CECONO'My OF INSECT$. 
39 
affi 1 - f reat symmetr y in rings round the smaller twigs of trees', others 
X . tern to the surface of leaves: and again, others lodge them in the 
devices of trees. 
all th° j^ e,Uer "> Phiyganea, Libdhilu, and Gnat, hover over the water 
ther G t0 dro P tlleir eggs : these hatch in the water, and continue 
t re while in the larva and pupa form, quitting the water only when 
( ' a ttain the winged state. The mass formed by the eggs of the gnat 
resembles a little vessel, and floats on the surface. This insect is said to 
1 eposit only one egg at a time ; the first is retained by means of the legs, 
lea dropped, till a second is deposited next to it, then a thi rd, fourth, and 
urther number, till the mass becomes capable, from its symmetry, to 
i ' l 'l'l )ort itselt upright. Many moths cover their eggs with a thick bed 
° , alro ' down, collected from their own body ; others cover them with 
a glutinous substance, whic h when hard protects them from the ill ef- 
tects of moisture, rain, and cold. The solitary bees and wasps pre- 
pare nests in the earth, hollow trees, or cavities in old walls, wherein 
they place a quantity of food for the support of the young brood when 
they break from the egg. The ants are known to construct nests in 
t e earth, in which their eggs are placed with the utmost care. Some 
deposit their eggs in the larva of other insect-, chiefly those of the 
, and butterfly kind; and having passed through all their changes 
their bodies, become what is termed the ichneumon-fly. The 
trasteroplnlus Equi (bot-fly) deposits its eggs on the bodies of horses in the 
following remarkable manner. When the female has been impregnated, 
and the eggs suthciently matured, sl.c seeks among the horses a sub- 
hod/neaT PUr '-°f ; ant j approaching him on the wing, she carries her 
body nearly upnght m the air, and her tail, which is lengthened for 
he purpose curved inwards and upwards: in tins way she approaches 
for a P fe where deposit the egg; and suspending herself 
adher n i T 1 ',! bef ° rU U ’ suddenl y dam u P ,m it, and leaves the egg 
the °' u : hau ' : * h ® hardly appears to settle, but merely touches 
The <> 1 1 f k<dd out 0,1 *hc projected point of the abdomen, 
with o, m :l de ’? ;will<!re h i r means o1 ' a glutinous liquor secreted 
second er, ™ . 611 6aVe ? tlle horse at a small distance and prepares a 
wav Tt r tU ’ r smg lierself before the part, deposits it in the same 
thisUr " l TT dnes > and 'he egg becomes finnly glued to theiiair: 
placed on oi e 1^ ^ bese * lcs tl * our or fire hundred eggs are sometimes 
lhe knee is the P art <m which these flies are most fond 
'he should “IT , e8SS i wA ’ le , Xr 10 this 011 the ^de and back part of 
hut it is a far, d ? SS f t«l uent }j' lhe extreme ends of the mane. 
promiscnouslv 'I, 0r l 1116 fly does not P^ce them 
most likely She .° l ^ ebod \ but cons tantly on those parts which are 
**»» ra ™ 
