38 The Philippine Journal of Science ms 



glands I have done personally in every case. The gut and sali- 

 vary glands were always examined with a high dry lens and often 

 with the oil immersion as well. Sporozoites were examined 

 fresh and subsequently stained with Giemsa or some similar 

 stain, in order to get confirmatory evidence through the staining 

 reaction. I have made fair preparations of the gut also with 

 the Giemsa stain. The gut is opened and spread on the slide 

 as one would stretch a skin on a board for drying. If the gut is 

 spread in a minimum of fluid and just at the moment of drying, 

 the wall of the gut may be made to lie in a single layer and 

 keep its position on the slide. After thorough drying, one may 

 stain as with a blood film. In a proportion of cases one may 

 get preparations in which the cells of the gut and those of 

 oocysts give somewhat the Giemsa values such as are obtained 

 in thin blood films. 



The sieve cages described above are convenient in collecting 

 adult mosquitoes. Insects caught in test tubes are introduced 

 into the cage through the lateral opening, which is easily kept 

 closed with a flap of the covering. Such cages, covered with 

 a moist cloth and placed in a basket, may be carried by rail or 

 motor car for hours with little apparent harm to the insects. 

 The cages may be placed on plates supplied with water and 

 kept there for a day or so until the insects have digested the 

 blood often present in the gut at the time of collection. They 

 are then ready for dissection. 



II. EXPERIMENTAL INFECTION OF MAN WITH MALARIA BY MEANS 



OF ANOPHELES ROSSI 



At the time these experiments were undertaken, there were 

 no infected rossi available of which the larvae had been examined, 

 so that we lack the crucial test as to which type of malaria rossi 

 was used for infecting the experimental cases. However, the 

 evidence points very strongly to type Giles. After feeding in- 

 fected mosquitoes on the experimental cases, the whole lot ex- 

 posed was always examined singly in test tubes and the ones that 

 had taken blood were immediately dissected. By this means it 

 was known what individual mosquitoes were infected of those 

 that had bitten the patient. The sporozoite-infected speci- 

 mens that bit these experimental cases all had the broader type 

 of terminal black band.* 



Further we have seen in part I of this paper that type Giles 



1 Two that bit case 727 had palp ratios of 0.3 and 0.3 — , respectively. 

 The one that bit case 408 had 0.3 (see Table I). 



