1900J MICROSCOPICAL JOURNAL. 319 



sion. In a few scales this grease causes the scale to ad- 

 here to the cover, thus obliterating the longitudinal marks 

 on the upper slide, and the radiating strife on the under 

 side will then be seen to be perfectly continuous and far 

 better shown than in any other part of the scale. Where 

 only a very little grease is present, or at the edges of a 

 grease patch, little air-bubbles will be seen in some places 

 to follow the grooves between the longitudinal striae, 

 showing the thickness of the latter. As Lepisma may be 

 found on nearly every kitchen hearth at night time, any 

 reader may verify these facts without any trouble. 



Notes on Microscopy. 



F. SHILLINGTON SCALES, F.R.M.S. 



Mosquitoes and Malaria. — The evidence in support of 

 the theory that malaria infection is due to the bites of mos- 

 quitoes, themselves already infected, seems now to have 

 put the matter beyond a doubt. Drs. Sambon and Low 

 have deliberately taken up their residence in the most un- 

 healtliy and fever-stricken spot in the Roman Campagna, 

 a place situated in the heart of the swamp, among the 

 haunts of mosquitoes of the genus Anopheles, and of which 

 the few dwellings near at hand are inhabited by peasants 

 who are constant victims of malaria. These daring in- 

 vestigators have shown that by avoiding mosquitoes they 

 avoid malaria, but a son of Dr. Manson has given an even 

 more striking example of enthusiasm in the cause of 

 science by allowing himself to be bitten by mosquitoes 

 which had been fed on the blood of a sufferer from mala- 

 ria in Rome. The mosquitoes were sent to London by 

 Professor Bastianelli, and received early in July. The 

 patient, after being bitten, developed well-marked mala- 

 rial symptoms, though he has never been in a malarial 

 country since he was a child. He has now recovered, but 

 has thus supplied evidence of the positive kind, as Drs. 

 Sambon and Low did of the negative kind. A letter from 



