Some objections to it. 



have taken up the study of mosquitoes solely on account of their 

 importance in tropical medicine, and, in the words of Professor Ray 

 Lankester, "so as to enable the medical men engaged in tracing 

 the connection between mosquitoes and human disease to identify 

 and speak with precision of the species implicated." The ease 

 or difficulty with which mosquitoes can be identified depends, to a 

 great extent, upon the method by which they are classified, and it 

 would therefore have been advantageous to medical men in the 

 tropics if Mr. Theobald had chosen some more marked and more 

 easily recognisable character than scale structure for the foundation 

 of his classification. The three questions which a worker on tropi- 

 cal diseases might reasonably ask when he comes across a new 

 method of classifying mosquitoes are : 



(1) Is the new classification necessary ? 



(2) Will it render the identification of species an easier 



matter than before ? 



(3) Does it bring those species which are alike in habits 



and pathological significance into the same groups ? 



We believe that, as regards Mr. Theobald's new classification 

 of " anopheles," all these questions must be answered without hesita- 

 tion in the negative. 



That the further sub-division of the genus Anopheles (Meigen) 

 is unnecessary, is shown by the fact that in any particular country 

 the number of valid species of " anopheles " is so small that there is 

 no real difficulty in distinguishing between the different species. 

 Even after having worked for only a week or two at the subject an 

 observer easily learns to ascertain the specific name of any specimen 

 of " anopheles " which he encounters. 



As regards the second question, we believe we are expressing 

 the opinion generally felt by medical men in the tropics when we 

 say that the new classification adds much confusion to an already 

 difficult subject, and renders the correct identification of specimens 

 a much more difficult matter than before. We have not yet met 

 any one who could, in all cases, correctly ascertain the generic names 

 of specimens of " anopheles," according to Mr. Theobald's classifica- 

 tion, and the fact that numerous changes have been made in the 

 position of species since the new classification was first instituted 



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