474 WILLIAM A. HASWELL. 
By Ehlers' the name of “ Driisenmagen,’ or glandular 
stomach, is given to this organ, and, regarding its structure, 
he expresses the opinion that what were formerly looked upon 
as papille are really gland-sacs, which are arranged in a 
radiating manner embedded in the thick wall of the canal, and 
are filled with a dark, finely-granular material. 
Marenzeller? adopts Ehlers’s name for the organ, and de- 
scribes the transverse rows of glands in the various species 
which he found in the Adriatic. 
By Langerhans? the same view of the structure of the organ 
is taken. In his papers on the Annelida of Madeira and of the 
Canaries, that author refers to what I here call the gizzard as 
the stomach, and describes the rows of glands in its walls. 
The only author, so far as I am aware, who has correctly 
described the general structure is Eisig,* who points out that 
the characteristic elements are muscular and not glandular. 
g 
Observations on the Minute Structure of the 
Organ. 
What have been referred to in the descriptions above quoted 
as glands, are, in reality, radiating columns of striated 
muscle, and glands are entirely absent. The reconcilement 
of this statement with those of previous observers—that is to 
say the explanation of the accepted error—is to be found in 
the fact that the radiating columns of striped muscle which 
make up the greater part of the thickness of the organ retain, 
in a certain sense, an embryonic character containing in their 
lungs geschichte wirbelloser Thiere,” the same author refers to those bodies 
as “ papille.” 
1 ‘Die Borstenwiirmer,’ pp. 205 and 206. 
2 «Zur Kenntniss der adriatischen Anneliden,” ‘ Sitzb. der k. Akad. der 
Wissensch.,’ Band lxix (1874) and Band xxii (1875). 
3“ Zur Wurmfauna von Madeira,” ‘ Zeitschr. f. wiss. Zool.,’ Band xxxiv; and 
“Ueber einige Canarische Anneliden,” ‘Nova Acta der ksl. Leop.-Carol.- 
Deutschen Akad. der Naturforscher,’ Band xlii. 
4 « Ueber das Vorkommen eines Schwimmblasenahnlichen Organ bei Anne- 
liden,” ‘ Mittheil. aus. der Zool. Stat. zu Neapel,’ Band ii, p. 261. 
