113 [Assembly 



decim. That so exceptional a life-period is still doubted by some 

 is not strange, in view of the fact that the Cicadas are seen to appear 

 at shorter intervals than seventeen years — indeed, almost every 

 year witnesses their appearance in some part of the United States. 

 But this admits of easy and satisfactory explanation. There are a 

 number of distinct broods occurring within the United States — no 

 less than twenty-one are known — having each its geographical 

 limits, sometimes overlapping one another, but each ever true to 

 its seventeen-year period. Within the State of New York we have 

 five of these broods, one of which made its appearance upon Long 

 Island during the past summer, in immense numbers, and another 

 will appear also on Long Island in 1SS9. 



Besides this seventeen-year Cicada, Prof. Hiley has also discovered 

 the existence of a thirteen -year Cicada. 



No specitic differences in appearance between these two forms 

 can be discovered, for which reason the latter is not accepted as a 

 distinct species, but is regarded only as a form or race. The thirteen- 

 year Cicada is a southern form, which in its northern extension does 

 not reach further than into the southern part of Illinois. We do 

 not have it in the State of New York. 



In the possibility that this short-period southern form may, in 

 the lapse of time, have been developed from the normal seventeen- 

 year race, as a consequence of the higher temperature of the 

 Southern States hastening its development, Prof. Riley has, the 

 present year, undertaken to test the effect of climate on the per- 

 manency of the two races, by transferring them from one region to 

 the other. He thinks it possible that a southern brood brought 

 northward might fail to appear at the expiration of thirteen years, 

 and a northern brood taken south, might appear in a less time than 

 seventeen years. 



Offering to him my assistance in the interesting experiment, he 

 sent to me a quantity of apple twigs from Mississippi, tilled with 

 the eggs of the thirteen-year Cicada, with the request that I would 

 place them in an orchard where the result of the experiment could 

 bo observed at the proper time, and that I would also have proper 

 record made of the same. 



I, therefore, ask place in some publication of the Institute, for the 

 statement that the orchard of Mr. Erastus Corning, at Kenwood, 

 was selected for the planting of the eggs, from the considerations 

 that it was a young orchard, that it promised permanency for the 

 desired time, and that no other brood of Cicada would occur there 

 with which tiiis could be confounded. The tree beneath which the 

 eggs (they were hatching at the time when the twigs were placed 

 about the base of the tree, and tied to its branches) was marked with 

 a zinc label, bearing this inscription : 



"Thirteen-year brood of Cicada (Riley's Brood, No. YII) — eggs 

 from Oxford, Mississippi, planted July 4th, 18S5." 



Additional eggs from a second sending were placed beneath the 

 same tree on July 2l8t, and also some in a wood adjoining, a few 



