1891.] . 51 



absolutely certain, that I once saw a J at a gas lamp in spring. But except when 

 searched for in old stone quarries after hibernation has begun, when in some years 

 it occurs plentifully, the species is only occasionally seen at large in this district. — 

 Geo. T. Porritt, Huddersfleld : Januari/ 8th, 1891. 



Fleas in martins' nests. — I very recently obtained two nests of the house-martin 

 {Chelidon urbica), and in picking the clay asunder discovered a number of fleas 

 {Pulex gallince), each in a separate crack, that is, I did not observe two together. 

 As I found theni I placed them in a test tube with some crimped paper to sport 

 on. Into this tube I transferred 178 fleas, and put them in a drawer of my writing 

 desk. The next day being fine, I took them out and placed them in the sun. 

 After a short exposure, the warmth very soon aroused them out of their hibernating 

 inclination ; I presume they thought summer had arrived, for the males very soon 

 began to select their partners ; with some of them pairing only lasted a few seconds, 

 ■which I think probably abnormal, others remained paired longer. I was desirous of 

 obtaining some in this position, but unfortunately had to sacrifice all. I killed them 

 by throwing them into boiling water, and by this means secured seven pairs in cop. 

 I therefore presume that the males and females hibernate, and that the latter are 

 not fertilized until the spring. 



Having examined the contents of the nests of the house-martin, I thought I 

 would see how matters stood with the sand-martin (Cotile riparia) ; in turning over 

 the contents of these nests, about ten days after that of the house-martin, I was sur- 

 prised to see the enormous quantity of fleas in cocoons ; I have no hesitation in 

 saying that the two nests contained upwards of 2000, and I bottled more than 200, 

 but I could not keep pace with their appearance, and consequently had to carry 

 them out of doors into the cold air to prevent them leaping about so freely as they 

 did when indoors in a warm room ; but having been aroused from their winter sleep 

 they still continued too lively, and to prevent their further acquaintance with myself, 

 and fearing they would have a desire to introduce themselves unsolicited to the 

 members of my family, I thought it advisable to plunge them into boiling water. 



In the nest of the house-martin among the lining, which consisted of roots of 

 grass, feathers, &c., I observed several larvse of Lepu^o^ite^-a, apparently those of some 

 Tinea ; these appeared to have first confined their attacks to the pupa-cases of the 

 fleas, for of these I could not discover one ; this may have driven the fleas to seek 

 shelter in the mud cracks of the nest ; but in the nests of the sand-martin the only 

 scavenger I saw was a beetle (a single specimen) and two larvse, which I suppose 

 were those of the same species ; a few Acari were in this nest and also two or three 

 in the former, with a few larvse of the fleas still feeding. The fleas from the sand- 

 martin are very much darker than those from the house-martin, and they may be a 

 distinct species. 



I sent a few of each to Mr. Walker of Liverpool, and in dissecting one he found 



a small Acarus within the abdomen of one of the fleas of the sand-martin. This is 



not the first time that Acari have been found in a ilea ; in a note in " Science Q-ossip" 



for 1871, p. 88, the following sentence appears : — "After soaking (the mole flea) in liquor 



potassce, and squeezing it between two glasses prior to mounting, I was surprised to 



see large numbers of mites expelled from the abdomen, and after I mounted it in 



balsam, I was pleased to find that seven mites still i*emained in the abdomen." 



D 2 



