274 [September, 



in some part of the country every year. Assuming all that part of North America 

 in which it has ever been observed to be its zoological province, how are the 

 sub-provinces and different times of appearance to be accounted for ? Are all 

 those sub-provinces to be regarded as the theatres of independent creations ? Do 

 the facts demonstrate that the same species may exist in provinces which may be 

 presumed to have had different eras of origin ? 



It would be a curious fact, and one of important application, that exactly the 

 same species can inhabit provinces having independent creations, and if, too, as 

 in the case of this insect, it should be clearly impossible for it to have extended 

 from one province to another. 



Or, can it be possible that every distinct district in which the Cicada appear 

 is really an entomological province, and that entomological provinces in this part 

 of North America are quite restricted in extent, as has been observed by Dr. 

 LeConte in California ? (Communicated by that gentlemen to the American 

 Association for the advancement of Science at its meeting in August, 1851.) 



Those sub-provinces may have relations to geologic changes. Having the ex- 

 traordinary characteristic necessity of remaining in the earth for seventeen years, 

 as a fact in the history of this insect, may it be possible to infer that geologic 

 changes have effected the difference in the times of its appearance, or that so short 

 periods as fractions of seventeen years have been of geologic importance through- 

 out the range of the Cicadas? 



The Cicada sejjtendecim has appeared in the vicinity of Philadelphia, at inter- 

 vals of seventeen years, certainly since 1710. There has been, it aj)pears, no 

 variation of temperature, nor causes accidental nor other since that date sufficient 

 to affect its habits in any perceptible degree. It is stated in Clay's Svi^edish 

 Annals, to have appeared in May, 1715, in this neighborhood, (which, so far as I 

 know, is the earliest authentic record ;) punctually in the same month, every 

 seventeenth year, now certainly for nearly one hundred and fifty years, has this ex- 

 traordinary insect been known to make its visit. No causes have affected it 

 during that period, not even so far as relates to the month in which it appears. 



Passing, I would observe that so far as relates to the neighborhood of Philadel- 

 phia, the Cicada septe^idecim clearly had not a fair start with the year 1, anno 

 mundi of the commonly received chronology. If it had had, the sum produced by 

 1851-f--1004 1 ought to divide by 17 without a remainder, which it will not do, 

 more insignificant facts than which have troubled schoolmen. 



I have never seen any animals moie entirely stupid than the seventeen year 

 Locusts. They make no effort to escape, but allow themselves to be captured 

 with perfect passiveness, thus reminding one of the tameness of animals in coun- 

 tries where they are not molested by enemies. All animals of as high grade of 

 organization as these insects, acquire instincts from impressions made by the 

 presence of danger and otherwise, which they transmit to their offspring. The 

 young Fox of to-day is undoubtedly superior to his juvenile progenitor of a cen- 

 tury since. The cicada have acquired no such instinct. Their short life of matu- 

 rity above the surface of the earth, does not appear to be of sufficient duration for 

 such to be formed and impressed on their posterity. 



In short, it appears to me that the study of these insects, and the examination 

 of their separate ranges, might result in conclusions of extraordinary importance, 

 especially relative to modern views of the distribution of animals. No animal is 



