234 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



history, habits, and development that interest the large farmlEff con- 

 stilueucy to which this annual report is addressed. In doiufr this v.-e 

 shall reproduce some passages of the bulletin referred to, placiug tlie 

 passages in quotation marks. We shall also quote irom some of our 

 writings on the subject at the time the insect was appearing. 



A SEVENTEEN- YEAR AND A THIRTEEN-YEAR RACE. 



In 18G8 the writer announced the existence of 13-year broods of this 

 insect, in addition to the 17-year broods, one of which has been veiy 

 thoroughly recorded ever since the earlier i)art of the seventeenth cen- 

 tury. At the time we made this announcement in the Journal of Agri- 

 cidture of Saint Louis, for June, 1868, we were not aware that any one 

 else had made similar observations. Four months later, however, we 

 learned, as stated in the First Annual Eeport on the Insects of Missouri, 

 that Dr. Gideon B. Smith, of Baltimore, 3Id., had made similar discov- 

 eries, though he had never published the facts, which had been collected 

 in an unpublished manuscript. This had been hindly copied for us by Dr. 

 J. G. Morris of the same city. As set forth in a note to Bulletin 8 (pp. 

 5, G) we became aware, five years later, that Dr. D. L. Phares, of "Wood- 

 vllle, Miss., had even anticipated Dr. Smith in this discovery, in so far 

 as one of the broods is concerned, and from correspondence with Dr. 

 Phares, as well as from personal interviews with him on the subject, it 

 would appear that Dr. Smith really obtained his information from Dr. 

 Phares. To the latter, therefore, belongs the discovery of one of these 

 13-year broods of the Cicada, and the credit of having first published 

 the facts, though, unfortunately, no record of the publication other than 

 his own memory is now to be obtained. 



TWO DISTINCT FORMS OR VARIETIES ; SPECIFIC VAEUE OF THE DIF- 

 FERENT FORMS. 



" It is not a little singular also that two distinct forms occur in both 

 races — a large one and a small one — the former by far mere numerous 

 than the latter. This fact has been observed in f^ast years, and was 

 noticed in 1868 by independent observers in different parts of the 

 country. Indeed, it was observed by Dr. Hildreth, of Marietta, Ohio, 

 as far back as 1830 {vide SilUman''s Journal, xviii, p. 47). The true 

 Cicada sepiendecim of Linuaius (PI. YI, Fig. 1 A, ventral view of male), 

 as described by Harris and Fitch, occurs in the greatest numbers, both 

 in the 17- and i3-year broods. It will measure, on an average, 1^ inches 

 from the head to the tip of the closed wings, and almost always expands 

 over 3 inches. The whole under side of the abdomen is of a dull orange- 

 brown color, and, in the male more especially, four or five of the seg 

 ments are edged with the same color on tiie back. 



" The other form (PI. VI, Fig. 1 B, ventrnl view of male) is not, on an 

 average, much more than two-thirds as large, and usually lacks entirely 

 the dull orange abdominal marks, though there is sometimes a faint trace 

 of them on the edges of the segments beneath. This small form was de- 

 scribed in 1851, by Dr. J. O.Fisher, in the Proceedings of the Philadelphia 

 Academy of is'atural Sciences, vol. v, pp. 272, 273, as a new species of 

 Cicada, hitherto confounded with sejjtcndccim, and was named Cicada 

 cassinii. His description was followed by a note from Mr. John Cassin, 

 in which the latter states that the two forms show no disposition to 

 associate together, and produce very different cries- The fact of the 

 yery great difference in the song of the males has been fully confirmed 



