APPLIED SYSTEMATICS — SCHMITT 331 



farflimg inspection service at all ports of entry and at border stations. 

 IndicatiA^e of the importance that the Department attaches to the 

 necessity of having all "immigrants" of agricultural import promptly 

 identified is the fact that it maintains insect, plant, and phytopatho- 

 logical identification services. The division of insect identification, 

 located in part in the National Museum in Washington, comprises a 

 staff of about 40 entomologists and technical assistants, and elsevrhere 

 in the Department an equally alert staff of taxonomic botanists and 

 plant pathologists. They handle many thousands of identifications 

 each year and in the course of making them have detected many 

 harmful insects and other forms of life which might otherwise have 

 become seriovis agricultural pests. 



EPIDEMIOLOGICAL APPLICATIONS 



Malaria ranks as one of the great scourges of mankind. We hear a 

 great deal of tlie wonder drugs developed to overcome it, but very little 

 of the role that taxonomy played in furthering its control. From the 

 time that Ross first discovered that the causative parasites were 

 transmitted by anopheline mosquitoes, it was thought that the problem 

 could be solved quite simply by a reduction of the mosquito popula- 

 tion — by treating their breeding places with larvacides, by introduc- 

 ing the little mosquito-eating fish Gambusia., by clearing out aquatic 

 vegetation, and by drainage. The results in the States, and in Panama 

 in the course of the construction of the Canal where expense was 

 no object, were most gratifying, but when the Rockefeller Foundation 

 tried to apply these methods in southern Europe, the same successes 

 Avere not achieved. The carrier abroad was a different species, to 

 be sure, with different habits and capable of breeding at the edges 

 of running water, where its North American congener was a pool 

 breeder. Nevertheless, it was impossible to establish any correlation 

 between the incidence of intense malaria and the relatively few 

 anophelines found in houses. On the other hand, there were localities 

 with incredible numbers of the anophelines, tens of thousands in a 

 single stable, and no malaria whatever; there were swamps without 

 malaria, and a great deal of malaria without swamps. 



It was not until two important and, at the time, unrelated discov- 

 eries were brought to bear on the problem that the apparent anomalous 

 behavior of the common malaria mosquito abroad was cleared up. 

 The first was the precipitin test, permitting the exact identification of 

 blood, both human and animal, a serological and purely toxonomic 

 procedure by means of which, no matter where a mosquito was lurking 

 at the time of its capture, its host or hosts could be determined. The 

 other discoveiy, which to my mind is one of the most important dis- 

 coveries in the history of malariology, and certainly in its European 



