35f 



the lingua ; it Has not been possible, however, to detect 

 the point where they open into the buccal cavity. AYillem, 

 who has specially studied these glands, states that in 

 SiJiiiithunis their ducts open on to the lingua on either 

 side. He remarks as follows: — " Le conduit en c^uestion 

 se rapproche de la ligne mediane de la tete en passant 

 contre le pivot de la mandibule, puis cotoie obliquement 

 la commissure perioesophagienne ; sa derniere portion, a 

 parol chitineuse plus epaisse, est logee dans une rigole de 

 la base de riiypopharynx ; elle aboutit dans la cavite 

 buccale sur le cote de cet organe, un pen au-dessus de la 

 region occupee par le bord superieur de la plaque molaire 

 de la mandibule "' (26, p. 655). According to him a 

 similar arrangement prevails in Orchesella. 



The salivary glands are regarded by Willem as being 

 a pair of metameric glands pertaining to the first maxillae, 

 and he bases this conclusion on the embryological 

 researches of Lzel (38). He remarks that *' Morpho- 

 logiquement, on doit les considerer comme des glandes 

 metameriques appartenant an segment de la premiere 

 maxille : la partie de I'hypopharynx ou aboutissent leurs 

 conduits excreteurs se forme, en effet, an se depens d'une 

 protuberance mediane qui apparait chez I'embryon sur le 

 premier segment maxillaire." If this observation of 

 Uzel be confirmed, the important generalization that the 

 salivary glands of the Collembola are homologous with 

 the shell glands of the Crustacea would be evident. The 

 Crustacean shell glands open on the second maxillary 

 segment, and it will be seen on referring to the table 

 given on page 74 that the second maxillge of the 

 Crustacea are homodynamous with the first maxillae of 

 insects. 



Of the two pairs of glands which open into the 

 ventral groove, the most important pair are known as the 



