406 TRANSFORMATIONS OF INSECTS. 
There are several well-authenticated instances of bot flies 
attacking men, but it is probable that this is an accidental 
occurrence, and that they are the parasites of the monkey or 
dog. 
There are some very extraordinary flies which inhabit the sea, 
and Packard describes the larva of a species living on floating sea 
grass. He noticed that they were transformed into pupe, and 
that in nineteen days the second metamorphosis into the fly was 
perfected. He also describes an Lphydra whose larva lives in the 
strong salt works of Illinois and under the sea-weed on the shores 
of Narragansett Bay. 
The Ticks are Diptera without wings, or which have them ina 
Melophagus ovis. Leptatena cervi. 
rudimentary condition. They have a sucker, and live parasitically 
upon all sorts of creatures. 
The Sheep Tick, JZelophagus ovis, has a wingless and hairy 
body and a long proboscis. The young are developed within the 
body of the parent until they attain the pupa state, and then the 
pupa in its case, which is nearly as large as the whole insect, is cast 
forth. Packard notices the Bat Tick, which has a small body and 
enormous legs, and it is either blind or provided with four simple 
eyes. These insects are of small size, being only a line or two in 
length. 
The Stag Tick, Leptotena cervi, like the Sheep Tick, has no 
wings, and remains attached to the animal; but some Bird Ticks 
have very small wings, which enable them to leave one animal 
for another. These degraded Dzptera are the connecting links 
between the true insects and the spider and mite families. 
