XVI. ABSTRACT OF PROCEEDINGS. 



the body of an insect and then develope, after introduction into 

 the body of the dog. A puppy, who ate 110 Stomoxys flies gorged 

 with filariated blood, in one month shewed after a series of experi- 

 ments, extending over nearly a year, that such an hypothesis was 

 untenable ; and moreover, that the time taken by the young 

 filaria to arrive at sexual maturity was not less than seven months 

 nor more than twelve. After discussing Grassi's discovery of the 

 intermediary host of Filaria immitis, viz., the Anopheles maculi- 

 pennis, Meigen, syn. A. claviger, Fab., and the statements of a 

 paper by Grassi and Noe on ' the propagation of the filariae of the 

 blood exclusively by means of the puncture of peculiar mosquitos,' 

 the author states we are now able to give an exact account of the 

 life-history of both Filaria nocturna, and F. immitis. The 

 sexually mature worms in man or dog, produce embryos, which 

 swim in the blood : the mosquito on biting abstracts some of the 

 embryos, these develop in the mosquito's body, and in about three 

 weeks are capable of entering their final or definitive hosts, passing 

 into the puncture made by the mosquito in the skin ; they then 

 advance to sexual maturity in the course of about a year. The 

 position in the mosquito's body during the metamorphosis of the 

 embryos distinguishes F. nocturna from F. immitis, the former 

 being in the thoracic muscles, the latter in the malphighian tubes, 

 at their maximum development : the later are distinguished as 

 being shorter and thicker. It has been learnt that mosquitos live 

 for long periods and not merely a few days as was formerly sup- 

 posed, and that during their life they bite frequently. In Europe, 

 Anopheles maculipennis plays the role of host for the malarial 

 parasite, for F. immitis and it is believed also for F. nocturna: 

 in Australia the house-mosquito, Culex skusii, Giles, is host for 

 both F. nocturna and F. immitis, and probably also for the 

 malarial parasite. 



3. "Two historical notes in regard to Captain Cook the Circum- 

 navigator," by J. H. Maiden, Government Botanist and 

 Director of the Botanic Gardens, Sydney. 

 Students of Australian history will remember that as regards 

 the death of Captain Cook, besides stabbing him with a dagger, 



