126 ENTOMOLOGICAL NEWS. [April, 



mentioned at the last meeting had changed to the pupa state 

 on March ijth. He also said that his observations upon mos- 

 quitoes were made in winter, while those of Dr. Howard 

 were made in summer and on a different species ; this might 

 account for the difference in the conclusions to which they 

 arrived. 



Mr. Johnson asked if there was any plant life in the water, 

 and Professor Smith stated that there was quite a good deal of 

 organic matter in the pitcher plant when he collected the mos- 

 quitoes, and all of the contents was placed in the water. The 

 water had not become foul on account of the lack of plant life. 



Dr. Skinner said that many years ago mosquitoes were con- 

 sidered important factors in keeping water pure, but now they 

 are injurious to man as carriers of disease, and the bad proba- 

 bly overbalances the good they do. He spoke about the rela- 

 tion of yellow fever and mosquitoes, and stated that the period 

 between biting and the appearance of the disease was placed at 

 thirteen days. On account of the time taken for the mosquito 

 to become virulent he thought that that the disease might be 

 caused by a proto/oan, and not by bacteria. 



Mr. Wenzel said that a vessel arrived at this port some years 

 ago with a cargo of rags from an infected district, and the 

 disease was spread through the city. 



Dr. Skinner stated that the insects are carried by ships and 

 freight cars to different places, and by biting people would 

 cause yellow fever to appear in districts a long distance from 

 the original source of the disease. 



Mr. Johnson stated that it has been proven that some species 

 of mosquitoes carry disease and others do not. 



Dr. Skinner said that the water supply of Havana had been 

 made much purer within the last two years, but yellow fever 

 exists as violently as before, and this seems to show that water 

 supplies do not carry the disease as much as has been suppose. 



Dr. Skinner exhibited specimens of PsalidoguaiJius fricndii, 

 a beautiful, large, green longicorn from South America. They 

 came packed in a cigar box with cotton and cut cork, and evi- 

 dently had not been killed, as the alimentary canal was full of 

 cotton from the head to the latter extremity, from which some 



