QUEKETT MICROSCOPICAL CLUB, 349 



than the stopper, with a piece of filter paper on it. The eggs will be 

 laid on the paper. The bottles should be kept in a dark cupboard, 

 and on the first or second day the males will be found dead on the 

 paper. Mosquitoes may be fed on dates, raisins, bananas, or 

 blood. By means of diagrams Dr. Tierney then pointed out 

 various details of the anatomy of mosquitoes, and described his 

 method of dissection. He uses two straight surgical needles, 

 which have sharp edges, and dissects in | per cent, salt solution. 

 The insects should be kept until the stomach is free from blood — 

 i.e. when the ventral surface is free from blackness. They are 

 best killed by concussion, which is effected by shaking them up in a 

 test-tube. The viscera are removed by making a nick each side 

 as near the tail as possible, then steadying the thorax with 

 one needle, while with the other the tail is drawn away, bringing 

 the viscera with it. The salivary glands are obtained by pulling 

 off the head in a similar way. The biting mechanism was 

 illustrated and described, and Dr. Tierney then passed on to the 

 consideration of the development of the malarial parasite. The 

 life-cycle of the parasite is passed partly in the human host and 

 partly in the body of the adult mosquito. The malaria Plasmo- 

 dium is never passed on by the female mosquito to her offspring. 

 In the tropics, where human reservoirs and mosquitoes abound, 

 there is no break in the life-cycle. In temperate zones the con- 

 tinuance of the cycle depends upon three factors : (1) The period 

 of temperature high enough to incubate the plasmodium in the 

 body of the mosquito ; (2) the period during which the organism 

 can linger on in the system of the human host ; (3) the prevalence 

 of mosquitoes when recrudescence occurs. Dr. Tierney said that 

 two-thirds of the preventible diseases in the tropics are insect- 

 borne, and that the conquest of the tropics involves the conquest 

 of insect-borne disease. Human civilisation advances only as far 

 as our knowledge of the role which insects play in the dissemination 

 and transmission of disease, and this role is not confined to the 

 tropics. Our own house-fly, flea, bug, mosquito, etc., all play an 

 important part, and are equally dangerous in their spheres. The 

 meeting closed with a hearty vote of thanks to Dr. Tierney for his 

 lecture. 



At the 567th Ordinary Meeting of the Club, being also the 56th 

 Annual General Meeting, held on February lith, 1922, the Presi- 



