64 SUMMARY OP CURRENT RESEARCHES RELATING TO 



would designate R. asetifera. He notes the interesting fact that in 

 those Hemiptera which live on the more readily flowing juices of 

 animals, the pump is less developed ; and this reduction of salivary 

 functions may go so far that in Cimex hydrometra, for instance, the 

 lower maxillary tube, usually of exclusively salivary function, may 

 fuse with the upper suctorial one. 



(e) Glands. After describing the salivary glands, Herr Wedde 

 notes the position and nature of other, hitherto unobserved, glandular 

 masses, one situated where the narrowed anterior end of the pharynx 

 passes into the upper maxillary tube, and two smaller ones lying 

 between the exit canal of the pump and the chitinous band which 

 fixes it. As to their function, he suggests that they secrete an oily 

 fluid, diminishing the friction of maxillse, mandibles, &c. 



(/) The ascent of the nutritive fluid, after the wound has been made 

 and the flow stimulated by the salivary secretion, is effected by the 

 above-mentioned dilatation of the pharynx, a return flow being pre- 

 vented by the successive slackening of the dilator "muscles and con- 

 sequent re-narrowing of the pharynx from before |back wards. The 

 ascent is also essentially aided by capillary action within the long 

 maxillary tube. 



Anatomy of the Mallophaga.* — Dr. F. Grosse deals principally 

 with an account of a new species of Tetrophthalmus (T. chilensis), 

 taken from a pelican in Chili. The anatomy is systematically discussed. 



The head and the mouth-organs are first described ; the statement 

 of Melnikow that the labium is a provisional structure which falls 

 away at the ecdysis, is explained by the supposition that he examined 

 forms just after ecdysis, in which the parts being thin and mem- 

 branous might be overlooked ; a labium is certainly always present. 

 The thorax and the legs are next described ; the male is provided 

 with tarsal lobes and spinous setse at the end of the tibiae, by means 

 of which it is able to hold the female. As in the other Mallophaga, 

 the abdomen varies in form with the sex ; while the female has ten, 

 the male has only nine segments externally. Kramer's results on the 

 histology of the enteric tract are summarized, and the author makes 

 some additions based on his own observations ; from the structure of 

 the pharyngeal skeleton the author concludes that it is not adapted 

 for sucking, but for seizing and taking up the particles of feathers 

 among which it lives ; the buccal cavity has the same histological 

 character as the integument ; the roof is thick- walled and folded longi- 

 tudinally ; in some genera a group of long flat backwardly diverted 

 teeth are to be found in its lumen. These prevent the particles of 

 feathers from passing into the stomach before they have been properly 

 softened and broken up. Dr. Grosse denies to the chyle-stomach the 

 lining of chitin which was ascribed to it by Kramer. With regard 

 to the food of the Mallophaga, he states that, though he has examined 

 a large number of forms, he has found blood in the intestines of but 

 few ; but in such cases, as in one he was able to observe, the skin of 

 the bird had been injured, and there was coagulated blood among the 



* Zeitschr. f. Wiss. Zool., xli. (1885) pp. 530-58 (1 pi.). 



