20 
easily secured by capturing the ovipositing female and touch- 
ing her abdomen repeatedly to some water in a small dish, 
holding her only by the fore wings back to back, while those 
which oviposit in plants or soft wood may be watched and the 
stems or wood examined afterward. Experiments indicate that 
imagos will not voluntarily oviposit while in captivity. 
Formalin is not a good preservative for any of the larger 
insects. The best preservative is strong alcohol carefully 
heated in a water-bath. The hot alcohol penetrates more rap- 
idly than cold, arresting internal decomposition, and thus re- 
tains the beautiful but fugitive colors of the imago. The usual 
process of sterilizing and fixing the tissues by heating in water 
in a test-tube to the boiling point before transferring to alcohol 
is eminently satisfactory for aquatic forms as a rule, but in the 
Anisoptera this expands the air in the rectal gill-chamber and 
distorts the abdomen somewhat, while in the Agrionide, as in 
the E’:phemeride, the flat external gill-plates are badly injured 
by inflation and gumming together. The slender and brittle 
abdomen of the imago breaks off very easily, and a bristle or 
fine non-corrosive wire should therefore be passed lengthwise 
through the body as far as the tip of the abdomen, but not so far 
as to project among the terminal appendages. A couple of insect 
pins, inserted lengthwise, one at each end of the body, are 
used by some. Specimens for the cabinet may be spread like 
Lepidoptera. For shipment or exchange they are usually in- 
closed in soft papers folded diagonally. 
Rearing the nymphs is not usually difficult. They need 
plenty of clean water, something to crawl out on, and room to 
transform in. A pail or tub covered with mosquito-netting 
answers nicely. It must get plenty of sunshine, but not so much 
as to overheat the water. Ifthe breeding-cage can be immersed 
in the water of the stream or lake where the nymphs live, suc- 
cess is almost assured. They may be fed bits of fresh meat or 
fish, insect larve, flies, or the smaller aquatic Hemiptera. If 
meat is fed, it must be kept in motion before them, as they will 
refuse anything that does not seem to be alive. Mr. Needham 
