238 NATURE'S CRAFTSMEN 
it seemed as though the egg mass were all inside; 
the part hanging looked like mere streamers or 
decorations of some sort.” 
“ Why didn’t you my so, then? ” Uncle John 
queried, relieved. “ For what you observed be¬ 
tokens that the nursery does not belong to Mrs. 
Back-swimmer at all! It is the property of the 
water scorpion, and of a particular one of the 
scorpions ,—Madam Ranatra. There are two 
species in this interesting family. Madam Ra¬ 
natra is long, thin and slender. Her nursery is 
always embellished with seven streamers. If we 
were to sever one of these, we should find that it 
is in truth a little air-tube. Its function is not 
altogether certain, but doubtless it supplies free 
ventilation to the eggs and later to the tiny 
youngsters, and further affords them a safe pas¬ 
sage into the water. 
" Madam Nepha is the other member of the 
water scorpion tribe. She is flat and oval and as 
unlike her cousin Madam Ranatra as it is possible 
to imagine. They have, however, several fea¬ 
tures in common: their fore legs are swollen and 
fitted for grasping; at the anal end of the body 
each bears two tail-like hollow tubes; when united 
these form a circuit to convey air to the insect 
while the rest of its body is under water. Both 
are pirates of great ability, attacking small fishes 
and other water insects. Madam Nepha’s nurs- 
