species from the zoological characters. 
I V. NESTS AND EGGS. 
Nothing forms a more attractive feature in a museum, or is more 
acceptable to amateurs, than the nests and eggs of birds. These 
should be collected whenever they present themselves, and in any 
amount procurable for each species, as they are always in demand for 
purposes of exchange. Hundreds of eggs of an// species with their 
nests (or without, when not to be had) will be gladly received. 
Nests require little preparation beyond packing so as to be secure 
from crumbling or injury. The eggs of each nest, when emptied, may 
be replaced in it and the remaining space filled with cotton. 
Eggs, when fresh, and before the chick has formed, may be emptied 
by making a minute hole at each end, and blowing or sucking out the 
contents. Should hatching have already commenced, an aperture 
may be made in one side by carefully pricking with a fine needle 
