286 
Psyche 
[December 
Results 
Tergal glands 
a. Pygidial gland 
In a detailed anatomical study of Myrmica rubra Janet (1898) 
described a pair of clusters of a few glandular cells, located under 
the third gastric tergum. Each cell sends a duct through the 
intersegmental membrane between the third and fourth gastral 
terga. We discovered a similar, but considerably larger paired 
glandular complex at the same anatomical position in Novomessor 
cockerelli and N. albisetosus (Holldobler et al 1976). Kugler (1978) 
recently investigated a number of myrmicine ants and in many of 
them he found the gland, which had “distinct reservoirs, produced 
by invagination of the intersegmental membrane between abdomi- 
nal tergum 6 and tergum 7 (pygidium)”. Kugler suggested that these 
glandular organs be called pygidial glands. We accept this terminol- 
ogy, because it describes the anatomical designation of the organ 
more precisely than the term “dorsal gland” or “tergal gland”, 
originally suggested (Holldobler et al 1976, Holldobler and Haskins 
1977). However, it has to be pointed out that the pygidium of the 
ants (the last exposed tergum) is the 7 th abdominal tergum and is not 
homologous to the pygidium of the Coleoptera (8 th abdominal 
tergum). Hence, the pygidial glands of ants are not homologous to 
the pygidial glands of Coleoptera. 
In a previous study (Holldobler and Haskins 1977) we found 
pygidial glands with large reservoirs in several ponerine and myr- 
meciine ants ( Amblyopone , Paraponera, Ectatomma, Odontoma- 
chus, Pachycondyla, Platythvrea, Rhytidoponera, Myrmecia ) and 
we demonstrated that the virgin females of Rhytidoponera metallica 
attract males by the release of a pheromone from these glands. In his 
anatomical studies of Rhytidoponera metallica and R. convexa, 
Whelden (1957, 1960) described a pair of cell clusters each com- 
prising 8-15 glandular cells. Each cell sends a duct through the 
membrane connecting the 6 th and 7 th abdominal segments. We are 
now certain that Whelden already had discovered the pygidial gland 
in Rhytidoponera; his histological methods, however, may not have 
enabled him to detect the large reservoirs associated with the 
glandular cell clusters. Similar paired glandular structures were 
found by Whelden (1957) in the ponerine species Stigmatomma 
(= Amblyopone) pallipes. 
