EXPERIMENT STATION BULLETINS. 253 



long as the proboscis in both sexes, and the color is brown or brownish- 

 black. In Gulex, the palpi of the female are less than half as long as 

 the proboscis, while that of the male is as long as the proboscis. Culex 

 rests with the body parallel to the support. AnopJisles is large and has 

 Tery long legs. Beside this it rests with its body away from the sup- 

 port to which it clings. The veins in the wings of Anopheles are cov- 

 ered with black scales and in one species there are four black spots on 

 each wing; in the case of the other species there is a white spot on the 

 wing near the apex. 



By far the most interesting fact known about Anopheles is one 

 recently discovered, viz., that it can and does transmit the germs of 

 malaria from one person to another, thus spreading the disease known 

 as fever and ague, often with fatal results. We are all familiar with 

 the reputation that Michigan used to enjoy before the State was well 

 drained and when pools were everywhere present. It is now believed 

 that the mosquitoes belonging to the genus Anopheles are responsible 

 for spreading the disease wherever it occurs. Of course if the disease 

 be not present the mosquito will not produce it. The germs have first 

 to be obtained from some person already suffering from the disease, but 

 once introduced, the mosquito will spread the trouble. It is even 

 claimed that the infection can be spread in no other Avay. In view of 

 these facts, an experiment was instituted during the. summer of 1902, 

 the object of which was to verify the facts discovered by various experi- 

 menters and to apply remedial measures, as well as to find out any new 

 facts which might come to light bearing on the question. The time 

 chosen for the work proved to be one almost without a parallel as to 

 weather. The summer was wet. Kain fell in abnormal quantities from 

 early spring until fall and for this reason the results have been very 

 different than was expected. The field work was almost entirely done 

 by Mr. Bronson Barlow, and it was owing to his efiBcient work and care- 

 ful notes and observations that the work was rendered possible. 



A glance. at the map will show that the College is a very good place 

 for an experiment of this kind, being adjacent to many marshes and 

 ponds and having several ponds on the campus itself. In planning the 

 work, a large map was first made, on which were indicated all places 

 suspected of harboring mosquitoes. This area was divided into 

 regions and these regions were considered as units. The original plan 

 being to see what could be done for flOO, it was necessary to limit the 

 work to an area capable of being treated for that sum. The remedies 

 used were two in number, viz., petrolizing or treating with some form 

 of petroleum oil, and introducing fish into pounds. The grade of petro- 

 leum oil used was that which was recommended by Dr. Howard and 

 which is known as light fuel oil. It is hoped that a third measure and 

 one far superior to either of the two proposed will be provided for soon. 

 I refer to draining. Draining ends the matter once and for all when- 

 ever it is feasible, and while the surroundings hereabout may not be 

 called wet, still there is a sufficient area of water to stock the place 

 with mosquitoes. As will be shown, it requires but a small amount of 

 water to stock a neighborhood. 



In April, examinations were made of all the ground which was to be 

 covered and as soon as the adults appeared, the ponds were treated with 

 oil. This occurred on April 21. The oil was applied at the rate of one- 

 half gallon to 1,000 square feet or one ounce to 15 square feet. This 



