474 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Ai-thropoda. 

 «• Insecta. 



Structure of Rat-flea.*— E. A. Minchin describes some of the 

 structural details which he has observed in Ceratophyllus fasciatus Bosc. 

 in the course of many dissections. He describes in detail the method 

 used, which takes advantage of the adhesion of the soft parts to the 

 cover-glass. The nervous system is different in the two sexes, the male 

 having seven free abdominal ganglia, as against six in the female. 

 There is also a difference in the arrangement of the nerve-stems given 

 off from the hindmost ganglion-mass. The salivary glands of the larva 

 differ greatly, both in size and in complication of parts, from those of 

 the adult flea. In the more or less omnivorous larva, which feeds largely 

 on the faeces of the rat and on dirt and debris of all kinds, the salivary 

 glands are larger and with greater secreting activity. The glands of 

 the adult, whose secretion probably keeps the blood from coagulating, 

 contain microbes which perhaps cause the itching after the bite. The 

 genitalia of the male exhibit a singular complication of parts, but can 

 be readily mounted as an entire preparation from testes to penis. An 

 account is given of the reproductive system in both sexes. Attention 

 is called to'the presence of stellate muscle-cells forming a beautiful and 

 very delicate muscular network on the wall of the oesophagus, such as 

 also occurs on the "crop," or "sucking-stomach" of the tsetse-fly, and 

 on the crop of the house-fly. Perhaps the ancestors of fleas had a crop, 

 of which the network of stellate muscle-cells on the oesophagus is a 

 residue. 



Abdominal Hairs in Bombycidse.-f— Leopoldo Chinaglia describes 

 the hairs of a tuft on the posterior abdominal segments in the females 

 of some Bonibycidse {Euproctis chrysorrhcea and Lymantria dispar). 

 When the eggs are being deposited, the female covers them with a 

 cotton-like investment of detached hairs, and they are thus very 

 effectively protected against the inclemency of the weather. The form 

 of the investment is specific — irregularly globose or sub-ovoidal in 

 Lymantria dispar, elongated and ellipsoidal in Euproctis chrysorrhcea, 

 and the shapes of the hairs are also specific. Those of the last-named 

 species are carefully described. They include some remarkable spinose 

 forms, like twigs of briar, with the points of the spines directed towards 

 the apex. The adaptations of the various kinds of hairs, to adhere to 

 the eggs, to separate off from the mother-moth, and to form a sort of 

 web, are explained. It is interesting to find that in the male Euproctis 

 the abdominal tuft is slightly different in shape and size, and is formed 

 of quite different kinds of hairs and elongated scales and transitions 

 between the two. 



Malpighian Tubes in Lecanium.J— G. Teodoro describes the struc- 

 ture of the Malpighian tubes in the females of Lecanium oleae, L. 



* Journ. Quekett Micr. Club, xii. (1915) pp. 441-64 (7 pis.). 

 t Redia, x. (1915) pp. 1-6 (2 figs.). 

 \ Redia, x. (1915) pp. 15-19 (1 fig.). 



