Dorsal and ventral glands have been found in both sexes of _Blatta orientalis_ and _Periplaneta americana_ (Minchin, 1888, 1890; Kul'vets, 1898; Oettinger, 1906; Harrison, 1906; Liang, 1956). The ventral glands are found in the same general region as those of _Eurycotis_. We have also found similar ventrally located glands in both _Periplaneta australasiae_, and _P. brunnea_. The reservoirs which store the secretion of the ventral glands are smaller in _Blatta_ and _Periplaneta_ spp. than those found in _Eurycotis_, _Neostylopyga_, or _Platyzosteria_. In _Blatta orientalis_ the dorsal glands can be everted by pressure on the abdomen; the secretion in these glands, according to Haase (1889), has the typical oriental cockroach odor. Although the dorsal glands of the oriental cockroach are usually given a defensive role (Haase, 1889, 1889a; Kul'vets, 1898; Oettinger, 1906; Konček, 1924), the functions of secretions of these nonepigamic dorsal glands and the ventral glands are still open to question. It is possible that some of the odors produced by cockroaches have functions other than defense or sex attraction. For example, Ledoux (1945) showed that the species odor is largely responsible for the gregarious behavior shown by _Blatta orientalis_ and _Blattella germanica_. The olfactory stimulus acts over a short distance only, and the source of this odor in the insect is unknown. By washing _Blattella germanica_ in warm chloroform Dusham (1918) extracted a wax which had the odor of the German cockroach. However, there is no evidence to show that cockroaches respond to the same cockroach odors that are detected by man. Certain cockroaches have recently been found to have odorous secretions which are produced in tracheal glands. In _Diploptera punctata_ the tracheae leading to the second abdominal spiracles of nymphs and adults are modified into odoriferous glands which produce a mixture of 2-ethyl-1,4-benzoquinone; 2-methyl-1,4-benzoquinone; and _para_ benzoquinone; this material is ejected as a means of defense. The offensive odor emitted by adults and nymphs of _Leucophaea maderae_ also issues from the second abdominal spiracles (Roth and Stay, 1958). _Diploptera_ is capable of ejecting its quinones from either its right or left tracheal gland according to which side of the insect is attacked (pl. 36, A-B). Eisner (1958) found that the secretion repelled the ant _Pogonomyrmex badius_ (Latreille) (pl. 36, C) and the beetle _Galerita janus_ Fabricius when they attacked the cockroach. The spider _Lycosa helluo_ Walckenaer was repelled by large nymphs and adults of _D. punctata_ but young nymphs were usually eaten promptly (Eisner, 1958).