168 Miscellaneous. 



the presence of the two glandular systems, as in the Hemiptera 

 furnished with organs of flight, demonstrates that originally the 

 Cimices possessed normally- constituted elytra and wings. 



Some naturalists, indeed, have thought that these creatures, when 

 adult, represented the pupa-state of other Hemiptera, and that the 

 numher of moults justified their opinion. Now the disappearance of 

 the larval and pupal odoriferous glands coincides with the appear- 

 ance of new odoriferous glands, the exclusive appanage of the adult 

 Hemiptera : then the Cimices capable of reproduction and regarded 

 as pupa3 are not able after another moult to acquire wings ; they 

 are creatures which have attained the last term of their develop- 

 ment. If, like Pjjrrliocoris apterus * of the family Lygajidcs, they 

 are capable of becoming winged, this would be at the time of the 

 last moult, and the appearance of the elytra and wings of normal 

 constitution would coincide with the disappearance of the abdominal 

 glands and the apijcarance of the metathoracic glandular apparatus. 



If the discovery of the odorific glands of the larva3 and pupcie 

 belongs to me (1866), the discovery of the odoriferous gland in 

 these adult Hemiptera was made by Leon Dufour (1833); but it 

 was Leonhard Landois who ascertained the presence of the glandular 

 apparatus in the bed-bug (1868) f. According to him this apparatus 

 consists of two long bursaj, accumulating tlio secretion of a single 

 median gland and gradually uniting in an excretory duct situated 

 in the mesothorax and opening between the posterior legs by a 

 single orifice ! This is all wrong. It consists in reality of a pair of 

 elongated appcndiculate bursae, of equal length, arranged symme- 

 trically on the two sides of the median line, between the cavities of 

 insertion of the posterior legs ; each of these bursce opens by a dis- 

 tinct orifice into a trapezoidal sac which occupies the whole meta- 

 thoracic sternal region included between the line of separation of the 

 mesosternum and metastcruum and the insertions of the third pair 

 of legs ; the base of this sac is bilobed, and presents behind, on 

 either side of the median line, two groups of minute glandular ca)ca. 

 This sac opens externally by a pair of orifices placed in a depression 

 on the sides of the metasternum at the level of the insertion of the 

 third pair of legs ; these orifices are placed on either side of a pro- 

 longation of the mesosternum which extends between the legs. 



To sum up : the bed-bug, from the time of its hatching, in the 

 state of larva and pupa, possesses three dorsal, aljdomiual, odorifer- 

 ous glands, which disappear at the last moult, and are replaced in 

 the adult state by a metathoracic sternal glandular apparatus. The 

 presence of this apparatus is a criterion which enables us to prove 

 that the Cimex has completed its evolution. — Comptes Rendus, 

 July 5, 1886, p. 81. 



* Tliis Ilemipteron, as was seen by Paul Mej'er (187o) and as I have 

 verified, in the larval and pupal states po-'^sesses three abdominal glands 

 which disappear at the last moult when the metathoracic sternal gland 

 is formed ; during very warm and dry summers I have several times 

 observed in individuals collected in the Botanical School of the Museum 

 the simultaneous production of well-formed wings and of the meta- 

 thoracic sternal gland. 



t Zeitschr. f. wiss. Zool. Bd. xviii. p. 218, pi. xii. fig. 14. 



