182 SUMMARY OF CUERENT RESEARCHES RELATING TO 



emergence of the adult in a week or two. The entire development of a 

 cat-flea occupies but little more than a fortnight. 



Although particular species of fleas are usually associated with but 

 one host, many species pass readily from one animal to another. Rabbit- 

 fleas will pass on to cats, and fleas from many mammals bite man. 

 Twenty fleas — in thirteen genera — have been found on Mils decumanvs 

 and M. rattus und their allies. The common flea of rats in the tropics is 

 Xenopsylla cheopis : the widely-distributed dog-flea and cat-flea {Gtmo- 

 cephaliis canis and G. felis) are common on rats ; the flea most commonly 

 found on rats in Britain is CeratophyUus fasciatus. 



Phototropism of Black Ant.* — 0. Polimanti enquires into the 

 fact that hundreds of winged black ants {Lamis niger) may be seen in 

 Naples in the summer twilight circling around the great arc-lamps, while 

 the lesser lights attract only a few. His view is, that when an ant is 

 illumined on one side by a big light and on the other side by a small 

 one, it automatically seeks a position of equal stimulus on both sides. 

 This brings it always to the powerful light which outshines the others. 

 There is no choice or preference, it is a matter of phototropism pure and 

 simple. 



Ethiopian Species of Prosopis. t — H. Friese discusses the small 

 primitive hairless bees of the genus Prosopis, often called masked bees 

 because of the ivory or yellow marks on the face of the males. They 

 have a cosmopolitan representation, reaching a maximum in Australia. 

 There are about 500 species of Prosopis out of the total of about 8000 

 bees'. They nest in posts and stems, e.g. bramble-stems. The mother 

 makes a silken cylinder at the end of the hole. The food-mass is a 

 viscid mixture of pollen and honey. An egg is placed in the middle of 

 the food -mass, and the mother closes up the cell with a hyaline hd. 

 There is also in many cases a main lid near the entrance to the hole. 

 Friese deals with nineteen African species, six of which are new. 



Journeys of Ants. J — V. Cornetz describes the explorations of ants. 

 They set out from the nest in a straight line and quickly, as if follow- 

 ing a ray ; this initial direction reappears constantly, although the 

 path may turn on itself or make a circuit. There is no particular form 

 of journey, but there is a keeping up of the original direction. The ant 

 neither " seeks its way " nor " finds its way " back. It has a sense of 

 orientation. 



Myrmecophilus Insects.§ — F. Silvestri describes some new inmates 

 of ants' nests. Among these are some Mexican Phoridae — Chonocephalus 

 mexicanus sp. n., Puliciphora inrerta sp. n., a new genus Myrmomyia 

 very near Puliciphora, with the species M. hrachymyrmecis. He also 

 describes a new Milhpede, Myrmecodesmus modestus sp. n., from Jalapa, 

 and a new mite, ApoJselaps mexicmius, from Vera Cruz. 



* Biol. Centralbl., xxxi. (1911) pp. 222-4. 



t Arch. Natur., Ixxvii. (1911) pp. 120-34. 



X Rev. Suisse Zool., xix. (1911) pp. 153-73 (3 figs.). 



§ Boll. Lab. Zool. Scuola Agric. Portici, v. (1911) pp. 172-95 (17 figs.). 



