some Parthenogenetic Chironomid. 227 
June 19. - Between July 5 and July 14 about seventy adults 
had hatched from these larvae, again all females; these, 
again, produced egg-masses parthenogenetically, and another 
generation of flies (twenty specimens, all females) appeared 
at the end of July. A third parthenogenetically produced 
generation appeared about August 20 and a fourth about 
August 31. From this time until early October flies and 
larvae were almost continually present (though in decreasing 
numbers), so that it became impossible to distinguish the 
separate generations ; but it would be safe to say that there 
were at least five parthenogenetic generations during the 
year, and though a careful watch was kept on the breeding- 
jar, no males were seen. 
The metamorphoses of Corynoneura are well known, and 
nothing need be said concerning this species, except that the 
food of the larvee appeared to consist of rather large infusoria 
(Paramecium ?) which swarmed in the breeding-jar. The 
larvee could be watched under a lens apparently chasing the 
infusoria, though I could never be quite certain that they 
swallowed them. When the numbers of the infusoria 
diminished, the Corynoneura larve also became much 
scarecr. Both had disappeared entirely by the middle of 
October. 
During the summer of 1918 I also reared a small number 
of males and females of Corynoneura celeripes, Winn. (or 
what I believe to be this species), from the pond which had 
provided me in 1917 with the first C. innupta, and also earlier 
with Chironomus clavaticrus, This species (Corynoneura 
celeripes), as already mentioned in the introduction, has 
been found by Goetghebuer to be occasionally partheno- 
genetic *, but I could obtain no evidence that such was the 
case with any of my specimens. Newly hatched females 
isolated in separate tubes did not deposit egg-masses, nor 
did they do so after males had been placed in the tubes with 
them. It would appear that in this locality C. celeripes has 
not the power of parthenogenesis, and the fact that I failed 
to obtain any eggs at all may be explained by the not unlikely 
assumption that it will not pair except under certain natural 
conditions. 
‘he species which I regard as C. celeripes appears to be 
* Since the European species of Corynoneura have not yet been criti- 
cally studied, it is, of course, possible that Goetghebuer’s species was 
relly the same which I have here described as C. innupta, rather than 
the one I regard as C, celeripes. Should that be the case, there is nothing 
new in my observations, but they would still form an interesting con- 
tirmation of Goetghebuer’s. 
