86 THE CANADIAN ENTOMOLOGIST. 



of the most detailed papers always gives the impression that something 

 is still wanting to explain the various facts related by the authors. Among 

 the Hymenopterous gall insects important progress was made in the 

 discovery by the late B. Walsh of the dimorphism of C. q. spongifica and 

 C. q. aciculata, the latter one a parthenogenetic species. But even here 

 new observations are wanted to fill some gaps in the history of those 

 species. Mr. W. F. Bassett, of Waterbury, Conn., draws my attention to 

 the fact that in a letter in the Proc. Entom. Soc. Lond., April, 1873, p. 

 xv., he " did state most emphatically his belief that all one-gendered gall 

 flies were the alternate of a two-gendered brood from galls of a different 

 form." 



Two papers by Dr. Adler, from Schleswig — " Contributions to the 

 Natural History of the Cynipidce," and " On the Ovipositor and on Ovi- 

 position of Cynipida?," in Berlin, Entom. Zeitschr., vol. xxi., 1877, Decbr., 

 which have just arrived here, are prominently remarkable. I believe the 

 way so long sought for is found, to understand the complicated relations 

 not only of the Hymenopterous gall insects, but probably of all other gall 

 insects, and perhaps, also, of some other insects not gall-producing. These 

 papers are equally remarkable both by the manner of the experiments, the 

 judicious conclusions drawn from them, and the clear and plain descrip- 

 tion of what he has observed. Ur. Adler has raised the species through 

 several years. In Cynipidas the raising is less difficult, as the eggs are 

 mature the moment the insect has passed its last transformation ; the 

 females are usually disposed to lay the eggs directly, and are, at least many 

 of them, not disturbed by observation ; therefore the experiments with 

 them followed through several years become more reliable. 



The parthenogenesis of Rhodites rosae was proved by direct raising 

 through three years. The fact is, indeed, more remarkable as males exist 

 in a very small number, about one to a hundred females ; but a copula- 

 tion was never observed. The females carefully separated after their 

 transformation, laid the eggs in confinement. Moreover, a number of 

 females were dissected and showed always the receptaculum seminis 

 empty, therefore proving that the eggs were not impregnated. 



Other series of observations lead to the interesting discovery of alter- 

 nating generation by a number of species, which were considered to 

 belong to different genera, but are now .proved to be the winter form and 

 the summer form of the same insect. 



Neuroterus fumipennis was raised from the galls, the imagines placed 



