244 



(8) April 28, 1890, a large lot of grabs was collected from a field of 

 growing corn 3 miles west of Champaign, 2 or 3 acres of which had been 

 completely destroyed. The next day ninety-three of these grubs were 

 put into the trench cage. This lot of larvse was examined May 31, June 

 23 (at which time five were separated for more frequent observation), 

 and July 1 and 2, the larvae all continuing active until the latter date, 

 at which time one was shortened in its earthen cell. This larva was 

 separately watched, and found dead, as a pupa, July 18, July 15 and 

 18, no pupse had appeared in either of the oth^r lots, but July 24 two 

 of the five, separated as above, had pupated, two others had formed their 

 cells and shortened up, and one was dead. August 5, these were all 

 dead without further change. In the main lot, the first pupae were 

 found July 25. August 12, larvae and pupae were seen, but no imagos, 

 and September 4 the cage contained several dead pupae and two adults 

 of rugosa, four more of which were taken out September 26. 



(9) In a compartment of the breeding trench, just described, in 

 which no grubs were put, two pupae and one larva were seen July 24, 

 (apparently having made their way under the partition from a cage 

 adjoining,) and September 25, two of these were beetles of L, inversa^ 

 and one was a pupa of the same species. 



(10) Collections made September 15, 1890, from the same field from 

 which the larvae were taken in April for the above experiments, were 

 all larvae and adults (no pupae occurring), the latter both rugosa and 

 inversa. 



Generalizing the above breeding-cage experiments, we learn that 

 pupae Lachnosterna impUcita, inversa^ rugosa, Mrticula, and gibbosa have 

 been found by us in the earth from June 28 to October 9, but not earlier 

 and not later ; and that imagos of these species have occurred in the 

 same experiments from September 5 (their earliest noted appearance 

 there) to October 9, beyond which date the breeding-cage work was not 

 continued. 



The dates at which the adults of Lachnosterna have been observed 

 by us in the earth outside bear out in every case the manifest teaching 

 of these breeding-cage results. L. fusva we have found as an imago, still 

 in its pupal cell, August 11, October 25, November 28, March 24 and 

 28, April 1, 2, 4, 5, 8, 9, 10, 11, 12, 14, 15, 16, 21, 23, and 27, and May 

 1. L.fraterna, June 6; gibbosa, August 11, May 6 and 8; hirticula^ 

 August 12, March 27, April 5, and May 1 ; iliciSy only April 12 j inversa^ 

 October 28 and March 27, April 2, 4, 5, 8, 9, 12, 14, 15, 16, 20, 21, and 

 May 8; rugosa, September 15, October 28, March 24, and April 22 and 

 23 ; tristis, March 28, April 8, 12, 14, 16, 20, and May 1 and 16 ; arcuata 

 we have taken from the earth only December 4. 



Taking into account, now, the fact that in all our collections of these 

 imagos, extending through five years, not a single pupa was discovered 

 except in the interval between June 28 and October 9, as stated above, 

 we see that all the observations made by us on the transformations of 



