I'H 



iiOST )\ ZOOLOGICAL SOCIETY. 8. 



the siinie group of phints a?^ the potato. When on account 

 of the caltivation of the laud, the potato hegau to take the 

 place of the weed,;, the beetle was obliged to ehauge its food- 

 j)laut aud c*ousequeutly- chose the potato as beiug closely al- 

 ii .'d to its forui'ji- ()uc. Tlxei-e is another iuterestiiig- fact whicli 

 is likewise prove(l by thip'f ami liar, alas too famihar insect. , 

 It is a noticeable fact that man both in historic and prer' 

 historic a.!:cs has always h.id the tendency to migrate west.' 

 We know thatT^i^' Hlins;''i8dythians and most of the other 

 ha]'l)arians that o"\4^rthrew-the Roman empire were of Orien- 

 tal origin, and, aetording to iiistory, i^tarted their migrations 

 from what is nowTartary in kllLsia, In yet more modern 

 tunes, it was west that our f oreyf athers sailed and it is still 

 west that the tide ol emigration rfqws . This, however, is exnct 

 Iv tlie reverse in insects and thelo'wef* animals in ironeral. 



With tiiem the general tendency is to migrate east. It 

 is east that our former fiend tlie Colorado potato-beetle 

 has been migrating.'-'' ■ Itis east tlmt the chinch-bug ( blissus 

 LKU(T(n»TERiTs) is noW) moving Jind; probably it always will he 

 cast that insects will migrate. • )j V: = ; r 



(•)f course thei*e ai*c excvptions to the general rule, both iii 

 man and insects. However it iB these exceptions which add 

 s!r([ingth to the^ rule. As An exatnple, in man, Ave find that 

 the North Amciican Indians have nipved east; since accord- 

 in j^ to the pveseut theory, their race originated in Xorth-east- 

 «'rn Asia. ' There are likewrse exceptions among insects; as 

 European speciesf being tountl in this country and New Eng- 

 lantrspccies Ix^ing tiiken on th<6 Pacific coast. But such oc- 

 currences ai'e i-are !(nd niu'sfhe ^'onsirlered only as exceptions. 

 1 could iill several j>ages \\'\{\\ remarks on the migiaticm 

 of insects, h^i.t I have neither liine nor space and consequently 

 nuist close Jjii^se Uiief. remaiks with the hope of having the 

 pleasiue, Ai some futuie date,' of contributing^ to the Journal 

 another ;uti<de^()n the same subject. ^ 



* rh«» .spt'ou's ri\ At'ci %:.\!it jit tli(> rateof seventy miles a yet^i{ and ie> iiowlound oven in Kiirope. 

 t \|,jhi)iUue f .-st>r. A.lhnf'tarjifs, Aiithrf'nusgcr<)phulariae,etc- ' ' 



