1883. ] in the Head of Winged Insects. 1135 
by different authors is very variable, while it is popularly sup- 
posed that the head corresponds to a single segment, and that the 
different pieces are simply “ subsegments.” We will quote from 
Newport, article Zzsecta, in Todd’s Cyclopedia of Anatomy and 
Physiology, the views perhaps generally entertained on this 
subject. 
“ According to the investigations of the most careful observers, 
Savigny, Audouin, Macleay, Kirby, Carus, Strauss-Durckheim, 
Newman and others, every segment of the perfect insect is made up 
of distinct parts, not always separable from each other or developed 
to the same extent, but existing primarily in all. It is also believed 
that the head itself is formed of two or more segments, but the 
exact number which enter into its composition is yet a question, 
So uncertain are the opinions held upon this subject, that while 
Burmeister recognizes only two segments, Carus and Audouin 
believe there are three, Macleay and Newman four, and Strauss- 
Durckheim even so many as seven. These different conclusions 
of the most able investigators appear to have arisen chiefly from 
too exclusive examinations of the head in perfect insects, without 
reference to the corresponding parts in larve. It is only by com- 
paring the distinctly indicated parts of the head in the perfect in- 
sect with similar ones in the larva that we can hope to ascertain 
the exact number of segments of which it is composed. In the 
head of the perfect insect there ought to be found some traces of . 
the flesh fly, is one of the lowest forms we have yet examined, 
and we have already seen that its head appears to be formed of 
four and perhaps even of five segments. This is the greatest num- 
hes have been developed from several segments to form the per- 
€ct cranium and its appendages. It ha 
