OF WASHINGTON. 109 



the character of the country in much of the arid portion of 

 southern California, brought about through irrigation. This, 

 naturally, has resulted in a change in the character of the mos 

 quito fauna and an introduction of new forms. There are por 

 tions of California, however, where it will probably never be 

 possible to irrigate, and where therefore no faunal changes of 

 this character will occur. Mr. Schwarz mentioned the fact that 

 the western part of the San Joaquin valley contains several 

 faunal regions which well deserve an investigation as regards 

 the mosquitoes and other insects inhabiting them. Mr. Currie 

 then spoke of having collected and reared, among other species, 

 Culex tarsalis, Culex mcidens, and Anopheles punctipennis and 

 inacnlipennis at Portland, Oregon, during the season of 1905. 

 Anopheles punctipennis was the common Anopheles in the 

 places where his collections were made, namely, near the Lewis 

 and Clark Exposition grounds. 



The concluding paper was by Doctor Hopkins, and en 

 titled " Statistical Taxonomy." What was meant by this term 

 was explained by Doctor Hopkins and illustrated by a chart in 

 which the statistical method was applied to bark weevils of the 

 genus Pissodes. By a comparison of micrometer measurements 

 of the length of the beak to the length of the thorax and the 

 length of the elytra in a number of individuals of each species, 

 a mathematical formula was obtained which would express the 

 structural proportions of that particular species. Then, by 

 comparing the formulas of different species the relative position 

 of each species in the genus or group would be obtained. This 

 was illustrated in a chart of the species of Pissodes in which the 

 application of this method divides them into what Doctor Hop 

 kins believed to be natural groups. Doctor Hopkins explained 

 in conclusion that this method was used by him as a guide to a 

 natural arrangement of species, but not as a means for their 

 determination and as merely secondary to other characters. He 

 called attention to the progressive development of the beak in 

 Rhynchophora, from the Scolytidse, which have a non-rostrate 

 head, to the species of Balaninus in the Curculionidse, which 

 have extremely long beaks. This elongation of the beak was 

 not, he believed, brought about through use or as a result of 



