1978] 
Holldobler & Engel — Glands in Ants 
287 
Finally, independently of our investigations, Maschwitz (pers. 
communication) found a pygidial gland in Leptogenys chinensis, 
which he called the “dorsal gland” (Maschwitz and Schonegge, 
1977). 
The new anatomical investigations presented in this paper reveal 
that the pygidial glands are much more common in ants than 
previously assumed. Usually the organ consists of a pair of lateral 
clusters of glandular cells, each cell sending a duct through the 
intersegmental membrane between the 6 th and 7 th abdominal terga. 
Depending on the species, the intersegmental membrane can be 
invaginated to different degrees, so that it can form a more or less 
voluminous reservoir (Fig. 1, 2, 3, 4). If no reservoir is present, the 
glandular structures can easily be missed during the dissection and 
histological sectionings are therefore required to determine whether 
or not the pygidial gland is present. As we have already indicated for 
Novomessor and as confirmed by Kugler (1978) for several other 
myrmicine species, the pygidial gland can be associated with a 
special cuticular structure on the pygidium (7 th tergum), (Fig. 5, 6, 
7). Our histological studies demonstrated, however, that the absence 
of such structures does not necessarily indicate the absence of 
Figure 1. Schematic illustration of glandular cells that send ducts through the 
intersegmental membrane. When the membrane is increasingly more invaginated, it 
forms an increasingly larger reservoir (a to c). 
