210 MOSQUITOES 



blue g-um occurs no otlier remedy need l>e sou.ulit for. 

 Further than that, he stated that no matter liow pk-ntitul 

 the mosquitoes are, a few twigs or leaves laid on the pil- 

 low at night will secure perfect immunity. The same year, 

 Mr, W. A. Sanders, of California, wrote that he had planted 

 eucalyptus trees nineteen years previously about his 

 house and that i\\e\ had reached, some of them, a height 

 of 140 feet. An irrigating ditch ran through the g)'()V(% 

 but there was never a single mosquito larva in the ditch 

 in the grove, although on both sides of the grove larviic 

 were plentiful. In the g-rove, mosquitoes were never 

 found, though outside they were plentiful. This seems 

 very strong evidence, but there is also evidence to show 

 that eucalyptus trees are not at allcflective. Dr. Alfredo 

 Dugcs, the well known naturalist of Guanajuato, Mexico, 

 wrote me on September 8, 1900 : " I have received your 

 very interesting study of the mos(piitoes of the United 

 States, and thank you greatly for it. At the end of the 

 book you speak of the utility of eucalyptus for driving 

 awaj' insects. I have had some experience with these 

 trees. The fresh leaves placed upon the pillow Avill 

 attract mosquitoes. Thinking that the mosfjuitoes loved 

 this plant, I have ])laced i\\o branches farthci- away, but 

 without result. I have burned the halves in my chainl)er, 

 and the cui'sed beasts have n^sisted the smoke." Dr. 

 Nuttall states that malaria still i)r('vails in certain local- 

 ities outside of Rome, in sjjite of eu(alyi»tus jilantings. 



