IMiKEliDINCi OF JUNOMA COKMA INDliK 



iiiGU ti:mpi;kah Ki:s niKorciii 



TWl-MV -TWO SI CCKSSlVi: 

 GEN 1- RATIONS 



WILllKLM SCIIHAUKU 

 I,()8 ANOEI.ES, TAI.. 



Hrccdiii); liiitt<r(liis in luit .iiiii lold tiiii|«ratiiris is mil a new idea, (icniiaii 

 I'litoiiiiilo^ists, ('.specially, havi- cxpcriiiK'Htt'd in that line fur many years, and 

 have piililishi'd their experiments, and I have no duiiht they will be followed by 

 many interested entomolojjist.s, who have the time and Jjatienee. I hope that my 

 little experieiiee puMished here, will interest others in joining me in this njost 

 interestinj{ work, in which, to obtain In-st results, many students of widely separ- 

 ated regions must co-operate. 1 wish to thank Mr. Fordyee (irinnell, Jr., of 

 Pasadena, C'al., for his valuable help. 



In the spring of the year l<)(t() 1 sowed some seed of I.inaria ri/mlxilnria, a 

 little trailing plant, which is very useful for rockwork, and found later on this 

 plant some caterpillars, at that time utiknown to me. I gathered all I could lind, 

 and obtaiiud later sixteen chrysalides. As I had contemplated for some time prior 

 to try some temperature experimenls, I bought a little chicken incubator, and bri'd 

 the chrysalides in yi) degrees warm, damj) air, and in darkness. After five days the 

 liutti-rHies emerged, and they were all our \vell-ki\own Junonia coenia. I noticed 

 that all were somewhat dark in the ground color. However, I was disap])ointcd. 

 .\s is the case with all experimental work, we connnonly expect great things, so 

 nuich the more when we read condensed accounts of what other experimenters 

 have accomplished. Yet it is a great thing to have patience to try things out, 

 so I figured that all our thousands of different sj)ccies of butterflii's were not 

 made at once ; they must have developed by the slow process of evolution. 



.Vnybody who is interested in insect life will have marveled how quick the 

 transformations from the egg to the imago take place in nature. In the summer- 

 time with us, this cycle is repeated once, and by some butterflies twice. However, 

 what will our readers say, to hear that by the use of artificial warmth, I was able 

 to breed from the first generation in A|)ril, 1{)09, to November, lyil, that is, 

 within two years and seven months time, twenty-two successive generations; and 

 by keeping the citerpillars in 80 to <)() degrees temperature day and night, I 

 succeeded, in a few generations, in finishing a comj)letc cycle in one month. This 

 could not be kept up as trouble arose with contagious diseases. Other experi- 

 menters have made tem))erature exiu-rinients, by breeding butterflies in artificial 

 temperatures, hot as well as cold, and we have learned many new facts; yet 

 there is still much to learn, as almost every experimenter formed a somewhat 

 different theory, as to why these changes in color and markings, from the winter 

 to the sunnner generation, take pl.ace. I have not heard that any cx])erimenter, 

 here or abroad, has succeeded in breeding from his own stock of butterflies at any 



