CROSSING EUSCHISTUS VARIOLAEIUS AND EUSCHISTUS SERVUS. 345 



June llth to July 16th — this pair did not mate, and dui-ing this period eggs 

 were deposited six times, whereas normally eggs are deposited only once or 

 twice between two matings. This female deposited eggs 20 times, and 

 mated only 4 times, wheareas normally mating occurs more frequently than 

 the deposition o£ eggs. These facts suggest that a more normal proportion 

 of the hybrid eggs might have been developed if the matings had been 

 normal. Whatever condition exists that interferes with the matins: of these 

 two species, it is evidently not due to the fact that either the male or the 

 female was functionally inactive, for the female deposited the normal 

 number of eggs at normal intervals, and the male, when temporarily trans- 

 ferred July 2nd to a cage containing three female servus, mated the same 

 day with one of his own species^ and continued to mate for 42 hours. 

 Further, he had mated with his own species before being caged with the 

 female variolarius. July 2nd, we placed a few fresh wild servus males in 

 Cage 2, but the variolarius female did not mate again, and died, July 16th. 



Of the 32 F. 1 hybrid nymphs from this pair, 27 were reared to the winged 

 stage (11 J" & 16 ? ). We have photographs of all these eleven males, and 

 ten of them are reproduced on Plate 28, photos 7 to 14. 



There is a marked similarity between the abnormal features of this cross 

 and those of a cross between an Fj hybrid female and a pure variolaiius 

 male. To compare the breeding of these two crosses we will give, at this 

 point, a brief summary of the results from Record XI. 



Record XI. (p. 370). Fi Hyhrid $ X Pure variolarius <$ . — 119 eggs 

 were deposited between August 25th and September I8th. Only 36 of these 

 hatched. Eggs were deposited 12 times and mating occurred only once. 

 This pair did not mate a second time, though they were caged through 

 their entire breeding period, which, in this case, did not begin until 

 August 22nd *. 



The two crosses of Records III. and XI. resemble each other in the fact 

 that the mating of neither pair was normal, and that an abnormally small 

 proportion of their eggs hatched. They are unlike, however, in that almost 

 a normal proportion of the eggs of the cross of Record XI. showed the 

 initial stages of development. The development, however, was obviously 

 abnormal, and many of these eggs failed to hatch. Of the 36 eggs that 

 hatched, 26 were reared to the winged stage (18 S ^ ^ ? )• ^H ^^e males 

 were photographed, and are shown on Plate 34, photos 62-66. The pure 

 variolarius male of this cross is shown on Plate 34, photo 58. 



* 111 this connection it is interesting to note that an Fj hybrid $ (from variolarius 5 

 X ictericus (S ) that was caged with a pure ictericus S , mated normally through the entire 

 breeding season. The female, however, had been kept through the winter, and they mated 

 for the first time June 15th. 



