1900] MICROSCOPICAL JOURNAL 289 



came received in the system of the mosquito, in the juices 

 of which it formed more blastocytes. Major Ross remark- 

 ed parenthetically that he was warned by Prof. Herdman 

 to be very careful as to the terms he used, and he there- 

 fore said ^juices of the mosquito," and not "blood of the 

 mosquito," though he was convinced that the juices cir- 

 culated. The blastocytes multiplied within the mosquito 

 exceedingly, and were to be found even in the head. At 

 the lower side of the head were found a number of ceils, 

 which he had discovered to be the salivary glands of the 

 creature, and in these the blastocytes were also to be found. 

 A mosquito thus affected, in biting a person deposited in 

 his system a blastocyte, and the seed was sown for the 

 malaria. To prove that the mosquito was the means of 

 ihe conveyance of the disease, Major Ross said that two 

 forms of gnats or mosquitoes were found in England. The 

 common one was that known as Culen, and the less com- 

 mon was Anopheles. The larvae of Culex were well known, 

 and one could not place a tub of water in his garden and 

 allow it to remain there for a few weeks in the summer 

 without finding the larvae of Culex wriggling about in it, 

 and sinking suddenly to the bottom when the water was 

 disturbed. These larvae were provided with an air tube, 

 and hung head downwards from the surface. The larvaB 

 of the Anopheles were laid in pools of water or in wet 

 soil, and they were without the air tube, and lay full length 

 upon the surface of the water. All the Anopheles which 

 were found in England were capable of conveying mal- 

 aria ; but it was, of course, owing to the extinction of the 

 malarial parasite, very difficult for the mosquito himself 

 to become infected. It was necessary for people to dis- 

 possess themselves of the idea that these creatures only 

 lived for an hour or two or a day or two. He had kept 

 them alive for a month in tubes, in the most artificial way, 

 and other observers had kept them alive for six weeks, 

 feeding them only on bananas. His own, and he had 



