418 
PROF. B. T. LOWNE ON THE STRUCTURE AND 
On the Structure and Development of the Ovaries and their 
Appendages in the Blowfly ( Calliphora erythrocephala). By 
B. Thompson Lowne, P.R.C.S., P.L.S., Hunterian Professor 
of Comparative Anatomy in the Royal College of Surgeons. 
[Read 6th December, 1888.] 
(Plate XXVIII.) 
1. Introductory. 
2. Development of the Ovaries and Ova. 
3. The Oviducts and their appendages. 
4. The structure of the Gum -glands. 
5. Theoretical Considerations and Conclusions. 
6. Bibliography. 
1. Introductory. 
The ovary of an insect is known to consist of a number of 
ovarian tubes connected with a single outlet, the oviduct. 
The ova lie within a thin membranous tube, the tunica pro- 
pria , and form an egg-string ; this is enclosed wdthin a follicle, 
the egg-follicle, the so-called peritoneal coat. In each egg-string 
three parts are usually recognized — the terminal thread, the ter- 
minal chamber, and the egg-chamber or chambers. 
In the Blowfly each ovary consists of about a hundred ovarian 
follicles, springing from the dilated anterior end, or calyx, of the 
ovarian duct. When the ovary is mature (PI. XXVIII. fig. 8) 
the terminal threads exist as mere rudiments ( t.f. !), and, properly 
speaking, there are no terminal chambers. In the young ovary, 
however (fig. 6), the terminal chambers are well marked ( t.c .). 
Much discussion is found in the writings of various authors as 
to the nature and import of the terminal thread. 
Brandt (6 # ) maintains that there is no fundamental difference 
between ovaries with and ovaries without terminal threads ( l . c. 
p.21) — “ these are mere prolongations of the ovarian tubes or of 
their peritoneal investment. In the former case they have the 
same morphological significance as the rest of the ovarian tube, 
in the latter they are mere connective or suspensory bands.” 
My own observations have led me to exactly the same conclusion. 
The Terminal Chamber (fig. 6, t.c.) is filled with small cells. 
Stein (24) was apparently the first to distinguish the terminal 
chamber as an important constituent of the ovary ; he calls it the 
* The numbers in parentheses following authors’ names refer to corresponding 
numbers in the Bibliography given at the end of this paper. 
